Month: July 2023

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The coordinate system used to define the parent model was NAD83 California Albers

The Sacramento River is a vital source of water for landowners and irrigation water suppliers in the Colusa Subbasin in addition to providing 80 percent of inflow to the Sacramento-San Joaquin Delta . The Glenn-Colusa Canal originates from the Sacramento River and flows through the Colusa Subbasin into Colusa County via the local canal system, providing irrigation water for the Glenn-Colusa Irrigation District, which is the largest irrigation district in the Sacramento Valley . The only principal aquifer in the Colusa Subbasin is contained in the freshwater-bearing sediments and stream channel deposits of the Modesto Formation, Tehama Formation, Riverbank Formation and Tuscan Formation, with the majority of the fresh groundwater in the project area contained within the Tehama Formation . Soils conducive to recharge, based on the SAGBI rating, range from excellent to very poor suitability, with the most suitable soils in the project area falling within the good to poor suitability range .Hydrologic conditions of interest in the project area include a natural cone of depression in groundwater elevation levels in the middle to southern half of the parent model domain . Based on recent groundwater monitoring data from the California Department of Water Resources , seasonal variations in groundwater elevation contours show a cone of depression forming in the center of the parent model domain during the Fall 2020 season due to stresses to the aquifer, such as excessive groundwater pumping for agriculture during the summer. Groundwater levels usually recover in the springtime, depending on how much precipitation occurred during the winter, but Spring 2021 contours still show lower groundwater levels in the same area with steeper groundwater head gradients,plastic garden pot as opposed to other areas in the parent model domain. Groundwater typically flows away from topographically high areas like the foothills of the Coast Ranges in the west, away from the Sacramento River in the east, and flows towards the topographically low areas where the cone of depression forms.

This area is heavily influenced by agriculture, and high amounts of pumping for agricultural use may be the cause of groundwater level depletion and the subsequent formation of the cone of depression and areas of low groundwater elevation.In 2019 and 2020, TNC recruited several landowners into their fall season bird habitat and ag-MAR incentive program. A total of 8 field sites were enrolled in TNC’s incentive program, which are all located in Colusa County, California . The nearest major cities to the ag-MAR sites are Williams, Colusa, and Meridian. The field sites modeled in this study are located near the city of Meridian, along the western bank of the Sacramento River . The fields are part of the Davis Ranches property. This area was chosen for the child model domain because Field 2 was the only field site that participated in flooding during consecutive years . The crop type grown on these fields is rice, but the fields were fallow during the period of flooding during the fall. The SAGBI recharge rating for the area in and around Field 2 and Field 15 are good to moderately good suitability for deep percolation in the soils .The data collected and used for the two groundwater models were primarily extracted from the Sacramento Valley Groundwater-Surface Water Simulation Model , which is similar to the California Central Valley Groundwater-Surface Water Simulation Model . Both SVSim and C2VSim were developed by the California Department of Water Resources, but SVSim is more specific to the northern Sacramento Valley, while C2VSim encompasses the entire Central Valley. Other sources of data include the California DWR, the United States Geological Survey , and Davids Engineering, Inc., the consulting company hired by TNC to conduct the field methods and technical analysis of the recharge program at each field site during 2019 and 2020. The data extracted from these sources were used in the MODFLOW model development process for parameterizing the packages for the parent and child models. More information on the development and calibration of C2VSim and SVSim can be found in Brush et al., 2013, and California Department of Water Resources, 2022, respectively. Layer stratigraphy data was extracted from SVSim, as were the layer and aquifer parameters, such as specific storage , specific yield , and vertical and horizontal hydraulic conductivity .

The layer stratigraphy and parameter data were used to define the aquifer parameters of all 9 groundwater model layers in both the parent and child models in their discretization packages. The uppermost layers in both models are relatively thin, with an average thickness ranging from 10 to 50 m. The lower layers are the thickest, ranging from about 50 to 200 m thick. The total thickness of all layers combined in both models is approximately 600 m . Each field site was flooded with a depth of 4 inches of water maintained for 30 continuous days during the fall, and 60 days of deep percolation data was collected , with deep percolation rates calculated for each site . These calculations were made using a mass balance approach – in which the inflows to the system are equal to the outflows – along with groundwater level measurements that were taken either periodically or continuously throughout the flooding period at groundwater monitoring wells adjacent to the field sites . Recharge took place at Field 2 during two periods, 9/18/2019-11/16/2019 and 9/17/2020-11/16/2020. Recharge took place at Field 15 during one period, 9/18/2019-11/16/2019. The average recharge rates at the three field sites ranged from 0.011 to 0.023 m/day . Deep percolation rates for all other days, or model stress periods, in the remainder of the domain are rates averaged by month from SVSim. Davids Engineering also monitored groundwater levels in four wells adjacent to the field sites . We used the groundwater level data provided by Davids Engineering for our child model’s head observation package. The average depth to groundwater between all four of the monitoring wells ranged from 5.3 to 7.7 m of depth . The software used for the models constructed for this study is the MODFLOW-2005 Three-Dimensional Finite-Difference Ground-Water Model developed by the U.S. Geological Survey . MODFLOW-2005, hereafter referred to as MODFLOW, uses packages that simulate the effects on groundwater flow processes of wells, rivers, lakes, and other relevant aspects and boundary conditions. A list of the packages used in both models is included in Table 4. MODFLOW can also vertically simulate aquifer systems with different geologic layers that may be specified as confined or unconfined. MODFLOW’s mathematical solution for simulating groundwater flow through the center of each cell in a model follows the partial-differential groundwater flow equation .The larger of the two models developed for this study was a steady state model that encompassed most of the area of Colusa County . As is the case with steady state models, all model parameters remained constant over a specified amount of time,draining pots so all input data that varied over time were averaged to one value for input.

The purpose for making the large model steady state was to have all inputs to the system equal to the outputs, stabilizing the system as a whole. This provided a more general simulation of the regional hydrologic processes , which allowed for faster model runs and processing times. The results of this large steady state model provided information on flow magnitude and direction that was used to constrain the boundaries of the child model. The domain for the large model spans an area of approximately 160,000 square meters and includes 9 layers, modeled after the layers in SVSim.The parent model has 140 rows and 113 columns, with a cell size of 400 m × 400 m. The number of stress periods, or days, is 1 since the parent model is run under steady state conditions. The boundary conditions used to define the model domain include 2 general head boundaries , 2 constant head boundaries , and the river package to simulate the effects of rivers, streams, and canals that flow through the model domain . The smaller of the two models developed for this study was a transient model that was located within the area of the parent model domain, including the ag-MAR field sites . Since the child model is transient, all data input for each package varied over time. The starting date of the child model was defined to be 8/18/2019, one month before the flooding occured, and the end date of the model is 11/16/2020, the last day of the flooding period. Like the parent model, the coordinate system used to define the child model was NAD83 California Albers. The child model has 58 rows and 58 columns, and each cell in the model has a size of 100 m × 100 m. The number of stress periods, or days, included in the child model is 456. Groundwater fluxes and directions of flow were extracted from the results of the parent model in order to inform the boundary conditions of the child model . The well package was used to simulate those fluxes. We defined the flux from each well in all model cells on the child model’s boundaries to represent the general flow that occurred in the same area of the parent model. In more specific terms, cell-by-cell flow data was extracted for each cell in every layer from the parent model, and the cell-by-cell flows were used to inform the groundwater fluxes at the boundaries of the child model. We also used the River package to represent the small part of the Sacramento River that acts as the eastern boundary of the child model. However, the RIV package is only present in the first layer of the model, so we used the GHB package for the eight layers directly below the river cells. The recharge package was used to represent the 2019 and 2020 ag-MAR field sites, with deep percolation data from Davids Engineering.Three different scenarios were run using the child model to test different parameters and their influence on the hydrologic response seen in the model outputs. The three scenarios were designed to assess whether the timing, frequency, and amount of recharge significantly influences the hydrologic results of the child model. Scenario 1 was the baseline model run, using the original and unaltered deep percolation data from Davids Engineering. No alterations or calibrations to the model inputs were made for this scenario. For Scenario 2, we increased deep percolation rates from Davids Engineering by one order of magnitude to ascertain whether we could see a significant hydrologic response. Only the deep percolation data was altered for Scenario 2; all other inputs remained the same as Scenario 1. It should also be clarified that a tenfold increase in recharge rates is not realistic. However, we wanted to test this hypothetical extreme solely to see a significant response. For Scenario 3, we increased the duration of recharge to span ten years.

We chose to use the 2019 deep percolation data, and repeated that year ten times to see how increasing the duration of recharge would affect the child model results. The 2019 deep percolation data input for Scenario 3 was unaltered; only the duration of recharge and the time discretization of the child model was increased to span ten years. Scenario 3 was designed to represent ten consecutive years of implementing ag-MAR on these field sites.The results analyzed from the steady-state parent model include model performance plots and model outputs. We assessed the performance of the parent model with a one-to-one plot of the observed heads that were input into the model, with the simulated equivalent heads that the model calculated at each groundwater monitoring well in the parent model domain . The different colors on the plot represent the binned data of the residual heads, which were calculated as the difference between the observed and simulated equivalent heads. The different bins represent different groups of residual data ranges. The gray line represents the line of equal values, or one-to-one line, between the observed and simulated equivalent heads.The same binned residual head data were plotted on a map of the parent model domain, showing the location of the groundwater monitoring wells and the residual head value . Like the residual head bins plotted in the one-to-one plot in Figure 12, the bins for the residual map were calculated from the difference between the observed and simulated equivalent head values at each groundwater monitoring well on the map.

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Trees and other types of vegetation are then planted in this new built environment

In the case of citrus, for instance, a globally important fruit crop that is often heterozygous for important trait genes, protoplast regeneration can be achieved only if protoplasts are derived from juvenile tissues. However, plants generated from juvenile citrus tissues require years to reach a mature fruit production stage, and this delay is an impediment to the efficient evaluation of gene functions in fruit and for other genes pertinent to citrus breeding programs. On the other hand, tissues from mature citrus trees, such as shoot segments, can be transformed with Agrobacterium. Jacobs et al.discussed the possibility of using Agrobacterium-mediated transient expression of Cas9 and sgRNA genes to produce non-transgenic mutant plants. Iaffaldano et al.reported the production of CRISPR/ Cas9-mediated mutant plants using Agrobacterium without any selection of stable transgenic plants. However, Iaffaldano et al.did not characterize whether their mutant plants were transgenic or non-transgenic, nor did they calculate the percentage of each type. The nontransgenic mutation rate reported in this study is lower than mutation rates for the previously reported protoplast micro-injection methods but higher than for particle bombardment methods. However, Agrobacterium can be a more versatile tool because of its ability to efficiently infect many different tissues types across most plant species, and it is the most widely used method for plant transformation. Thus, protocols for Agrobacterium infection and subsequent callus and shoot regeneration are readily available for many crop plant species. Furthermore, even when other methods are applicable, Agrobacterium infection procedures are relatively simple and easy to perform for many plant species. Thus,draining pot the method presented here provides an alternative method for the production of non-transgenic mutant plants.

Our method of using Agrobacterium to transiently express CRISPR/Cas9 genes, without the use of chemical selection such as kanamycin, also offers some other advantages. The lack of a chemical selection agent following Agrobacterium infection allows for even greater rates of plant regeneration compared to when chemical selection is used and therefore likely enhances mutant callus/shoot production. This is because selection agents, such as kanamycin, hygromycin, and various herbicides, can suppress shoot regeneration for many plant species, even when those shoots express relevant resistance genes. Furthermore, our high-throughput screening method, based on a novel DNA sequencing strategy in combination with HRM analysis, makes mutant identification fast and easy to perform. The drawback of our method is that there is a risk of creating transgenic mutant plants; however, identifying and discarding these plants does not add any significant time to the screening process. We have observed that the threshold of mutant plant detection using the Illumina sequencing method can be much more sensitive than the detection of one mutant out of 42 plants described in this study. The use of the 42-plant sample pools, therefore, assures that the presence of a mutant plant can be readily detected in pooled samples. Additionally, the threshold of HRM analysis to detect mutant plants can be as low as 1 of 19 plants, but we chose one out seven . Again, this pooling choice provides a safe margin for error by reducing the chance of missing mutant plants due to false negatives. Furthermore, a small number of false positives from the sequencing analysis of 42-plant pools are not a concern because they can be easily identified in the subsequent step of screening. Thus, our method, which combines a unique DNA sequencing strategy with HRM analysis, provides a reliable protocol to screen for CRISPR/Cas9-mediated mutant shoots from a population of shoots regenerated in the absence of selection pressure. The overall protocol for mutant identification is schematically represented in Supplementary Figure 4.

Using this protocol, it would take ~14 days to identify all mutants from 1000 independent shoots that were subjected to Agrobacterium-mediated transient expression of CRISPR/Cas9 genes. In conclusion, we have developed a highly useful method utilizing Agrobacterium-mediated transient expression of Cas9 and sgRNA genes combined with multi-step pooled screening, enabling the reliable production and efficient identification of non-transgenic mutants regenerated in the absence of selection pressure. Due to the versatility of CRISPR/Cas9 and Agrobacterium-mediated infection, as well as the ease of plant regeneration from leaf, shoot, or root explants, this method is applicable to many economically important plant species, particularly heterozygous perennial plant species that are recalcitrant to regeneration from protoplasts or following biolistic bombardment.Urban trees are garnering increasing attention in this era of interest in biodiversity and urban sustainability. There is growing recognition that urban areas are largely the result of human decisions and actions – they are constructed spaces. When cities are designed and built, for example, local vegetation is usually removed, and the earth recontoured and/or excavated to facilitate construction.The species chosen can be culturally, historically, or functionally significant, but it is logical to think that species planted are generally representative of species available from the local nursery industry at the time and may or may not draw from the native flora of a regional ecosystem . Regional nursery catalogs as a data source for urban biodiversity have not been evaluated prior to this research. Yet, the horticultural industry has been shown to be an important contributor to regional biodiversity with regard to invasive species distributions . This paper contributes to the literature on urban biodiversity by suggesting that plants offered by nurseries are a source of yetto-be-explored diversity in cities. We hope that this research will encourage the further consideration of the role of nurseries in urban biodiversity. The significant historical legacy of tree introductions by European and Eastern U.S. settlers in California likely accounts for the initial urban tree diversity of Los Angeles and Southern California. The early 17th-century missionaries came with a culture of planting both crop-yielding and ornamental trees and this tree palate was substantially supplemented with the advent of the intercontinental railroad and increased oceanic traffic connecting Southern California with the world in the 19th Century.

An innovative horticultural industry emerged in California which both catered to, and shaped the tastes of, settlers . Today Los Angeles has an exceptionally diverse tree assemblage where the imprint of this early period can still be detected. Referred to as the Garden of Eden, Paradise, and the Garden of the Hesperides throughout its relatively young history, images from this region spread worldwide . There are a number of historical and social factors that can shape and influence tree species composition and diversity in cities beyond biophysical ones such as climate, environment, and ecological factors . Cultural factors , and factors related to symbolic and representational associations of trees are also important. However, one possible critical factor in the planting and distribution of trees in the urban environment that has not been investigated previously, and is certainly related to the factors above, is the selection of tree species available from the nursery industry of the region. People obtain trees from purveyors,round plastic planters and thus this article examines the evolution of the selection of trees available from tree nurseries and seed availability. If there is no stock or seeds locally available, the burden of finding a desired tree is much higher. Thus we suggest that a window into which trees are found in the urban fabric may be by examining nursery catalogs over time. This paper describes results from a longitudinal study of nursery offerings of tree species from 1900 to 2010. Los Angeles County has around 6 million trees in a bio-region that naturally supported trees only along riparian corridors and along the foothills of the cityregion . As Schoenherr and Rundel and Gustafson have documented, in pre-colonial cismontane Southern California was dominated by chaparral and coastal sage scrub. Trees were mostly found in riparian corridors and along the foothills and included 14 native species. To understand the role of the landscape nursery industry in influencing diversity of the tree canopy cover, we developed three main areas of inquiry. First, we examined whether there has been a significant change in the number of tree genera and species offered by tree nurseries over time. Second, we asked whether there have been significant changes in the functional classifications of trees offered over time. Finally, due to the size of the data set we were curious to know whether some species had been offered consistently from the early 1900s to 2011.The limited historical documentation available from the California Department of Food and Agriculture was supplemented with archival catalogs. We located two nursery catalog collections in the region: Collection of Nursery Catalogs in the Department of Special Collections located in the Charles E. Young Research Library, University of California, Los Angeles, and the collection of catalogs available at the Los Angeles County Arboretum and Botanic Garden Library. The 2009 and 2011 catalogs of West Covina Nurseries and Monrovia Nurseries, both large and well known nurseries in the region, were accessed on the company’s websites respectively . We exclusively utilized catalogs of nurseries located in Los Angeles County. Data collection involved manually transcribing tree species information from each catalog into a database for further analysis. Species that were 12 feet and taller were classified as trees in this analysis. Images of the catalog pages were scanned and converted to text using optical character recognition software. The location of the nursery, the year of the catalog, scientific name, and names of varieties were recorded. Information was also collected for commercial fruit trees but is not included in this analysis. In order to classify the tree as deciduous or evergreen, native or non-native , angiosperm or gymnosperm, we used the Sunset Western Garden Book . Gymnosperms were classified as tree species belonging to Araucariaceae, Cupressaceae, Ginkgoaceae, Pinaceae, Podocarpaceae, Sciadopitayaceae, and Taxaceae families .

Tree fern species were classified as ferns. Catalogs were chosen to represent every decade from the 1900s to the 2010s. This 110-year period was split into four periods of 30 years each in order to conduct the statistical analysis, because the numbers of catalogs represented in each time period was different . A total of 18 unique nursery catalogs were sampled for this research. The number was restricted by availability in the archival collections. The number of catalogs sampled in each time period differed such that period one had three catalogs, period two had four catalogs, period three had six catalogs, and period four had five catalogs. We streamlined the study design by sampling at least one nursery catalog to represent each decade . While it is likely that having more catalogs, and in turn, having a larger sample size, especially in the earlier decades, would have yielded more robust trends and results for the earlier decades, it is unlikely this would have changed the overall results.The large data set was then analyzed using both Microsoft Excel 2011 and MATLAB 10. MATLAB was used to obtain specific numerical information . Using a statistical count model we were able to predict the number of species offered in each time period; we suspect that the difference in number of catalogs sampled would have little to no effect on the actual number of species offered, thus the overall result would still not change. The entries were optimized manually to account for spelling errors, alternative names, and repeats. In order to compare the time periods and the different numbers of catalogs sampled in each time period, we employed a negative binomial regression count model. This allowed for comparison between time periods by predicting the number of species offered in each time period. One goal of the analysis was to identify whether there was a statistically significant difference in the number of species throughout the time period, and we found there was with a 95% confidence interval. A polynomial contrast was used to detect linear and quadratic trends with time. An exponential model was also used to analyze the same data. However, unlike the count model, the exponential model did not take into consideration the difference in the number of catalogs used in each time period. While the results indicated that both models fit the data, we chose to use the negative binomial regression count model because it took into consideration the differences in the number of catalogs used in each time period.We also found that there were fifteen species offered consistently in every decade.We used the nursery catalogs to identify wholesale and retail nurseries, and city websites to identify cities that had municipal arborists.

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Sustainable development is now globally accepted as a supreme long-term goal of humanity

The recent publication of two almond reference genomes and the increasing availability of quality genomic data opens opportunities to complement our study and obtain more complete and accurate pedigrees based on genomic variability. This kind of studies can be useful even when some genotypes were discarded due to breeding process, as is the case in our almond pedigree work. Although almond showed a higher genetic variability than other Prunus species, the historical expansion of almond from the Mediterranean region to California and from California to Australia could have caused a bottleneck effect in the breeding population under study. Different studies have reported a high genetic relatedness between Australian and Californian cultivars, possibly caused by the introduction of a limited number of cultivars from Europe to these countries. In addition, breeding programs worldwide have used cultivars from French origin as main founders as Aï, Princesse, Ardechoise, Nonpareil, IXL, Ne Plus Ultra, or Nikitskij. This situation could have led to an underestimation of relatedness and inbreeding. The use of large-scale genomic data would provide most valuable information in this respect,plastic pots plants expanding the almond pedigree beyond breeding records.Man’s interaction with nature is rapidly becoming more complex due to a multitude of activities that directly or indirectly cause a disturbance in the natural system. The deeper interactions between human activities and natural ecosystems call for an interdisciplinary approach to natural resources management, while the inputs from multiple disciplines need to be effectively utilized in achieving it. This prudent natural resources management will enable sustainable development of a region without losing the resource base. Sustainable development essentially aims to reconcile conflicting objectives of economic development and improvement in human welfare, and ecological sustenance and functioning of ecosystems.

The term sustainable development is defined by the Brundtland Commission as “the development that constitutes meeting needs of the current generation without compromising the ability of meeting needs of future generations” .Sustainable utilization of natural resources is essential for sustainable development. It follows that the sustainability of renewable natural resources in general and common property resources in particular assumes importance in both developed as well as developing countries because of the finite capacity of the resource base and the increasing demand for its exploitation. The technical definition of the term sustainability is given as, “the ability of a natural resource system to produce a socially optimum level of output that is necessary to meet the needs and aspirations of the people dependent on the system perpetually without any detrimental effects on the resource system itself and the physical environment, and with no imposition of significantly greater risks on future generations” . This might be comprehensive and deep rooted, but in other words, sustainability implies not only conserving natural resources but also maintaining ecological functions and the supply of natural resource products, which are essential to the livelihoods of local people. Sustainability in this sense is a dynamic concept that reflects changing levels of output corresponding with changing human needs and production technologies over time.Natural resources discussed here are broadly covered under land, water, and biomass . These three resources are crucial for production under various systems namely, agriculture, horticulture, silviculture, pisciculture, and animal husbandry. Management of these three major resources is crucial for making production in these systems sustainable and enhanced. Sustainability of these systems can be threatened due to disruption in the linkages between these resources. This may assume various forms, for example, increased soil erosion resulting in nutrient loss rendering it unfit for use in the case of land; soil water deficiency or excessiveness affecting its productivity and degradation in the case of water resources; decline in vegetation density and diversity leading to reduction in soil and water conserving properties in the case of biomass or vegetation resources, and so forth. A more detailed discussion of these follows.

Soil productivity can be defined as those properties of soil that influence crop production. The increased yields from better-managed soils are due to increased inputs and improved practices rather than with improvements in the basic fabric of soil . In recent years the sediment derived from soil erosion has been the major non-point source of pollution in surface water bodies while loss of in-situ topsoil has caused reduction in productivity. Erosion reduces long-term production potential and seldom improves the immediate capacity of eroded soil to sustain plant growth or produced crops . Results of recent studies show that soil physical and biological properties seem to be the predominant constraints to maximizing plant production on eroded soil, compared with chemical and fertilizer constraints. For example, Rosenberry, Knutson, and Harmon suggested that yields generally decline as soils shift from one erosion phase to another, even with increased fertilizer. This is attributed to surface soil physical and biological properties. However, in addition to irrigation, other water management techniques, such as surface mulching, can also be applied for amelioration of eroded soil. Crop productivity is also affected by moisture availability in soil. In the post-green revolution, particularly in the 1980s, instability in crop productivity increased on account of the rise in sensitivity of output to variations in rainfall in India . This increasing vulnerability of agricultural output to variations in rainfall, particularly during droughts when the soil moisture is scarce, is attributed to inadequate expansion of irrigation by these same authors. It is minor irrigation, which is not given priority that can be part of the strategy under watershed development. Similarly, decline in water quality has affected crop productivity in saline and alkaline lands that were created by excessive irrigation or polluted water in northern parts of India. At the same time, vegetation adds much to resource endowment and has crucial linkages with soil and water. Good vegetation cover functions as a soil and water-conserving agent, whereas, lack of vegetation will make the soil vulnerable to erosion and allow water to flush off the sediments. Biological diversity of vegetation is crucial in the survival of the vegetation itself and the sustenance of the ecosystem in that region. In fact, planning based on land use can effectively conserve soil as well as water. This is little elaborated under Production Systems Planning .

A distinction, however, needs to be made between the goals of attaining sustainability and of increasing productivity. While higher productivity may be required to achieve the sustainability goal, the requisite increase in productivity must be achieved in a manner that will not jeopardize the ability of a natural resource system to meet future needs. In other words, it is possible to achieve increases in productivity through unsustainable short-term approaches . The term watershed denotes the area defined by natural boundaries characterized by terrain , soils, and drainage delimitations. Watershed is an appropriate unit for environmental planning for sustainable management of natural resources of a region. Watershed Management is a practice of conserving soil, water, and biological resources using scientific principles,plastic nursery pots traditional and systems knowledge, and local resources with an objective of increasing crop productivity. It involves rational utilization of land and water resources for optimum production with minimum hazards to national resources. It essentially relates to soil and water conservation in the watershed which means land use according to land potential, protection of land against all kinds of deterioration, building and maintaining soil fertility, conserving water for farm use, proper management of water for drainage, flood protection, sediment reduction, and increasing productivity for all kinds of land uses . Watershed management has come into focus in India with the advent of productivity fluctuations with rainfall, necessitating micro-irrigation in drier parts, and also with the advent of space technology tools, which are useful in the micro-level planning. Land water related management projects and schemes have been implemented under various programs since the beginning of the Five Year plans. In particular, the third Five Year plan introduced the watershed as the basic hydrological unit for soil conservation planning and execution . Increased emphasis on watershed development programs for dry land plain regions in India, inter alia, is a manifestation of the shifting priorities in the agricultural sector, which until recently concentrated mainly on crops and regions with assured irrigation . Successful case studies of Ralegaonsiddhi, Myrada, are well known . In the sequence of evolution of natural resources management using the watershed approach for sustainability of these resources, thrust is on the productivity of natural systems. It is the productivity of natural systems that needs to be conserved through planning so that the needs of an increasing population are met and the threat to their renewability is thwarted. The watershed approach is an ideal approach to carry out a planning operation, and its planning framework shall fit well under the implementation and execution activities. Central to the success of the process is the participation of the population during the crucial implementation. Production systems planning is a method of planning for the use of natural resources under the watershed approach with a focus on ecological characteristics. It essentially involves spatial allocation of land use for various production systems, namely, agriculture, horticulture, and animal husbandry, by which conservation goals are met through better decision-making. PSP is similar to regional land use planning, but it differs from it in that it depends on ecological characteristics at the watershed level rather than activities at the regional level. However, in both cases land use is an important element.

The role of production systems in soil and water conservation is evident from the water and soil losses of catchments under such production systems such as mentioned by Mallik . Fruit development is mediated by plant growth regulators that control its major developmental processes. As grape berries develop, they exhibit a double sigmoid growth curve separated by veraison that marks the beginning of ripening. Cell division and expansion are the major events during the first phase and are accompanied by synthesis and accumulation of organic acids, methoxypyrazines, and phenolic compounds such as proanthocyanidins and hydroxycinnamates. This phase of berry growth is under the control of auxins, gibberellins, and cytokinins. Auxins and gibberellins are mostly produced by the seeds while the source of cytokinins in fruits is less established and it is likely to be imported from the plant. The number of seeds in the berry can determine berry size, and the lack of seeds or the presence of unfertilized ovules in sternospermocarpic berries can be partly complemented by external gibberellin. Schematic representation of the levels of PGRs during development suggests that auxin levels are high at berry set and decrease during phase 1 while cytokinins and gibberellins peak during phase. The second phase, verasion, marks the beginning of major processes in grapes ripening, berry softening and anthocyanins accumulation in colored varieties. There are reports of a small peak of ethylene preceded by a large peak of abscisic acid which coincide with veraison. Brassinosteroids increase at veraison and participate in ripening, possibly by modulation of ethylene content. On the other hand, auxin treatments retard sugar andanthocyanin accumulation and prevent the decrease in acidity and chlorophyll concentration, and also cause a delay in the usual ripening-associated increase in the levels of ABA. The third phase in berry development is ripening which is characterized by accumulation of glucose and fructose, as well as a decrease in the levels of organic acids. Volatile compounds that are produced by grape berries during development and ripening include fatty acid derivatives that are the most abundant group, monoterpenes that are prominent flavor compounds in Muscat flflavored grapes, sesquiterpenes, C13 norisoprenoids, volatile sulfur compounds, and methoxypyrazines. Some volatile compound types such as methoxypyrazines and sesquiterpenes, C13 norisoprenoids and volatile fatty acid derivatives accumulate in the berry before veraison while volatile monoterpenes and volatile sulfur compounds accumulate during ripening . Physiological studies on the role of PGRs in fruit development often rely on external applications of the hormones or their agonist followed by observations of the changes in fruit development. In table grapes there is a plethora of applicative studies aimed at increasing the berry size in ‘seedless’ varieties and the color of red varieties grown in hot regions. The effect of GA was studied from the late 1950s with timing and concentration being major factors. In ‘seedless’ grapes, application of GA to increase berry size is performed at a fruitlet diameter of 4–6 mm because earlier application can have negative impacts on fruit-set and berry shot and later application is less effective.

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Enhancing tree nutrition has also been reported to increase fruit set rates

In the post-independence period India relied on Green Revolution technologies to increase production of staple cereals such as wheat and rice. This historical approach to ensuring food security has repercussions for contemporary conversations about hunger. Namely, my interlocutors considered national food insecurity to be an issue of the past. As an official in the Karnataka Department of Horticulture told me, India has now achieved food security due to the impact of Green Revolution technologies. He said that after independence, India was most concerned with becoming self-sufficient in food grains, and was unconcerned with the long-term effects of inputs like pesticides and hybrid seeds: India was “not concerned with [food] quality” because quantity was the most critical concern. However, in the 1980s, he suggested, the Indian government began thinking about how to provide “high-quality foods,” once the “rush to feed more people was lessening.” Between the production plateau of the 1990s and the increased knowledge about the effects of pesticides on human health, he said, India must now think more about food quality than quantity. This narrative—of achieving national food security and turning to other concerns—is linked with a broader understanding of the changing economic landscape in post-liberalization India. The majority of my interlocutors were preoccupied with two problems in this context: the “agrarian crisis,” and rising food safety and health concerns. While these problems affect diverse actors, they are primarily the concerns of the middle classes. Sociologist A. R. Vasavi has shown that the agrarian crisis—characterized by debt and economic insecurity that she attributes to the individualization of risk in the post-liberalization period—most severely affects small landowners. These forms of agrarian distress do not capture the insecurities of the poorest and most marginal members of agrarian communities,garden plastic pots including landless laborers and subsistence farmers .

Efforts to address the agrarian crisis are thus focused on addressing the concerns of landowners. Similarly, as I argue in chapter 3, the farmers who benefit from the creation of new intermediary forms are neither the most privileged nor the most marginal members of their communities. Just as the concerns about agrarian distress and the projects that they motivate are anchored in the middle strata of agrarian society, efforts to ensure food safety are rooted in middle class concerns and desires. In India today, fears about food contamination and adulteration are on the rise, and food safety scares generate intense concern about food quality and health. These concerns are not restricted to the middle and upper classes—the Maggi noodles scandal in which Nestle’s immensely popular packaged noodles were found to contain undisclosed MSG additives and above-threshold levels of lead caught the attention of a wide swath of the public, likely because these noodles are consumed across class, caste, and religious divisions . However, as I show in this dissertation, companies that claim to provide “quality” fruits and vegetables—a claim that is often conveyed through third-party certification programs like organic or GLOBALG.A.P—target the urban middle and upper classes. More accurately, they cater to consumers who are members of the established middle and upper classes. They are justified, however, along the narrative of the emerging middle class and its growing appetite for global foods and awareness about food quality and health. The conversation surrounding both of these problems—the agrarian crisis and food safety concerns—offer certain solutions in favor of others, and in so doing, address some challenges and audiences rather than others. Specifically, I show that the two interventions considered in detail in this dissertation—the creation of new intermediary companies and gardening among urban professionals—are class-specific answers to class-specific problems. This point is critical because these projects establish new forms of food distribution that will replace or reconfigure Bengaluru’s supply chains. In this way, these projects are part of the same patterns of exclusion and dispossession at the heart of urban development policies that privilege middle class concerns and desires .

This dissertation offers ethnographic insight into shifting food supply chains in order to understand how changing urban and agro-environments, class structures, production methods, and consumption patterns intersect in class-specific experiences of Bengaluru’s shifting food ecologies.This is in part due to the inextricable relationship between food, the body, and place. As scholars have long identified, food is a symbolic and material force that transcends and delimits particular places and communities.Appetites and aversions are inseparable from power structures . In his essay on “gastropolitics,” Arjun Appadurai details what he calls “the biophysical propensity of food to homogenize the human beings who transact through it” . In the South Asian context, this propensity makes eating a particularly powerful, and potentially transformative, practice. Food is at the center of South Asian understandings of self and other, and, as Appadurai suggests, the limits of this distinction. The “homogenizing” qualities of food lend a particular character to concerns about food safety and health that are closely linked with place. Harris Solomon argues that experiences of ingestion are central to how urban Indians understand and mediate risk in their daily lives. He uses the framework of metabolism to consider the porous relationship between bodies and the urban environment in Mumbai, suggesting that concerns about obesity and food safety are connected with the lived experiences of life in the city. The homogenizing and porous qualities of food are realized not only through ingestion, as Appadurai and Solomon each identify, but also through supply chains, as forces that link, for example, fields, delivery trucks, store shelves, and bodies. In the processes of supply chains, objects, environments, and practices blur. For example, as sites for production and processing practices that are undetectable to the end consumer, supply chains illuminate the intimate yet often invisible relationships between actors embedded in the food commodity. It is in this porosity that supply chains illuminate the inequalities, insecurities, and aspirations that characterize shifting food ecologies.

While the majority of existing analyses of food supply chains focus on global markets and commodity networks, this dissertation analyzes the regional fresh fruit and vegetable supply chain that connects urban consumers in Bengaluru with nearby farmers. Focusing on the regional fresh fruit and vegetable supply chain opens up a critical issue that speaks to larger questions about what makes food “good”: the proximity between producers and consumers. In India today, managing the circulation of highly perishable commodities remains a challenge—refrigerated transportation is rare, as are infrastructures such as ripening chambers, and basic utilities such as electricity remain sporadic. These limitations mean that highly perishable food is necessarily local. Given the rising influence of the local food movement that envisions local supply chains as an answer to the ills of the industrial food system , India offers an interesting case study to understand the potential manifestations and effects of highly localized supply chains. It also opens up new ways to interrogate the discourse of locality shaped by the local food movement: How do the geographic mobilities and temporal rhythms of the supply chain change between perishable and non-perishable food commodities? What different understandings of locality, quality,raspberry plant pot and authenticity are produced in a place where supply chains are largely restricted by the inefficacies of infrastructure rather than the desire to “go back” to localized food networks? What relationships between farmers and urban consumers emerge in this context? The last question gets at a key dynamic at the heart of this dissertation: the changing relationship between the country and the city in the context of a rapidly expanding cityscape. The relationship between the city and its outlying communities has consequences for ecologies and economies that transcend the categories of urban and rural. Supply chains help us envision the interconnections that complicate the urban-rural dualism. William Cronon’s Nature’s Metropolis: Chicago and the Great West sheds historical light on how Chicago’s hinterland was critical to its creation as a metropolis. By following wheat, lumber, and meat into the city, and tracing how urban markets in turn changed the countryside, Cronon argues that the distinctions between nature and culture and rural and urban are artificial. Rather, the natural resources of the countryside are instrumental to the city-building process. Similarly, this dissertation follows fruits and vegetables to trace the interconnections among agrarian and urban communities. I show that urban consumers’ insecurities and desires are inextricably connected with those of peri-urban producers, highlighting the spaces and practices of overlap between the city and its agrarian countryside. However, my goal in so doing is not to refute the lived reality of the rural-urban divide. For the people who occupy spaces categorized as urban or rural, the inequalities embedded in this distinction are very much real, with concrete manifestations in their daily lives. This dissertation engages with these categories and the lived experiences of overlap and divergence in order to explore how city residents and nearby farmers understand and experience the effects of the rapidly expanding cityscape on their present lives and possible futures.

For each, food offers a narrative locus, embodied experience, and site of intervention into the ambiguities of urban development.Alongside the shifting materialities of food ecologies are changing ethical understandings and practices of food and agriculture. In Bengaluru today, the term “market” is used extensively among English- and Kannada-speakers, villagers and city residents alike. For the majority of my interlocutors, the market represents both the problem and solution—access to the urban market provides an opportunity for higher incomes among farmers, but is also a source of widening disparities within and between agricultural communities. Among urban consumers, the market is seen as both the source of contamination and generative of better options. This attention to the market both reflects and informs a wide variety of changes to Indian agricultural commodity markets and their linkages . In India today, the market is understood to be anchored in the laws of supply and demand. However, this coexists with the belief that the government can and should intervene to make the market fairer and more effective. I heard from many farmers, for example, that the government should support them by better connecting them with the market. This approach to the market defies any easy separation between political context, social responsibility, and market forces. Despite the language of the “free market” that sets economic forces apart from the sociopolitical landscape, scholars have demonstrated that markets are in fact performed and produced . Rather than existing in a sphere separate from social norms, markets become sites to contest moral grievances .Grower attention has been focused on increasing orchard yields for decades and research efforts have been aimed at improving almond orchard productivity through the optimization of all variables involved in nut production. Fundamentally, almond tree yields are the product of the number of kernels produced per tree and kernel weights. Of these two factors, the number of kernels is the most important since kernel weight is generally not a factor of paramount importance for growers . The reproductive process in almond trees involves two years from flower bud induction to fruit set and fruit maturity. In this process the number of flowers borne and the number of flowers that set fruit determines the final kernel yield per tree. Fruit set in almond is strongly influenced by presence of pollinizer cultivars, insect pollinators and by climatic conditions affecting pollen viability, germination and pollinator activity in addition to general tree health. In 1959, Kester and Griggs stated that “the question often arises as to whether or not the fruit set for specific almond orchards could be increased by using more bees and pollinizers to effect more complete cross pollination”. Mean relative fruit set in almond has been reported to be about 30% but there is large year-to year variability that can make it range as low as 5% and as high as 40% . These relatively low fruit set percentages offer a potential margin for almond crop improvement. Accordingly, almond orchards are planned and managed to improve relative fruit set by planting pollinizer rows on either side of the main cultivar rows to increase availability of compatible pollen . The use of bees in almond orchards during flowering increases the likelihood of movement of pollen among trees .

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This interpretation correlates well with the position of three TGAT core motifs

Transcription factor binding sites were identified by consulting multiple online prediction tools which quickly found over two hundred predicted cis-motifs, many of which had low probability scores. The odds of identifying functional cis-motifs were increased in a few select cases by adding 5bp sequences on either side of the core motif, based on previously identified target sites for WUS , ARF1, and ARR1. The enlarged biding sites were then mapped to the CLV3 genomic sequence, tolerating up to 2 mis-matches in the flanking regions. In order to account for the presence of transcription factors whose cis-motifs are not currently known, MEME analysis were employed to identify motifs shared between genes that are co-expressed with CLV3. Overall, 231 potential cis-motifs and transcription factor binding sites were identified. Most were randomly distributed over the entire CLV3 genomic sequence, but irregular clusters could be recognized near the coding region. The largest cluster occurred in the upstream 500bp of the 5’ promoter, while up to three smaller clusters occurred in the 3’ enhancer region . The list of potential factors was then filtered to include those found inside the previously identified CLV3 regulatory regions, which left just 157 predictions . Many of the remaining predictions were found to have overlapping sequences, though it is unclear how well this might predict their actual function in-vivo. One notable example of this phenomenon is a predicted MYB-like binding site located at -155bp, which was predicted by four different databases. In other cases, two structurally different transcription factors were predicted to have overlapping cis-motifs, such as the bZIP/homeodomain pair Opaque-2/ALFIN-1 in the 3’ enhancer region. Interestingly,large plastic pots for plants the data also revealed four partial miR414 targets, three of which overlapped with the DNA/Mariner family transposable element At2gTE50670 in the 3’ enhancer , and the fourth occurred in the 3rd exon.

In an alternative approach to identify unknown cis-motifs, phylogenetic footprinting was used to compare CLV3 orthologous sequences from different species. In this method, functional regulatory structures can be identified by their conservation over evolutionary time, which often requires little more than performing a sequence alignment. The method is also quite robust, as previous studies found that the identified footprints matched 80 and 85% of known transcription factor binding sites. To begin this analysis, three CLV3 orthologs were identified by their syntenic relationships within the Brassicaceae using the tools in the Brassica Genome.org database. Their cDNA sequences were aligned with 27 CLE family paralogs identified in A. thaliana in order to identify features that were unique to CLV3 orthologs, before expanding the search to additional species. This analysis revealed three potentially unique traits that might be used to distinguish orthologs from the multitudes of closely related CLE genes. These included three consecutive histidines at the C terminal end of the CLE motif, a C-terminal oligo extension, and a 3-exon gene structure, all of which had been previously identified in the CLV3 sub-group. Additional orthologs were then identified using tBlastn searches against the AtCLV3 protein, for which nine species which met the criteria described above: Brachypodium distachyon, Oryza sativa, Ricinus communis, Glycine max, A. thaliana, Arabidopsis lyrata and Brassica rapa, Capsella grandiflora, and Camelina sativa. No AtCLV3 orthologs were identified in the gymnosperms, basal angiosperms, or the Asteriids using these search parameters. The Euphorbiaceae and Fabaceae each contributed one species in the closely related Eurosiids I, while the monocots are represented by two species in the Poaceae. As a result, this sampling is heavily biased towards the Brassicaceae family , which provide more than half of the total number of species. In order to footprint the promoter regions, initial sequence alignments were performed using 8kb genomic fragments, containing up to 5kb of upstream and downstream sequences on either side of the coding region. However, little or no homology was found when all nine orthologs were aligned simultaneously. This was not improved by removing monocot clade, as the two grass orthologs failed to align with each other.

Repeating this pattern, both R. communis and G. max also failed to alignment with each other, or with any of the remaining orthologs. In contrast, conserved regions became clearly visible when the five Brassicaceae species were aligned separately . This result appears to reflect the optimum degree of sequence divergence for this gene, as previous studies have found that orthologs outside of the Brassicaceae were less informative due excessive divergence, whereas sequences obtained entirely within the Brassicaceae have been found to have too little divergence . Three of the remaining species had complete genomic sequences, while the other two consisted of two contigs separated by a gap of unknown size. In the B. rapa ortholog, the gap was located in the 3’ region, and was flanked by 256 and 452 base pair sequences that did not align with any of the other Brasssicaceae orthologs, despite strong sequence conservation in the surrounding regions. This indicates the recent insertion of a large DNA fragment, potentially >700bp in size. Attempts to locate the source of the two end-fragment sequences in the B. rapa genome with BLAST searches, unexpectedly found that each was present in multiple copies, and were distributed across several different chromosomes. No evidence of transposable element sequences were found, so the flanking regions were here interpreted to be contaminating scaffold sequences from the original genome assembly. A similar gap of unknown size occurred in C. grandiflora, where one contig aligned with the CDS and 3’ UTR, while the entire 5’ upstream contig failed to align with any other ortholog. In both cases, the non-aligning sequences were removed from the analysis, providing a final alignment consisting of four orthologs in the 5’ promoter region, and five orthologs spanning the CDS and 3’ UTR. Overall, the five orthologs shared between 27% and 65% sequence similarity, and grouped into two closely related pairs. One pair contained C. grandiflora and C. sativa, and the other contained A. thaliana and A. lyrata. In contrast, B. rapa was found to be distinct from all other Brassicaceae orthologs, which accurately recapitulates its predicted evolutionary relationship with the rest of the family. Upon closer inspection, the coding regions were found to be 79-93% similar, which dropped to just 14-34% in regions with no significant alignments. The initial alignment was considerably fragmented, with many insertions, deletions, and isolated nucleotides. In many cases, the position of these features varied with the settings in the alignment software, and were here interpreted to be artifacts of the alignment procedure.

To correct such artifacts, isolated nucleotides were manually adjusted left or right to maximize local sequence alignments within ±5bp. Where variation in the length of tandem repeats was apparent, gaps were introduced into one or more ortholog sequences to accommodate the largest number of repeats present. Conserved regions were then identified by using a 5bp sliding window to identify regions with more than 60% identity. This window is unusually small compared to previous studies that have used 15-50bp sliding windows, but was chosen here to more accurately reflect the minimum size of known transcription factor binding sites. Where large contiguous conserved regions were found, the presence of small 1-3bp indels within their sequences were used to break them into smaller fragments, as disruption of these sites indicates that they do not contain functional cis-motifs. scattered in the 3’ UTR. Several predicted transcription factor sites were found within the coding regions, but these were interpreted to be non-functional, as previous GUS-reporter systems did not reveal any significant regulatory elements within this region. Among other notable features was a predicted signal peptide in the first exon, identified with signal P 4.0,blueberry pot which was almost entirely conserved and is consistent with the secretion of the mature CLV3 oligopeptide. In addition, the second exon was found to be completely conserved with no In all, 42 conserved regions were identified, ranging in size from 5 to over 111bp long. Fourteen footprints were found in the coding sequence, of which nine of were clustered around the three exons. Only one footprint was found entirely within in the 5’ UTR, and the remaining four were intervening gaps. The second exon also completely overlapped with several predicted transcription factors, including HOX2a, aswell as cytokinin and gibberellic acid responsive motifs. This suggests as-yet unrecognized functional role for the second exon, which might explain why it has been retained in a family that consists largely of single exon genes. The 3rd exon was also highly conserved, although curiously the most conserved region only partially overlapped with the CLE motif and instead included part of the C-terminal extension. In the 3’ UTR, the footprints were found to overlap with potential zinc-finger and MYB binding sites, as well as a cytokinin responsive ARR10 site. In the upstream regulatory region, the 5’ promoter contained ten conserved footprints, eight of which formed a large and nearly contiguous block near the TSS. The two isolated footprints were located at -204bp and -167bp upstream, corresponding to the palindromic Motif#2 and the redundantly predicted MYB binding site, respectively. In the remaining footprints, additional predictions were found for an overlapping AGL15/CBF site, an auxin response element, overlapping GT1 and AGAMOUS sites, and one prediction for a TATA-less promoter. The latter may be related to the position of the only recognizable TATA box-like sequence, which at – 68bp upstream, which is more than double the usual 25-35bp described for other TATA-based promoters. In contrast, the 3’ enhancer region contained seventeen footprints arranged in roughly three clusters, spanning a region nearly 600 bp long. Two of these clusters closely corresponded with the previously noted clusters of predicted transcription factor sites, while the third was distinctly isolated and had no predicted transcription factors. Together, the footprints contained one of the three known WUS binding sites , two predicted AtHB1 binding sites, a cytokinin responsive element , several bZIP motifs, a KNOX-like site, and a predicted cis-motif forNPR1. Strikingly, the majority of the footprints also overlapped with a DNA transposable element in A. thaliana, At2TE50665 . It has previously been implied that WUS controls CLV3 expression in a concentration dependent manner, which is consistent with the close proximity of two demonstrated WUS binding sites .

The region around these two sites also contains several other TAAT cores within a single stretch about 100bp long, much of which is represented by four conserved footprints, which together might form a WUS binding site cluster. However, only the +970 WUS binding site was found to be perfectly conserved, while the other TAAT cores displayed mutations or were interrupted by indel sequences in one or more orthologs. Instead, when the region around the known WUS binding sites was examined in more detail with a 5bp sliding window, a strikingly periodic pattern was observed, where four different conserved motifs were found to be regularly spaced about 15 bp apart. In order from 5’-3’, these motifs were identified as CCGTTGGG, AGTAC, TTGTCAA, and TAATTAATGG , the latter two of which correspond to a predicted W-box motif, and the +970 WUS binding site. In addition, a perfectly conserved sequence was found just 25-36 bp downstream in all orthologs, which consisted almost entirely of tandem repeats containing ATG. The ATG repeats also overlapped with a predicted ALFIN-1 homeodomain/Opaque-2 binding site, suggesting that this sequence may actually represent a modified bZIP motif, or perhaps an atypical homeodomain binding site containing a TGAT core motif. It is not clear how many potential binding sites are present in these ATG repeats, but in consideration of the size of the conserved region, it seems likely that they could accommodate up to three transcription factor proteins simultaneously.The potential functional role of the TGAT motifs is further supported by the observation that they are 4x over-represented in the surrounding 124 bp conserved region, while the TAAT cores actually are 5x under-represented. In addition, pair-wise distance measurements between the two cores revealed a skewed distribution, where few sites were found closer together than the median value of 5bp. When several median-length pairs were aligned, this corresponded to the 13bp motif TAATnnWnnTGAT. When this motif was subjected to Patmatch searches of the A. thaliana genome, it was found to be 26x over represented among the genes directly targeted by WUS. Multiple copies of the 13bp motif were also found in several target genes, including two in the 3’ enhancer of AtCLV3.

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The subsistence technology type that has probably sparked the most controversy is hunter-gatherers

Imagine that an STI which leads to infertility occurs in the female population with probability k. Then, an uninfected man and his wives can avoid infertility if and only if none of his wives have the infection. This occurs with probability: n . If we assume an empirically plausible rate for this STI, like 0.07 , then a monogamous man would be paired with fertile woman 0.93 of the time, and a man in 2-polygyny would be paired with fertile women 0.86 of the time. An ultra-wealthy man in 10-polygyny, however, would be more likely than not to have infertile wives—a prospect that could lead to diminishing fitness returns to, and hence, demand for, additional wives. A similar argument holds even if marriage is considered sequentially—as in serial monogamy—though the effect would be smaller. Finally, impediments to cooperation or even outright conflict among co-wives can be greater as the number of wives increases. Interference competition among co-wives could impose significant fitness costs in settings where effective child rearing benefits from cooperation. It could well be that incumbent wives resist incorporation of additional wives to the wealth sharing pool, perhaps with greater effectiveness as their numbers grow. Empirically exploring these and other possible explanations for the unexpectedly substantial diminishing fitness returns to additional wives that are not explainable by the division of rival wealth among wives would be a valuable next step, but one that would take us beyond the formal modelling, database and comparative statistical methods that we have presented.Recent anthropological research on the causes of war falls roughly into two schools : one which concludes that sociopolitical factors are the primary determinants of war ,large plastic pots and another which argues that environmental and technological factors are primary . Both “schools” have developed testable hypotheses about the conditions making a society more likely to go to war .

In this study we retest two hypotheses initially tested by Nolan : first, more productive subsistence technology leads to more war; and second, higher population density leads to more war. Both hypotheses come from ecological-evolutionary theory, which asserts that subsistence technology is the single most important factor affecting how societies are organized and how they interact with one another . Ecological evolutionary theory predicts warfare is more frequent in societies with more productive subsistence technology for three main reasons. First, armies need to eat; a society with unproductive subsistence technology would not have the food stock to sustain soldiers in a prolonged conflict. Second, food stores make for attractive targets; hence, societies with more productive subsistence technology are more likely to be attacked. And third, fixed investments in fields and structures give a society with more productive subsistence technology a strong incentive to defend its territory from attackers.Some have claimed that, compared to other societies, hunter-gatherers are relatively peaceful while others disagree . Ecological-evolutionary theorists tend towards the ‘relatively peaceful’ side of the debate. Nolan , for example, argues that hunter-gatherers usually lack the resources to sustain them during long periods of warfare. Likewise, they have little to be plundered and find it feasible to walk away from a confrontation and move to a new area. Ecological-evolutionary theorists expect the frequency of warfare to be higher among horticulturalists than among hunter-gatherers. Horticulturalists own more resources than hunting-gathering societies, and are more attractive targets. While hunter gatherers can with relative ease walk away from an attack and move to a new location , horticulturalists are more likely to defend their lands and structures . And since metal tools make horticulturalists more productive, and metal weapons make warriors more deadly, horticulturalists are expected to have even higher rates of warfare if they have learned to use metal .

Slavery has a similar effect in increasing the frequency of war: armies can capture slaves, which can then be used to produce food, which can be used to feed armies, which can then capture more slaves – thus creating a positive feedback warfare-slavery system . Ecological-evolutionary theorists expect plow agriculturalists to have even higher frequencies of external warfare than horticulturalists , since they have more productive subsistence technology, which compounds the warfare incentives affecting horticulturalists. Agrarians are even more reliant on their land than horticulturalists and therefore even less likely to walk away from a confrontation; they can produce even larger and more diverse food stores – further incentivizing plunderers; their larger food stores can feed larger armies; and slavery becomes even more profitable as more productive technology increases the returns to labor. For these reasons, most previous studies of the ecological-evolutionary theory of warfare have supported the idea that as subsistence technology becomes more productive, the frequency of warfare increases. The hypothesis of a positive correlation between population density and warfare is based upon the notion that, within a given subsistence technology type, increases in population density will increase the pressure on a society’s resources, thus motivating a society to plunder the resources and conqueror the arable lands of its neighbors. Hence, some studies maintain that the frequency of warfare will increase as population density increases. Other studies argue for a cubic relationship – claiming that warfare increases, decreases, and finally increases again across categories of increasing population density. In his study of precontact Polynesia, Younger finds a negative relationship between population density and violence. Thus, there is by no means a consensus within the literature about this relationship. In a 2003 paper published in Sociological Theory, Patrick D. Nolan sets out to test whether certain modes of subsistence are “structurally conducive” to warfare . Using variables from the Standard Cross-Cultural Sample , Nolan produces a number of contingency tables, examining whether the frequency of warfare varies across four subsistence modes and by population density.

He finds that societies with advanced horticulture or agrarian subsistence engage in warfare much more frequently than those with foraging or simple horticulture. He also finds that high population densities are associated with more war in societies with foraging or agrarian subsistence, but not in those with horticulture. While we find much of value in Nolan’s theoretical discussion, there are serious problems with his empirical analysis. First, in adopting a contingency table approach, Nolan chooses a method that requires reducing the variation found in the original SCCS variables, in order to have relatively few cells in each table. Thus he takes a measure of frequency of warfare , available in the SCCS with 18 discrete values, and turns it into a dummy variable, with only two discrete values. Likewise, he employs only four general subsistence categories, a feat he manages by lumping hunting with gathering, and discarding 54 of the 186 SCCS societies that subsist as mounted hunters, fishers, pastoralists, or rely equally on two or more subsistence modes . Particularly problematic is the removal of relatively warlike pastoralists and mounted hunters from his sample. Table 1 compares Nolan’s categories with the categories given in SCCS v858. The four subsistence taxonomies presented in the SCCS provide much richer detail: variable v246 has seven categories; variable v833 has eight; variable v858 has 11; and combining variables v833and v834gives 28 categories. But even more variation can be found by using variables v814–v819, which provide actual ordinal measures of the percentage dependence on each category of agriculture, domestic animals, fishing, hunting, gathering, and trade. Variation is the great friend of any statistical analysis, and the SCCS contains variables that provide abundant variation on subsistence technology. That Nolan reformulates his variables to reduce variation is due simply to his choice of technique— contingency tables work well only when there are relatively few cells in the table. Contingency tables also limit the analysis to pairwise relationships between variables, and at best can be modified to fit a three-way relationship. When there are confounding variables, as there always are,plastic pots for plants the results from a pairwise analysis will be biased. It is on this count that multivariate models provide their greatest advantage: one can control for the effects of other variables and thus produce unbiased estimates. And because multivariate methods consider a large set of variables, one can gain a sense of how important a particular relationship is in the grander scheme of things. Galton’s problem—the confounding effect of cultural transmission—is a major methodological issue in empirical studies using cross-cultural survey data. There are no effective ways to control for Galton’s problem within a contingency table framework and Nolan wisely does not try. Dow has developed an effective way of modeling Galton’s problem within a multivariate model framework, which provides yet another advantage to multivariate methods over contingency tables. Finally, there is the problem of missing data. As shown by Dow and Eff , dropping observations for which data values are missing can lead to bias, even within a multivariate modeling context. Nolan dropped observations that were not even missing—removing 54 societies that did not fit neatly into his subsistence taxonomy categories .

The appropriate way to handle missing data is the technique of multiple imputation . Nolan’s empirical work does not do justice to his theoretical discussion. In what follows, we investigate the role of subsistence technology and population density in causing war, using contemporary best-practice statistical methods. Wealth accumulation provides the means for elites to enhance their status, and this status-enhancement strategy is both an alternative to the strategy of war and can be disrupted by war, making war less attractive to elites. SCCS variable v17 was included as a scale for the use of money and credit. Small communities are less likely to have powerful elites , and are therefore less likely to be driven by elites to war. In fact, Younger’s study of Polynesian war found that smaller communities were more peaceful. We therefore include a scale for community size . Elites will also be less able to drive a society to external war when their power is less secure; variable v575 was included as an “unstable political power index.” If local political structures are complex, elite power may be fragmented, and it may be difficult for all relevant actors to agree upon a course of action, which would make war less frequent. For this reason, v236, a measure of the number of levels in the jurisdictional hierarchy of the local community, is included. Similarly, we introduce variable v757, which measures whether political authority is simultaneously religious authority, reasoning that more heterogeneous elites are less likely to find common cause in external war. Military historians speak of the three “C’s” in the analysis of war: causes, conduct, and consequences . Our analysis focuses on the causes of war, but features of a society facilitating its conduct will also serve to make a society more likely to go to war, and in this way the feature can be seen as a cause. For example, when females contribute a great deal to subsistence, the opportunity cost of sending a man to war is lower, and the choice of war therefore is less costly. For this reason, we include variable v826, “average female contribution to subsistence.” Certain kinds of technology facilitate the conduct of war. For example, the development of metal weapons makes warfare more practicable and increases its incidence . Thus, we create the variable metal as the composite for four SCCS variables concerning the use of metal tools and weapons.4 Similarly, Nolan notes that limited communications and transportation technology “were the only real constraints” horticulturalists faced in using war to control more land and subject peoples. We employ here v149, which measures the degree to which a society utilizes writing and records. A prior study by Brown and Eff found the frequency of external warfare and the presence of moralizing gods to be inversely related; suggesting that morality reinforced by supernatural forces may serve to constrain warlike behavior. We investigate this by including SCCS variable v238 in our model. The bottom panel in Figure 3 plots the total effect on the ordinate and pdens on the abscissa. Since pdens is standardized, the total effect will be positive for societies with below-mean population density, and negative for societies with above-mean population density. The resulting plot is nearly linear—fitting a negatively sloped straight line with an R 2 of 0.796. Our model’s negative relationship between population density and the frequency of war is consistent with Younger’s findings but not those of Nolan or Keeley .

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Fruit were harvested from healthy and HLBaffected trees

Volatiles that signal the presence of flush may be important components in scent lures. Flushing shoots are essential for ACP reproduction. Signature odors might include cuticular hydrocarbons, ammonia, methanol, and carbon dioxide, all of which are emitted during leaf expansion. These compounds may synergize ACP response to terpenes emitted by foliar scent glands. Sesquiterpenes may be important signal compounds. These terpenes are prevalent in the aromas of ‘super hosts’ but most are commercially unobtainable; little is known about their effect on psyllid attraction. A better understanding of these factors could lead to the development of scent lures that are consistently effective in a variety of application situations. Better monitoring tools would especially be useful where ACP population densities are low or for tracking psyllid movement patterns. Citrus groves receiving nutritional sprays to manage HLB were compared with groves in the same areas receiving conventional fertilization treatments.In 2009–2012, HLB fruit were sorted into symptomatic and asymptomatic , while later , no distinction was made between symptomatic and asymptomatic HLB fruit. Fruit were washed and juiced using JBT extractors and finishers, then pasteurized following industry standards. Sensory tests were performed with trained and untrained panelists. In 2009–2010, differences between juice from healthy and HLBa fruit were minimal, and only perceived by trained panelists. Juice from HLBs was off-flavored, bitter, sour, with some metallic, tingling, and umami taste. These descriptors were mostly used for early season Hamlin,macetas 5 litros while the effect of HLB on Valencia juice flavor was minimal. Nutritional treatments had no consistent effects on juice flavor over the 5-year duration of the study.

Difference-from-control tests showed improvements due to nutritional treatments on Hamlin in January 2012, December 2012, and January 2013, i.e., panelists could not detect differences between juice from healthy and HLB fruit. Trained panelists found more differences between juice from healthy and HLB fruit than between juice from different nutritional treatments, except for one Hamlin nutritional juice in December 2012. Blends made with 75:25, 50:50, and 25:75 ratio of healthy and HLB Hamlin juice were also tested. Trained panelists classified the 75:25 blend with healthy juice, and 25:75 with HLB juice, confirming previous blending studies, while the flavor of the 50:50 blend varied with harvest. In conclusion, no management practice in the field was able to alleviate the effect of HLB on juice flavor. However, much of the off-flavor depended on the season and levels of sugars, acids, and other components in the juice. The Asian citrus psyllid was detected in California in October 2008 and has invaded most of the citrus grown in southern California. Huanglongbing was detected in Los Angeles County in 2012 and poses a significant threat to California’s ~$2 billion citrus industry. Establishment of ACP and HLB can cause huge economic loss and it is important to slow the spread of the HLB pathogen. At present, this can best be achieved by controlling the size and spread of psyllid population through integrated management strategies. A series of lab trials were conducted to evaluate the residual efficacy of various conventional and organic chemicals for ACP control and for selection of chemicals that were least toxic to natural enemies like Tamarixia radiata. The most persistent organic insecticide tested was Entrust + oil and to a lesser extent Trilogy. Among four pyrethroids, Danitol was most effective and persistent, while Mustang was weaker when tested with adult ACP. However, when toxicity was tested with adult Tamarixia, both the organic and conventional pesticides were not as toxic as they were to ACP adults. In a separate study, a field trial was conducted to test the efficacy of organic insecticides against ACP nymphs. Among the materials tested, Entrust + oil provided better control in comparison to two other products.

Future plans include further trials under lab and field conditions to evaluate products for ACP control that are least toxic to natural enemies.The Asian citrus psyllid vectors pathogens that cause Huanglongbing or citrus greening disease. Management of ACP is critical in all habitats including organic citrus for area-wide suppression of HLB. Mature citrus trees in Florida go through dormancy in winter producing little or no new growth required for ACP to develop and reproduce. Targeting overwintering ACP adults with sprays of broad-spectrum insecticides has been shown to provide significant reduction into growing season and opportunity for biological control and selective insecticides. This tactic is adopted area-wide in Florida and Texas and also used in California. However, organic farmers struggle with management of ACP and HLB because they cannot use synthetic insecticides. Consequently, we have initiated development of ACP control programs testing use of organic insecticides and release of Tamarixia radiata also suitable for conventional citrus and urban habitats. We evaluated dormant winter sprays of an organic insecticide, Pyganic applied in November, December, and January compared to a single spray of the synthetic pyrethroid Danitol in January against ACP in Valencia and Hamlin oranges. Pyganic was applied either alone, with horticultural mineral oil , or soybean oil at 2% volume by volume. Significant effects of Pyganic plus either oil lasted for 1–2 weeks after November and December applications. Pyganic + HMO and Danitol maintained ACP at or below 0.1 adults per tap sample for 4–5 weeks, and significant suppression lasted 2 months after the January application. Monthly applications of Pyganic with HMO appear to be a reasonable option for organic growers to suppress overwintering ACP. Organic programs evaluating promising insecticides alone or altered with oils or other surfactants are being evaluated parallel to a conventional program. Tamarixia radiata are also being released for integration in these programs. Findings and implications for ACP management will be discussed. Tolerance, or resistance, to citrus Huanglongbing will be important as a long-term solution for this disease. In a field trial conducted with over 1000 plants belonging to different genera in the sub-family Aurantioideae, we observed field tolerance in many Australian citrus relatives. To confirm these results in a controlled greenhouse setting, we have exposed 140 plants to Candidatus Liberibacter asiaticus via psyllid feeding under no-choice conditions for a period of 2 weeks.

We have maintained these seedlings under greenhouse conditions and conducted detailed analysis on the presence of the pathogen and level of tolerance observed in various plants after exposure to the pathogen. We have analyzed the samples using qPCR and droplet digital PCR to estimate the bacterial titer in accessions that were either susceptible, tolerant, or resistant in field studies. To confirm the presence or absence of the pathogen in plants with questionable qPCR results, ddPCR analysis was conducted targeting multiple genomic regions of Candidatus Liberibacter asiaticus. Since these experiments are conducted using open pollinated seeds where the pollen parent is not known, we have also conducted about 2000 pollinations using Microcitrus, Eremocitrus, pummelo, and mandarin as both seed and pollen parents. The targeted crosses were also conducted with known HLB tolerant cultivars of mandarins like Temple tangor and Fallglo mandarin. Citrus greening, also known as Huanglongbing , is a devastating disease on Citrus plants and is caused by the yet unculturable bacterial Candidatus liberibacter spp. This gram-negative bacterium is limited to vascular tissue and mainly accumulates in the symplasm of autotrophic organs. In addition, the accurate quantification of viable bacteria is necessary to assess the status of potentially-infected trees as well as to test any possible control strategies. A number of methods have been broadly described to quantify total bacteria content; which includes the detection of both live and dead bacteria as well as the different bacterial pathovars. In the present work,macetas de 30 litros an improved detection method, based on PCR is described, which employs new designed primers. Real-time PCR was also employed to test the sensitivity of the method, which was able to detect 10 copies per genome in tree-infected trees. In addition, Droplet Digital PCR was also developed to detect two copies per plant genome, which is the highest sensitivity reached in current protocols. The accuracy of the tested techniques will allow assessing the feasibility of possible controlling methods of this devastating disease. Researchers have been exploring more effective ways to control the Asian Citrus Psyllid , the only known insect vector of the phloem-limited bacterium “Candidatus Liberibacter sp.” responsible for Citrus Greening or Huanglongbing disease. Research results are reported on the use of a crowd sourcing challenge-based strategy to identify gene targets in the ACP that can function as interdiction points to control the insect using an oral uptake RNA interference strategy. This challenge was sponsored and developed by the Florida citrus industry and posted on the web through Innocentive, Inc. Interested participants were allowed to submit suggested targets with justifications for orally administered dsRNAs that would be hypothesized to induce mortality by RNAi. Of the sequences submitted, a committee of experts selected 43 for an oral uptake bio-assay performed using an artificial diet screen to identify those that induced mortality. Subsequently, a citrus phloem-limited virus vector was used to engineer citrus to produce candidate dsRNAs in the phloem. When ACP fed on these plants, there was much greater ACP mortality than was observed by artificial diet delivery, in some cases producing 100% adult ACP mortality in detached-leaf bioassays.

RNA Seq analysis shows that resulting ACP transcriptome changes were attributable to genes functionally linked to the gene targeted by RNAi. New methods are needed to control the spread of the citrus greening pathogen, Candidatus Liberibacter asiaticus , by the Asian Citrus Psyllid . This collaborative project funded by the California Citrus Research Board is focused on discovery of protein-protein interactions involved in Huanglongbing transmission. During transmission of CLas within the ACP, interactions between the vector and host regulate how the pathogen moves through the insect, replicates, and is transmitted into a plant. In this study, Protein Interaction Reporter technology has been used to characterize protein interactions between CLas and ACP. The PIR strategy was developed by the Bruce Lab and uses novel crosslinker molecules which covalently link interacting proteins. Mass spectrometric analysis of PIR cross-linked peptides provides information on the relative proximity and orientation of surface exposed lysine residues in cross-linked protein complexes. The Bruce and Cilia labs have previously successfully applied PIR technology to study interactions with an aphid-transmitted virus. Percoll density gradient centrifugation has been applied to purify enriched populations of CLas cells from infected ACP. Using this method, intact CLas cells retaining interactions with ACP tissues are recovered. Infected psyllids were homogenized in a non-denaturing buffer, and the concentrated lysate was applied to a Percoll gradient. Centrifugation resulted in two distinct bands in the Percoll gradient—these fractions were recovered, the cells were washed, and qPCR was used to quantitate the amount of CLas cells present. The PIR cross-linker was used to capture protein interactions in the enriched CLas sample, and the cross-linked peptides were subjected to mass spectrometry analysis. Given the challenges of working with this non-culturable pathogen, this Percoll method for CLas enrichment has a range of potential applications, including the use of purified CLas cells as immunogen for antibody production.Huanglongbing is the most serious recent threat to the US citrus industry. Several studies have indicated that Poncirus is resistant to HLB, but the Poncirus genes for HLB resistance are to be identified and characterized. The Ctv locus in Poncirus confers durable broad-spectrum resistance to citrus tristeza virus , a virus that is phloem-limited like CLas, has been identified and sequenced. We compared the genomic organization of the Ctv region to the corresponding regions from three susceptible citrus species and analyzed the genes, particularly the resistance genes within the locus, in an attempt to gain perspective of the to-be-identified HLB resistance gene in Poncirus. Copy number and localization of R-genes at the Ctv and ctv regions vary considerably from species to species; R-genes have been on faster paces of sequence change than surrounding genes. Dramatic structural rearrangements have occurred, resulting in an expansion of ~60 kb at the Ctv region over the ctv region. While the center of the Ctv region is packed with a rich and diverse group of retrotransposable elements , the ctv regions are free of REs. Pondering these phenomena at Ctv, it is intriguing to speculate the likely structure and evolution of the Poncirus genomic regions harboring HLB resistance genes.Huanglongbing is the most devastating disease of citrus.

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It is less clear what happens when a very similar product is removed from the market for safety reasons

All visible bands were assigned a number based upon relative position to the DNA ladder. Each position was then assigned a “0” or a”1” to indicate absence or presence of the band, respectively. The 0/1 matrix was then used to generate the dendrograms. Similarities based on the Dice coefficient were calculated and UPGMA clustering was obtained using NTSYS software . The comparative cluster analysis of different strains integrates banding pattern data from two separate experiments. The data were combined in a single matrix. Although banding patterns differed there were some band positions in common in some strains across the two studies. The reagents used in the two studies were identical; however the PCR thermal cycler was different, a GeneAmp PCR System 2700 was used in this study. In a previous study 349 strains isolated from different native fermentations in China were screened by interdelta sequence typing. The number of strains tested in this analysis did not allow definitive comparisons of highly similar strains as each strain was only run once. However based on this preliminary analysis 54 different banding patterns were identified. These 54 strains were studied in more detail under conditions enabling conclusive comparisons of DNA band profile. Samples of the strains were run on gels multiple times and band positions calculated in comparison to the DNA ladder on each gel. Strains were run on different gels and yielded identical patterns on the replicate gels. This method generated stable replicate banding patterns for each isolate. The replicated interdelta sequence typing methodology enabled clear differentiation of forty-two distinct S. cerevisiae genotypes among the 54 S. Twenty-one strains of S. cerevisiae isolated from Xinjiang revealed eighteen different patterns . The analysis of thirty-three S. cerevisiae isolates from Ningxia revealed the existence of twenty-four distinct profiles in other words, 24 differentiated strains. The results also showed that the interdelta profile of genotype NX10 was identical to that of commercial yeast Lalvin RC212,maceta 5 litros which has been used in this region as a commercial starter strain.

In general, the Xinjiang and Ningxia regions evaluated in this study exhibited different S. cerevisiae populations. There were no identical strains between the regions. In addition, comparison with the forty-four interdelta genetic patterns found among the fifty-two Saccharomyces strains from Liu et al. revealed that no identical strains were present between the studies. The PCR amplification profiles obtained by interdelta sequence typing were used to obtain independent presence-absence matrices for S. cerevisiae isolates from Xinjiang and Ningxia, China. The dendrograms deduced by interdelta sequence typing are presented in Figures 3 and 4, respectively. The dendrograms demonstrated that native wine fermentations were conducted by a mixture of S. cerevisiae strains. In general a minimum of two interdelta sequence profiles could be detected during each of the spontaneous fermentations with the exception of the fermentation of Big-berry Thompson Seedless. Some strains showed highly similar but not identical banding patterns and are thought to represent genetically related strains. Six clusters of two isolates each, cluster XJ4 and XJ5, XJ12 and XJ15, XJ2 and XJ7 ; NX2 andNX3, NX29 and NX33, and NX9 and NX32 showed highly conserved interdelta sequence patterns indicating that they are likely genetically distinct derivatives of the same strain. Two clusters of four isolates, cluster NX1, NX4, NX5, and NX8; cluster NX17, NX30, NX31, and NX26 also displayed conserved interdelta sequencing patterns again suggesting a genetic relationship among the sets of strains. The S. cerevisiae isolates from Xinjiang that clustered together were from the same grape variety, but, in contrast, the isolates from Ningxia that clustered together were from more than two different grape varieties. NX10 from a native Riesling fermentation was indistinguishable from the commercial strain RC212. A difference was observed in the genetic relationships of S. cerevisiae among strains isolated from table and wine grape varieties planted in Xinjiang . Both table and wine grapes are used for wine production in Xinjiang. Four groups containing nine, eight, three, and one isolate, respectively, were distinguished with a Dice coefficient of 0.448. All nine isolates in group I and all the 3 isolates in group III were obtained from the table grape varieties Red Globe, Small-berry Thompson Seedless, Big-berry Thompson Seedless, and Mixed white . Group II had seven isolates from wine grape varieties of Merlot and Mixed red , and one isolate from the table grape variety Red Globe.

Group IV only included one genotype, XJ3, also from Red Globe . Thus the majority of isolates from the four different table grape fermentations were genetically similar in banding pattern and clustered together. In addition, a difference was observed in the genetic relationships of S. cerevisiae among strains isolated from red and white wine grape varieties planted in Ningxia . Five groups are indicated in Figure 4, when the Dice coefficient is 0.674. Groups I, II, and III consisted of isolates from more than three grapes varieties, while group V only included isolates from Pinot Noir. Group IV included only 1 isolate, NX20, from Cabernet Sauvignon. Most of the S. cerevisiae isolates included in group I were isolated from red grape varieties , while isolates in group III were mainly from white grape varieties . All the isolates in group II were from the red grape varieties of Cabernet Sauvignon, Merlot, and Cinsault . Genetic relatedness was also evaluated by constructing a dendrogram compiled from all interdelta sequence patterns in this study and Liu et al. . Differences were observed in the genetic relationships between the Chinese strains and the strains from the UC Davis collection. The similarity of strains was correlated with their geographical regions of origin: Ningxia strains were closer to the Xinjiang strains, while a clear separation between the indigenous Chinese and the UC Davis strains was observed. The dendrogram produced by interdelta sequence typing revealed five groups containing fifty-one, four, forty-eight, three, and one isolate each when the Dice coefficient is 0.418 . The largest group, group I, contained fifty isolates from China and one from California . There is a difference observed in the genetic relatedness between Xinjiang and Ningxia indigenous S. cerevisiae strains. Group I could be further divided into five subgroups, I-1 to I-5, when the Dice coefficient is 0.506. Most of the S. cerevisiae isolates included in subgroups I-1 and I-5 as well as all three in I-4 were isolated from Xinjiang, while isolates in I-3 and I-2 were mainly from Ningxia . Group II displayed a high similarity with XJ19 , UCD587 , UCD2515 and UCD2516 . Forty-eight out of fifty-two Saccharomyces isolates from the UC Davis collection were clustered in group III. XJ2, XJ7, and XJ20 were clustered in group IV. Group V consisted only of XJ3. Clusters IV and V containing XJ2, XJ7, XJ20, and XJ3 had a low degree of similarity with other Chinese indigenous genotypes and UC Davis collection strains . In addition,cultivo de la frambuesa this dendrogram showed that identical isolates were found only in the same geographic regions with the exception of UCD522 and UCD514 . Understanding the genetic diversity of S. cerevisiae strains from different geographical origins can make an important contribution towards delineating the genetic distance of these strains as well as providing genetic material for further strain development. The genetic diversity of indigenous S. cerevisiae was investigated during the spontaneous fermentations of grape must in Xinjiang and Ningxia, China. Eighteen distinct interdelta profiles were found in Xinjiang, and twenty-four in Ningxia. Forty-two different S. cerevisiae strains were distinguished out of a total of three hundred and forty nine isolates analyzed. All forty-two of these isolates were unique when compared to a set of strains from other major international wine producing regions . Lavin RC212, showing the same interdelta sequence patterns as genotype NX10 isolated from Ningxia was detected during the spontaneous fermentations in this study. Similar to other studies, commercial yeasts were detected in fermentations without inoculation . In this study, the detection of Lavin RC212 colonizing a spontaneous fermentation could be explained by the winery practice of dumping grape skins on the road for drying. Valero et al. analyzed the dissemination and survival of commercial wine yeast in the vineyards near wineries and they suggested that the dispersion of commercial strains is mainly mediated by water run-off and derived from macerated grape skin at dumping sites. Drying the grape skins on the roads for further processing is a normal practice at the Imperial Horse Winery, Qing Tongxia, Ningxia, China, where the spontaneous fermentations were conducted.

It is understandable that this practice could have contributed to the dissemination and survival of Lavin RC212 in the vineyards and wineries, and its occurrence in spontaneous fermentations. In this study, comparison between eighteen and twenty-four different S. cerevisiae patterns by interdelta sequence typing revealed that yeast strains from Xinjiang and Ningxia did not share the same interdelta profiles. The same observations made in the Western Cape, South Africa showed that different S. cerevisiae strains were present at different regions in the different climate zones. In addition, the differences could be attributed to the fact that the grape varieties studied were different in these two regions: table and wine grape varieties in Xinjiang vs. wine grape varieties in Ningxia. This result agrees with a previous study that demonstrated the impact of grape variety on yeast diversity . Further, this study suggests that these two wine making regions are biologically isolated from each other. Geographic location and ecological niches are both thought to play a significant role in Saccharomyces strain diversity . In comparison with strains isolated from other wine making regions, the Ningxia and Xinjiang strains showed a high degree of similarity. This suggests that the indigenous Chinese strains are distinct from European and new world lineages. Nearly identical strains were only found in the wine samples collected in the same viticulture region with the exception of UCD522 and UCD514 . These results are in agreement with previous studies on geographically close regions and widely distant geographic regions . According to Ezeronye and Legras , who studied the genetics of S. cerevisiae strains isolated from palm wine in eastern Nigeria, geographic and/or ecological isolation results in a specific population of S. cerevisiae. These analyses have led to the conclusion that geographic location plays a significant role in genetic divergence. Strain XJ19 displayed a high similarity with UCD587 , UCD2515 and UCD2516 . The relatedness of these four strains may imply a common origin or a commonality of evolutionary forces in the wild. Interestingly as a group the Chinese wine strains appear to show greater overall diversity as compared to the wine isolates from the rest of the world. This is consistent with the narrowness of the Wine European lineage previously described as well as the observations of overall greater diversity of natural S. cerevisiae isolates from China as compared to other regions . The greater natural diversity of isolates of S. cerevisiae from China many represent an untapped genetic reservoir for strain improvement and breeding programs. Knowledge about indigenous yeast strains can also help preserve and employ the most representative strains from a wine region .When making purchasing decisions about products, consumers traditionally include factors such as price, quality, and availability of substitutes.On the one hand, if a product with safety concerns is removed from the market and the remaining products experience additional safety checks, consumers may perceive the market as being at least as safe as before. On the other hand, if the removal of the unsafe product provides negative information about closely related products or the industry as a whole, consumers may respond by decreasing demand, even in the absence of safety concerns about the remaining products. The empirical question is whether a recall of an unsafe product can have a direct impact on consumer purchases and preferences, even if the remaining products are safe. From a safety perspective, the question is relevant if firm incentives to invest in risk reduction and regulatory compliance in existing regulation depend, to some degree, on consumer responses to recalls.In early July 2010, the Center for Disease Control and Prevention identified a nationwide, four-fold abnormal increase in the number of reported Salmonella infections. A month later, on August 13, 2010, a first egg farm, located in Iowa, conducted a nationwide voluntary recall of around 228 million eggs. By August 18, 2010, the same farm expanded its recall to around 152 million additional eggs. Within 48 hours, on August 20, 2010, a second egg farm, also located in Iowa, conducted another nationwide voluntary recall of around 170 million eggs. In total, from August 13 to August 20, 2010, more than 500 million eggs were recalled, in what would be the largest egg recall in U.S. history .

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The second property that affects the flow rate limitation is the distribution of roots

Our second finding is that economic systems in which wealth is more heritable are indeed more unequal, as predicted by our model. For each population and type of wealth, we estimated the Gini coefficient, which is a measure of inequality ranging from 0 to approximately 1. To calculate an overall measure of wealth inequality for a given economic system we again weight the results for each wealth class in that system by its importance . These estimates of overall wealth inequality appear in the last column of Table 2, and in more detail in table S5. They exhibit the same pattern as the transmission coefficients : hunter gatherer and horticultural populations are both relatively egalitarian; pastoral and agricultural societies are characterized by substantial wealth inequality . A third finding is that neither the overall inter generational transmission of wealth nor the level of inequality is greater in horticultural than in hunter-gatherer populations. This result challenges a long-standing view that foragers are uniquely egalitarian among human societies. Thus, it may be ownership rights in land and livestock, rather than the use of domesticated plants and animals per se, that are key to sustaining high levels of inequality. Our finding that macetas plastico cuadradaspastoralists transmit wealth across generations to an extent equal to if not greater than farmers, and likewise display similar Gini coefficients, will also challenge widely held views that herders are relatively egalitarian . Are the relative inter generational mobility of the hunter-gatherer and horticultural systems and the high levels of inter generational wealth transmission of the pastoral and agricultural systems due primarily to technology or to institutions ? To answer this question,maceta 30 litros we take advantage of the fact that both the importance of the wealth classes and degree of inter generational transmission of wealth are similar in the hunter-gatherer and horticultural populations, on the one hand, and the pastoral and agricultural populations on the other. This allows us to reduce the four systems to two.

Forty-five percent of the large and statistically significant difference between the average a-weighted b values of these two groups of economic systems is accounted for by differences in technology, reflected primarily in the greater importance of material wealth in producing the herders’ and farmers’ livelihoods [for the decomposition formula, see section 1; for the paired economic systems results, see table S3]. The remaining 55% is due to differences in institutions, reflected primarily in the lesser degree of transmission of material wealth in the horticultural and hunter-gatherer populations. Thus, although differences across economic systems in both the importance of the wealth classes and in the heritability of a given class of wealth matter, the latter is somewhat more strongly associated with differences in the extent of wealth transmission across generations, and hence the generation of inequality. This is our fourth finding. Note that for the inter generational transmission of wealth, the effects of technology and institutions are complementary rather than simply additive. Econometric analysis shows that this joint effect of material wealth and agricultural or pastoral economic systems in the inter generational transmission of wealth is statistically robust, even when a fixed-effects regression is used to control for all unobserved population-level characteristics . Not surprisingly in light of our fourth finding, additional econometric analysis [described in section 5 of ] shows that both wealth class and economic system significantly and independently predict the level of wealth inequality: material wealth types, and pastoral and agricultural societies, display higher Gini coefficients . Moreover, the greater inequality in material wealth is robust to the inclusion of fixed effects to control for unobservable population level variation . A final finding is that, in the populations studied, the more important forms of wealth are more highly transmitted across generations: The simple correlation between the 43 b values listed in Table 1 and the corresponding population and wealth-class specific a values listed in table S1 is 0.48 .

This is consistent with the view that parents differentially transmit to their offspring the forms of wealth that are most important in that society . This is most striking in the case of material wealth. In pastoral and agricultural societies, its average importance is 0.60 and the average transmission coefficient is 0.61; in hunter-gatherer and horticultural populations, the values, respectively, are 0.18 and 0.13 . Similarly, the less important forms of wealth in agricultural and pastoral systems display significantly lower b values. We implemented two robustness checks to make sure, first, that our results are not driven merely by the qualitative estimates of a provided by the ethnographers and, second, that these estimates are themselves plausible. The first is the above decomposition of the effects of economic system and wealth class, which shows that a substantial difference between economic systems in aggregate wealth transmission across generations would exist even under the unrealistic assumption that the importance of the wealth classes does not differ across economic systems. The second check is provided by our econometric estimates of the importance of material wealth mentioned above. Note that differences between the estimates of the importance of the two non-material types of wealth are modest, and that e + m + r = 1, so we may group embodied and relational wealth, whose importance we measure by 1 – m*, where m* is the average of our econometrically estimated coefficients for material wealth in pastoral , agricultural , and horticultural production. Using these weights, rather than those estimated by the ethnographers, gives results similar to Table 2 [ section 5], but with even greater differences in the inter generational transmission of wealth between the agricultural and pastoral economies, on the one hand, and the hunter-gatherer and horticultural economies, on the other.Our principal conclusion is that there exist substantial differences among economic systems in the inter generational transmission of wealth and that these arise because material wealth is more important in agricultural and pastoral societies and because, in these systems, material wealth is substantially more heritable than embodied and relational wealth.

By way of comparison, the degree of inter generational transmission of wealth in hunter-gatherer and horticultural populations is comparable to the inter generational transmission of earnings in the Nordic social democratic countries —the average b for earnings in Denmark, Sweden, and Norway is 0.18— whereas the agricultural and pastoral societies in our data set are comparable to economies in which inequalities are inherited most strongly across generations, the United States and Italy, where the average b for earnings is 0.43. Concerning wealth inequality, the Gini measure in the hunter-gatherer and horticultural populations is almost exactly the average of the Gini measure of disposable income for Denmark, Norway, and Finland ; the pastoral and agricultural populations are substantially more unequal than the most unequal of the high-income nations, the United States, whose Gini coefficient is 0.37 . Our model explains some seeming anomalies, such as substantial wealth differences in those hunter-gatherer populations whose rich fishing sites can be defended by families or other corporate groups and transmitted across generations and which constitute an atypically important form of material wealth for those societies . Our findings also provide evidence for the view— widely held among historians, archaeologists, and other social scientists—that some influences on inequality are not captured simply by differences in technology, as measured by our a values. For example, the marked hierarchies among some Australian foragers may be due to polygyny , elite possession of ritual knowledge that may be transmitted inter generationally, or even to the dynamics of food sharing . Similarly,macetas cuadradas plastico the fact that some agricultural and pastoral societies do not exhibit substantial levels of economic inequality despite their characteristic forms of wealth being in principle heritable suggests the importance of deliberate egalitarianism, as well as other cultural influences and political choices . Examples include the lavish funeral feasting that redistributes the wealth of the elite among the Tandroy and other cattle pastoralists in Madagascar and elsewhere . Other examples are the Nordic social democratic polities mentioned above. One may speculate on the basis of these results that the current trend toward a knowledge based economy that is less reliant on material wealth and more reliant on embodied and relational wealth might in the long run be associated with a concomitant reduction in inter generational wealth transmission. But the importance in our data set of economic systems per se as a determinant of the dynamics of inequality suggests that the implications for inequality of this shift in how humans make a living will depend critically on our institutions.Walnut is a tree species of great economic importance, particularly in the Central Valley of California , which provides 99% of the US commercial supply and 66% of the worldwide production of walnut kernels . In California, the majority of walnut orchards are located in areas that are periodically affected by drought. In recent years, drought stress has led to increased tree mortality and a decline in walnut productivity across the state . Identifying how plant traits control the supply of water from the soil to the canopy is of high relevance in order to optimize water application while maintaining orchard productivity under increasing climatic variability. Walnut trees have high water requirements. Their growth is strongly affected by water deficit, which results in decreased yield, deep bark canker, and low kernel size and quality, among other issues . In contrast, early seasonal over-irrigation can cause Phytophthora root rot and dieback . In addition, both nitrate  deficit and climate seasonality can alter root-to-shoot growth allocation jeopardizing the sustainability of tree growing operations . As in other parts of the world currently experiencing changes in climate, the increasingly frequent drought events in California call for adjusted water management, which requires understanding of the relationship between water application and tree transpiration to avoid the undesirable effects of limited and excessive irrigation.

The soil water that is available for plants is held by soil matric forces between field capacity and the permanent plant wilting point . This notion has been revised due to the fact that only a fraction of the total available water in the root zone is “readily” available , while another fraction of soil water is available at longer-term. In other words, from a hydrological perspective, plant water availability is “rate limited” by hydraulic impedances on the pathways of water . Three main properties are thought to control the flow rate-limitation. The first one is the soil hydraulic conductivity, which strongly depends on soil water content, texture and structure . The hydraulic conductivity of a drying soil decreases by orders of magnitude, relative to a saturated soil, limiting the water movement from the bulk soil to the soil-root interface .The number of roots in each soil layer defines the length of the pathway , with shorter pathways resulting in higher plant water availability. The third property defining the readily available water is the plant hydraulic conductance . The maximal water flow rate that can be sent to the shoot to supply transpiration is limited by plant hydraulic conductance, which is mainly controlled by root radial conductivity and total root length , though cavitation may limit the axial transfer of water under drought . While root growth affects plant water availability as mentioned above, soil water content can, in turn, affect root growth in many ways. A first feedback is the closure of stomata in conditions of low soil water availability, which limits photosynthesis and thus decreases the amount of carbon available to be invested in root biomass . In tress, the higher root-to-shoot ratios and rooting depth, and the decrease of the biomass of fine roots and root length under water  deficit it’s well documented in field and laboratory experiments . Accordingly, the growth response is strongly influenced by the severity of the stress . Even a considerable amount of the available energy is invested to the growth of new roots, these young roots take up water more efficiently representing a suitable plant strategy under water  deficit . However, other root traits, such as root density, specific root length and root area are only slightly affected . Also, both high and low soil water contents limit root growth; the former through hypoxia and the latter through soil mechanical impedance . Finally, soil water potential and soil temperature appear to be major factors influencing root growth . Otherwise, at canopy level, many plant physiological processes may be related to the control of water status, and the shifting in isotope composition of plant compounds have been related as an interesting plant signaling of water stress, and described as a different approach for measurement of drought impact on the terrestrial ecosystems .

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Producers of containerized plants face several challenges related to water use and runoff

The phase-out of methyl bromide has proven to be a daunting task for the California strawberry industry. Not only are strawberry producers faced with the likelihood that methyl bromide will no longer be available to them by 2015, but they also must deal with increasing regulatory stringency on the use of all soil fumigants. While fumigants face an uncertain future in California, barrier films can help trap fumigants in the soil and reduce the likelihood of environmental or health impacts associated with fumigants in the atmosphere. It appears very likely in the near future that barrier films will be the only type of film approved for use with fumigants in California.Potential methods of strawberry production that do not use fumigants include growing plants in substrates and using steam treatments or anaerobic soil disinfestation. All of these systems are being evaluated on a much larger scale, from 1 to 10 acres, with different soil types, to determine commercial feasibility and cost effectiveness. It is not likely, nor is it desirable from a pest management perspective, that one nonfumigant system will dominate on a large percentage of the strawberry acreage. Multiple production systems, using fumigants and nonfumigants, would allow producers to rotate treatments to suppress soil pests.Increasing global temperatures coupled States . Long with unpredictable changes in climate term drought in California and other regions threaten food security globally . California has experienced United States has caused growers to abandon extreme drought conditions for several years,macetas de plástico fruit crops and seek alternatives with less causing fruit growers to face water limita- water demand in the short term. Options fortions affecting production and leading to mitigating long term drought in California hundreds of millions of dollars in crop rev- have included crop abandonment, stress irenue losses in 2016 alone .

To lessen the impacts of climate new plantings change and increasing temperatures on food and utilization of lower quality secondary security, it is important to utilize diversified water sources. cropping systems to reduce vulnerability to It has been proposed that physiologists and extreme climatic events as experienced in breeders focus on increasing the efficiency California and other regions of the United of water use in agriculture . Improving production efficiency and drought tolerance through cultivar or variety selection has been proposed in tree crops, such as citrus Prunus species , dates , and coffee . Because tree crops can have a considerable amount of variability in terms of physiological traits, it is useful to study diversity in crop species to determine if there are cultivars that use water more efficiently or are able to be productive in stressful conditions. Because pomegranate is a drought tolerant crop, especially once established , it is a candidate crop for growers wishing to switch from more water intensive species, such as avocado, citrus or almond. Pomegranate is a drought tolerant crop that has been grown in California since the Spanish missionaries arrived from Spain and planted mongrel seeds at missions up and down the coast . The pomegranate variety collection located at the United States Department of Agriculture – Agricultural Research Service National Clonal Germplasm Repository, Davis, CA conserves about 200 genotypes of pomegranate sourced from all over the world, many of which have unique phenotypic traits . Experiments have demonstrated differences in morphology and vegetative growth traits, including differences in relative chlorophyll content, plant vigor, and branching habit, which can be observed during propagation and in the field . Although available literature on pomegranate physiology is scarce, research has shown that there can be differences among cultivars for many physiological traits of pomegranate in other collections, including transpiration rate, stomatal conductance, water use efficiency, photosynthetic rate and chlorophyll content . The objectives of this study were 1) to evaluate four unique pomegranate cultivars for physiological field performance in a semi-arid agroecosystem during morning and afternoon hours; and 2) to determine if there are differences among cultivars for physiological traits that would be conducive to commercial crop production in drought conditions.‘Wonderful’ is the industry standard in many countries and was chosen as a control in the experimental cultivar field trial.

The other cultivars were selected for their unique phenotypes. ‘Eversweet’ is a dwarf-like cultivar bred for coastal climates, with pink fruit peel and aril color, and soft seeds. ‘Haku Botan’ is an ornamental Japanese cultivar that has an upright growth habit with double white flowers and darker green foliage than most other pomegranate cultivars and lacks visible anthocyanin pigments in stem, leaves and fruit. The fruit is very acidic and very light yellow in color. ‘Parfianka’ is an internationally-renowned cultivar that has a bright red peel and arils with soft seeds and a balanced sweet-tart flavor. The tree is extremely thorny and has a bushy, highly branched growth habit with smaller leaves than other pomegranate cultivars. ‘Wonderful’ is commercially widely-grown, and in the USA it accounts for approximately 90- 95% of production. It is a highly vigorous, thorny tree that has high yield with red fruit and red seeds with moderate seed hardness and a sweet-tart flavor. The growth habit is willowy, with a tendency to sucker at the base of the tree. Photosynthesis measurements. During fruit development , an infrared gas analyzer was used to measure maximum rates of net CO2 assimilation , stomatal conductance , and transpiration during the morning and afternoon . Morning photosynthetically active radiation ranged from 1500-1600 µmol m-2·s-1 photosynthetic photon flux density , while afternoon PAR was 1990 µmol m-2·s-1 PFD. Morning measurements were pooled for the four cultivars, which occurred on 22, 23 Aug. 2015 and 26 June 2016. Afternoon measurements were taken on 30 June 2016, which was representative of a typical summer afternoon in Riverside . Gas exchange characteristics were measured on two leaves per tree and a minimum of three trees per cultivar. All leaves were collected for leaf area, which was quantified on a leaf area meter to normalize photosynthesis data . Only the most recently fully-formed, sunexposed leaves were selected for this study. Cuvette temperatures were allowed to vary with field conditions. Leaves were measured in a chamber that provided 1500 µmol m-2·s-1 . Instantaneous water-use efficiency was calculated as A·E-1 and intrinsic water use efficiency was calculated as A·gs -1. Stem water potential measurements. Predawn and midday stem water potential measurements were recorded for each data tree. For predawn water potential, non-actively growing shoots were covered with a plastic bag for 10 min before being pruned, placed in a sealed plastic bag and kept in a cooler bag until transferred to an indoor environment for plant moisture stress measurements with a pressure chamber .

For afternoon stem water potential measurements, canopy-shaded nonactively growing shoots were covered with a plastic bag for 10 min before being pruned, placed in a sealed plastic bag and kept in a cooler until immediately transferred to a cool lit, indoor environment. Stem water potential was immediately measured after being removed from the cooler bag. One stem was measured from three individual trees per cultivar, for a total of three trees, for predawn and midday stem water potential. Statistical analysis. All variables were analyzed with Analysis of Variance . When ANOVA indicated significant differences, post-hoc comparisons were performed utilizing Tukey’s honestly significant difference with an experiment-wise type 1 error rate of α = 0.05. Relationships between all variables were analyzed using linear regression , with relationships among parameters determined using general regression with Minitab Software, version 16 . Block was coded as a random effect and interaction terms were included in the models. For the purposes of this work, the R2 value is the proportion of variation in one variable that is explained by the variation in the regressor variable. Regression models were fit to determine differences in slope coefficients and constants among variables. The focus of this review is on water use and water recycling in container-grown production of greenhouse and nursery specialty crops. The majority of information and insights in this review also have applicability to containerized edible crops grown in open air or under protected culture. In container-grown crop production, water application frequency varies from multiple times per day to once every few days depending on the production system, crop producer, growing season, and environmental conditions, such as rainfall. Use of containers has grown in popularity with nursery growers over the past 50 years because crops can be produced more rapidly and economically and the root zone is easier to modify when compared with field production . Ruter showed that total biomass increased by 27% by growing Betula nigra under pot-in-pot conditions compared with above ground container production,cultivo del frambueso which was likely due to more favorable root zone conditions. Container-grown plants also weigh less and therefore are easier to move and ship, allowing more flexibility at an operation and improving shipping efficiency. Containerization allows growers to sell plants throughout the year regardless of soil conditions or plant growth stage, which increases productivity per unit area. Field operations typically apply lower rates of fertilizer and water on a per meter or per hectare basis compared with container production because soil matrices are typically more chemically and water buffered . Field production also has wider plant spacing compared to both container production in nurseries and greenhouses . As inventories are sold, containerized plants can be consolidated to make room for additional plants, while field operations cannot be consolidated. This greater density of ornamental container-grown crop production results in both higher revenue and increased material and input costs compared with field production. Irrigation must be applied more frequently in containerized production systems compared to field soils, because plant available water is lower within containers filled with soilless substrates, which have high porosity and restricted root volumes . Any water, or agrichemicals applied in excess of the capacity of the container, are unable to be utilized by the plant, or fall outside of the container will likely leach and run off and may eventually impact surface water and groundwater .

Concerns persist that as runoff leaves an operation, sediment and agrichemical contaminants will also be exported . Some growers capture and reuse all or a portion of production runoff, whereas other growers allow runoff to drain from their operations to the surrounding ecosystem. Grower hesitation to capture and reuse runoff can usually be attributed to a reluctance to change practices because of concerns about the opportunity cost of lost production area, installation costs of containment and treatment systems, management costs for treatment technology, reintroduction of disease-causing organisms or plant growth regulators, phytotoxicity of reintroduced pesticides, or land characteristic restrictions . In this review, we will discuss these challenges, as well as potential solutions to these issues and limitations Greenhouses are typically characterized as covered or enclosed systems with the capacity to control environmental factors that impact plant growth, including temperature, humidity, irrigation, and light. Operation sizes typically range from a few hundred square meters to 5 ha but can exceed 10 ha. Greenhouse operations tend to be highly intensive production systems on a per unit area basis, but due to smaller container sizes are typically smaller than container-nursery operations. They typically use precise irrigation applications and can have a high degree of environmental monitoring and control. Thus, greenhouse operations typically require less water per unit area than open-air container or pot-in-pot nurseries . This higher degree of control capability can lead to higher distribution uniformity and water use efficiencies. However, efficiencies also depend on irrigation application method , application decisions , and system design and maintenance. The typical higher efficiency irrigation used in greenhouse operations requires higher-quality water and regular maintenance to avoid emitter clogging and subsequent plant loss or damage. Nursery container operations place containers at or below ground level . Plants are grown on various combinations of bare ground, gravel, landscape fabric, or other surfaces that are often graded to reduce standing water directly below containers. Nursery container operation sizes can vary from less than a hectare to thousands of hectares. Irrigation is typically applied overhead using impact sprinkler heads or similar-type heads. Larger containers are often irrigated using micro-irrigation via drip emitters or spray stakes. Although micro-irrigation is more labor intensive to maintain, the necessity of wider plant spacing due to canopy size makes overhead irrigation inefficient due to wind drift and decreased interception efficiency .