Month: October 2024

Three labor-intensive control activities are currently used to reduce SWD-related yield losses: increasing the frequency of harvests, performing field sanitation, and implementing trapping programs to detect the presence of SWD populations. Further compounding these direct labor costs, the productivity of harvesting labor decreases as more frequent harvests and fruit losses due to SWD reduce the availability of marketable fruit to pick. Labor-intensive management activities are more intensely utilized by organic producers due to the lack of efficacious organic chemicals. Increasing the frequency of raspberry harvests means that fruit is harvested sooner, thus reducing the availability of ripe fruit in the field. SWD primarily targets red fruit that is fully ripened or overripe. While SWD also infest fruit before they ripen, this damage is less pervasive. Even if SWD infestations are present in less ripe fruit, the damage is less likely to be visible if the fruit is quickly harvested and cooled. Once fruit enters the cold chain, SWD development slows dramatically. As a result, a common practice among raspberry growers facing SWD damage has been to harvest a day sooner. Prior to the SWD invasion, raspberries were typically harvested every two to six days depending on the time of the season. Decreasing this interval to every one to five days implies a potential 20% to 100% increase in the frequency of harvests due to SWD, depending on the time of the season. Labor-intensive field sanitation efforts, which include pickers removing fallen and damaged fruit, nft growing system is another means of reducing the availability of fruit for SWD to infest. Removal of such unmarketable fruit from the field eliminates one potential source of SWD population growth, though external SWD populations can still be a significant source of damage.

Field sanitation is a recommended practice for all raspberry production even in the absence of SWD, but extensive field sanitation efforts are more likely to be observed with organic producers due to their greater damage rates and the costliness of such activities. Field sanitation is costly because pickers must be compensated. A common practice is to pay pickers a secondary, lower piece-rate for harvesting and disposing damaged fruit. Pickers performing field sanitation have been observed allocating as much as a quarter of their harvesting time to removing unmarketable fruit.26 For example, Rogers, Burkness, and Hutchison 34 examined SWD infestations in Minnesota raspberries and found that the average percentage of unmarketable fruit in untreated open plots was 29%. SWD infestations were found in 81% of sampled berries in these untreated open plots. Similarly, De Ros et al. 28 observed Italian berry growers allocating approximately a labor-hour per hectare each harvest day for sanitation efforts intended to control SWD. Growers who don’t remove fallen and damaged fruit have been observed to sustain increased damage rates as well as a higher probability of rejection of the whole shipment. A final labor-intensive management practice performed by many growers is the construction and maintenance of attractant-based traps. The materials required to produce these traps are inexpensive, but the construction and placement of the traps can be a labor-intensive activity. Growers utilize these traps to detect the presence of significant SWD populations in the fields they manage. However, available traps and attractants are nonspecific and capture many species of vinegar flies. In general, fly captures are a weak predictor of fruit losses. Producers often respond with more frequent insecticide applications and more intensive field sanitation when trap captures indicate the presence of large vinegar fly populations. Overall, the primary benefit of trapping programs has been to alert producers to the presence of SWD in areas where SWD had never been detected before. Regional trapping programs implemented by SWD researchers have also provided a rough measure of adult SWD activity at a given time of the year.

Sampling fruit directly provides a more accurate estimate of damage because virtually all fruit fly infestations in commercially viable California raspberries are SWD. However, direct sampling of fruit for infestations is time consuming for raspberry growers, who must transport their highly perishable product to a shipper within hours of a harvest. It is also a post facto measure since the fruit infestation measured has already occurred, so control at that time is of no value. In addition to growers implementing these labor-intensive SWD management practices, more frequent harvesting and fruit losses due to SWD limit how efficiently a grower can utilize labor. More frequent harvesting and fruit losses reduce fruit density in a field. Workers’ harvesting productivity is negatively impacted when they must spend additional time searching for marketable fruit that is less densely available. The harvest rate per raspberry picker can vary from one to five trays per hour depending on worker skill and fruit availability. An experienced picker can harvest up to 2.5 times more quickly than a novice, and yield alone can cause worker productivity to vary by a factor of two. SWD damage has the potential to reduce raspberry yields by up to 50% over a season and up to 100% in a specific harvest; therefore, it is clear that SWD damage can significantly affect workers’ productivity. Further compounding these labor-utilization issues, growers must offer a higher piecerate when productivity is low in order to retain their labor force and increased variability in available yield for harvest makes it more difficult for managers to allocate labor appropriately. The market for raspberry pickers is highly competitive. Workers who believe they can earn more money elsewhere, because less fruit is damaged, may leave during a harvest or not return for a subsequent harvest. The potential resulting labor shortage in fields with significant SWD damage could further exacerbate fruit losses due to SWD as unharvested fruit become overripe and act as a SWD breeding ground. Further, agricultural labor costs are also rising over time as the supply of labor from Mexico is shrinking due to improving economic conditions. It is difficult to observe these increased labor costs directly, but it is clear that they are not negligible. In 2015, a tray of 12 six ounce clam shells of conventional raspberries sold at an average price of $15.98 per tray based on Salinas-Watsonville and Oxnard district shipping point prices. According to a 2012 UC Davis study of raspberry production costs and returns, production costs were estimated to be $10 per tray of raspberries. Labor costs accounted for approximately half of these production costs, and the study did not report any SWD-targeting activities. The piece-rate alone averaged $4 per tray in a season. If one were to assume, conservatively, that these additional labor costs associated with managing SWD increased total labor costs by as little as 2% and 4% for conventional and organic raspberry producers, respectively, then these activities would account for a 1% and 2% increase in total production costs. Thus, a 1% increase is production costs would reduce a conventional raspberry grower’s profit margin by approximately 1.67%. If a similar cost structure is assumed for organic raspberry producers, then one would expect approximately a 3.34% reduction in profit margin resulting from the additional labor costs associated with managing SWD. Labor costs are assumed to increase by a greater percentage for organic producers because they are more reliant on labor-intensive SWD control methods.SWD’s invasion into North America has significantly harmed the California raspberry industry. We examined revenue losses and management costs associated with this invasive pest. Using a combination of field trial data and expert observations, nft hydroponic system we calculated that SWD has accounted for approximately $39.8 million in revenue losses, equivalent to 2.19% of realized revenues, for the California raspberry industry between 2009 and 2014. Conventional producers accounted for $36.4 million of these losses, equivalent to 2.07% of their realized revenues. Organic producers accounted for $3.43 million of these losses, equivalent to 5.74% of their realized revenues. SWD management activities have also significantly increased production costs for raspberry growers. We calculated that the cost of chemical purchases increased annual per hectare production costs for conventional and organic producers by $1,161.28 and $2,933.01, respectively. We also calculated that the cost of labor-intensive SWD management activities decreased conventional and organic raspberry producers’ profits by 1.67% and 3.34%, respectively.

Even though the industry has managed to adapt to the pest, these revenue losses and management costs have significantly reduced the profitability of the commercial production of fresh raspberries. Looking into the future, it is unclear whether SWD will remain a threat to California’s raspberry producers. On one hand, the primary biological reason that SWD has become such an economically damaging pest in both North America and Europe following its invasion is the absence of an effective natural enemy. In Asia, where SWD originates, the presence of effective natural enemies greatly reduces damages associated with the pest. Thus, the introduction of an effective biological control agent could dramatically reduce these estimated losses in the future. On the other hand, California’s raspberry producers rely heavily on chemical management options to reduce yield losses associated with SWD infestations. If SWD populations were to develop significant resistance to these chemicals over time or restrictions were placed on their use, then these estimated losses could increase dramatically. Agriculture is a key human activity in terms of food production, economic importance and impact on the global carbon cycle. As the human population heads toward 9 billion or beyond by 2050, there is an acute need to balance agricultural output with its impact on the environment, especially in terms of greenhouse gas production. An evolving set of tools, approaches and metrics are being employed under the term “climate smart agriculture” to help—from small and industrial scale growers to local and national policy setters—develop techniques at all levels and find solutions that strike that production-environment balance and promote various ecosystem services. California epitomizes the agriculture-climate challenge, as well as its opportunities. As the United States’ largest agricultural producing state agriculture also accounted for approximately 8% of California’s greenhouse gas emissions statewide for the period 2000–2013. At the same time, California is at the forefront of innovative approaches to CSA . Given the state’s Mediterranean climate, part of an integrated CSA strategy will likely include perennial crops, such as winegrapes, that have a high market value and store C long term in woody biomass. Economically, wine production and retail represents an important contribution to California’s economy, generating $61.5 billion in annual economic impact. In terms of land use, 230,000 ha in California are managed for wine production, with 4.2 million tons of winegrapes harvested annually with an approximate $3.2 billion farm gate value. This high level of production has come with some environmental costs, however, with degradation of native habitats, impacts to wildlife, and over abstraction of water resources. Although many economic and environmental impacts of wine production systems are actively being quantified, and while there is increasing scientific interest in the carbon footprint of vineyard management activities, efforts to quantify C capture and storage in annual and perennial biomass remain less well-examined. Studies from Mediterranean climates have focused mostly on C cycle processes in annual agroecosystems or natural systems. Related studies have investigated sources of GHGs, on-site energy balance, water use and potential impacts of climate change on productivity and the distribution of grape production. The perennial nature and extent of vineyard agroecosystems have brought increasing interest from growers and the public sector to reduce the GHG footprint associated with wine production. The ongoing development of carbon accounting protocols within the international wine industry reflects the increased attention that industry and consumers are putting on GHG emissions and offsets. In principle, an easy-to-use, wine industry specific, GHG protocol would measure the carbon footprints of winery and vineyard operations of all sizes. However, such footprint assessment protocols remain poorly parameterized, especially those requiring time-consuming empirical methods. Data collected from the field, such as vine biomass, cover crop biomass, and soil carbon storage capacity are difficult to obtain and remain sparse, and thus limit the further development of carbon accounting in the wine sector. Simple yet accurate methods are needed to allow vineyard managers to measure C stocks in situ and thereby better parameterize carbon accounting protocols. Not only would removing this data bottleneck encourage broader participation in such activities, it would also provide a reliable means to reward climate smart agriculture.

The spatially-explicit nature of the model allows for robust representation of varying canopy architectures and their effect on berry temperature. The objective of this study was to accurately simulate the spatial and temporal grape berry temperature fluctuations from different vineyard designs, such that model predictions are robust to changes in vineyard configuration such as row spacing, trellis system, and row orientation.The 3D geometry of the ground, woody tissues, leaves, and grape berries were represented using a mesh of triangular and rectangular elements within the Helios 3D modeling framework. The procedural plant model generator in Helios allows the user to specify average and random geometric parameter values in order to create a given canopy geometry. Grape berries were represented in 3D as tessellated spheres composed of triangular elements, the ground surface was represented as a planar grid of rectangular elements, woody tissues were represented as a cylindrical mesh of triangular elements, and leaves were represented as a planar rectangle that is masked to the shape of a leaf using the transparency channel of a PNG image.When the terrain was flat, only one grapevine plant geometry was represented in the model, but with periodic boundary conditions applied in the horizontal directions which effectively yielded a horizontally infinite canopy. For inclined terrain, 7 rows of grapevine plants were represented in the slope-normal direction, and periodic boundary conditions were enforced in the slope-parallel direction .For triangular elements corresponding to grape berries, it was assumed that, large round pot since the density of lenticels after veraison is low, the latent heat flux was negligible.

In terms of Eq. 3.1, this assumption was implemented by setting gw = 0 for berry elements. It was also assumed that heat released from metabolic activity within the fruit is negligible, and thus no metabolic heat source term was included in Eq. 3.1. The formulation given by Eq. 3.1 also inherently assumes that the surface temperature at any point is representative of the entire temperature of the object . Furthermore, since the surface of the berry is discretized into many triangular elements that could have different temperatures, it was effectively assumed that each triangle corresponds to a “slice” of berry volume subtended by the triangle, which is at the same temperature of that triangular surface element, and responds to ambient changes with a time constant equal to that of the entire berry . Average berry element radiative properties for PAR and NIR bands are given in Table 3.1, which were measured for 3 replicates in the field . For rectangular elements comprising the ground surface, Eq. 3.1 was applied without the latent heat term , thus assuming that latent cooling due to water evaporation from the soil was minimal. The heat storage term in Eq. 3.1 was retained and used an assumed value of CprA of 30 kJ K−1 m−2. Clearly, the assumption of uniform temperature in the soil column when calculating the heat storage term is incorrect. However, the chosen value of CprA provided a reasonable temperature response time scale for the soil on the order of an hour and gave midday storage values between 20 and 30% of the net radiation flux, which is generally consistent with observations. Furthermore, since the focus of this work was on modeling the temperature of the berries and not the ground specifically, this approximation was deemed acceptable given that the ground temperature only has a secondary effect on modeled berry temperature in terms of long-wave emission.

Note also that convective heat transfer between the ground and berries was not modeled directly, but rather was specified using measured temperature and humidity near the berries.To validate the 3D model, field experiments were conducted in four Vitis vinifera L. cv. Cabernet Sauvignon vineyards from Sept 19th to Oct 10th during the 2018 and ´ 2019 seasons. Two study vineyards were located in Davis, CA and two others were located in Napa, CA , with each vineyard having a different trellis type. At the research site in Davis, the vines were on a flat terrain, and in Napa the vines were terraced along an east facing slope of approximately 30 degrees. The grapevines sampled in Davis were trained to the vertical shoot position trellis system and the Wye trellis system , while the Napa grapevines were trained to a Unilateral cordon and a Goblet system . The Unilateral vineyard was configured with one vine in each terrace level, while for Goblet there were two per level. The sampled vine in Goblet was adjacent to the terrace slope leading upward to the next row. The Napa Unilateral and Goblet grapevines were on the same slope at approximately the same elevation and row orientation. Thus it can be reasonably assumed that these two systems experienced nearly the same ambient conditions, making possible a comparison of the effects of canopy architecture. While the Davis VSP and Wye grapevines were in adjacent blocks with the same orientation, a direct comparison is not possible because measurements were collected in different years, and thus ambient weather conditions were different. For the four experiments, berry temperature was measured using 0.076 mm diameter type ‘E’ thermocouples . The thermocouples were inserted into the center of the berries in exposed clusters facing the east and west side of the vine, and at each side of the vine 4 thermocouples were placed in different berries within the cluster. Because berries could develop necrosis from being punctured by the thermocouple, thermocouples were relocated to adjacent exposed berries at least every 12 days to maintain relatively fresh conditions.In order to remove the effects of canopy-scale energy and momentum transfer and focus only on berry-scale transfer, ambient measurements were made near the clusters and used to force the model.

A weather station was installed at each study site immediately adjacent to the grapevines chosen for temperature measurements. The environmental variable inputs that were measured included incoming above-canopy photosynthetically active solar radiation , wind speed , relative humidity and air temperature . The incoming solar radiation was measured at a height of 3 m and was used to calibrate the incoming solar flux model in Helios as mentioned previously. The wind speed, relative humidity and air temperature were measured directly adjacent to the vine at the cluster height in order to estimate microclimatic conditions just outside of the berry boundary-layer. The sampling period for all weather data was 5 min. Specific humidity was estimated using the measured air temperature and relative humidity data, and since atmospheric pressure was not measured at the site, hourly average air pressure data from the National Oceanic and Atmospheric Administration local weather stations in Davis and Napa. To evaluate the model’s ability to simulate spatial and temporal fluctuations in grape berry temperature, experimental data measured on clear-sky days was used to drive the model and generate predicted berry temperatures. These temperatures were then separately averaged over east-facing and west-facing clusters and compared to average experimental values for the same exposure. The accuracy of the model was evaluated using the statistical error indices of normalized root mean square error , big round plant pot the coefficient of determination , and the index of agreement .An average characterization of weather conditions during the roughly 3-week period in which the weather stations were deployed is provided in Table 3.3. A more detailed graphical depiction of the measured air temperature, air relative humidity, wind speed, and of the calculated specific humidity time series data for the different experimental vineyard designs over the chosen validation period is shown in Fig. 3.2. During the 3-week period, the daily average air temperature was similar in VSP and Wye, with a wider average daily range of temperature in VSP compared to Wye . The daily average and average of maximum and minimum relative humidity were significantly higher in VSP compared to Wye, while the maximum wind speed measured in VSP was similar to Wye. Architectural differences between Wye and VSP were characterized by higher berry height, wider row spacing, and increased self-shading in Wye relative to VSP. Recalling that air temperature, humidity, and wind speed measurements were made at the height of the berry clusters, the higher berry height in Wye likely created daytime conditions of lower convective and radiative heat transfer from the warm ground to the fruiting zone, and overall greater turbulent mixing of warm, moist air out of the canopy. Specifically, during the validation day, the greater wind speed measured in Wye was likely responsible for the reduced air temperature and humidity at the measurement height compared to VSP . For Goblet and Unilateral, during the 3-week period, the daily average and average range of temperature were similar. However, the average maximum relative humidity in Goblet was greater compared to Unilateral and the maximum wind speed was significantly higher in Unilateral compared to Goblet . The architectural differences between Goblet and Unilateral were dominated by the higher berry height and wider row spacing in Unilateral relative to Goblet. Additionally, the close proximity of the Goblet vines to the adjacent terrace slope created an even larger ground view factor. During the validation day, similar to that observed in VSP relative to Wye, the proximity of the clusters to the ground and low wind speeds due to the tight row spacing in Goblet likely contributed to the increased air temperature and humidity fluctuations compared to Unilateral .Spatial and temporal variation in measured and simulated berry temperature is depicted graphically in Figs. 3.3 and 3.4, respectively. A sample visualization of the 3D distribution of the surface-air temperature difference for each vineyard is shown in Fig. 3.1.

During the night, all berry temperatures were near the ambient air temperature, and thus the spatial variability in berry temperature was small and did not vary noticeably among the vineyard designs. During daytime hours, berries in the shade tended to closely match the ambient air temperature, and could reach over 10◦C above ambient when in direct sunlight. The maximum berry temperature increase over air temperature measured in the field was 12.4◦C for VSP, 11.3◦C for Wye, 12.2◦C for Goblet and 14.0◦C for Unilateral . Besides, the closed canopy in Wye that limited berry sun exposure compared to VSP, it is likely that the greater wind speeds in Wye contributed to the enhanced sensible heat flux exchange and thus the reduced temperature as compared with VSP. For the Goblet and Unilateral vineyards, the east-facing slope and the ratio between plant height and plant spacing mainly determined the hours of berry exposure at the different positions, and therefore, the spatial berry temperature fluctuations. High berry temperatures tended to occur in berries in the west side of the vine during the afternoon when air temperature was warmer and there was exposure to direct sunlight . Measurements taken on berries of the west-facing clusters showed that the warmer afternoon temperature increased berry temperature up to 10◦C more than that of a similar east-facing cluster. As shown in Fig. 3.3 the highest temperatures on the west side occurred between 15:00 and 17:00 for VSP and Wye , and between 14:00 and 16:00 for Unilateral and Goblet . It is possible that in Goblet the lower wind speeds, along with proximity of berries to the slope, resulted in less canopy-scale turbulent mixing and a subsequent heating of within-canopy air near the berries compared to Unilateral.Modeled berry temperatures fluctuated rapidly with changes in absorbed radiation, sensible heat, and heat storage. Maximum values of simulated cluster absorbed radiation for the NW-SE orientations in VSP and Wye occurred about 3 hours before noon in the east side of the vine and 4 hours after noon in the west side . Horizontal canopy division in Wye increased self shading early and late in the day compared to VSP, which minimized exposure to direct sunlight. The widely spaced vines and high berry height in Unilateral favored greater berry light interception early in the morning compared to Goblet. In Goblet and Unilateral vineyard systems, the large difference in bunch exposure between the east and west side of the vines appeared to be dominated by the east-facing slope, which reduced the absorbed radiation in the west side of the vines compared to the east side. Vineyard geometry had a significant impact on the timing of cluster shading, primarily because of variation in row spacing relative to the plant height. While the absorbed radiation fluxes were positive during the day, the sensible heat fluxes tended to be negative during the day because the berries were warmer than the ambient air. Overall, the sensible heat losses were greater in the afternoon due to the greater difference between berry and air temperature during these hours.

The Pancharatnam–Berry phase was discovered by Pancharatnam in studies of polarized light and introduced by Berry as a topological phase for matter wave functions. For light, the Pancharatnam–Berry phase is measured in laser interferometers and exploited in optical elements. Excitons are matter waves that directly transform to photons inheriting their coherence and polarization. This makes excitons a unique interface between matter and light and a unique system for exploring the Pancharatnam–Berry phase for matter waves by light interference experiments. Recent studies led to the discovery of polarization textures in light emission of indirect excitons and exciton–polaritons. This connection of the Pancharatnam–Berry phase to polarization makes it an intrinsic phenomenon for polarization textures. An IX is a bound pair of an electron and a hole confined in spatially separated layers. IXs are realized in coupled quantum well structures. Due to their long lifetimes IXs can cool below the temperature of quantum degeneracy and form a condensate in momentum space. IX condensation is detected by measurement of IX spontaneous coherence with a coherence length much larger than in a classical gas. The large coherence length observed in an IX condensate, reaching ~10 μm, indicates coherent IX transport with suppressed scattering, in agreement with theory. A cold IX gas is realized in the regions of the external ring and localized bright spot rings in the IX emission. These rings form on the boundaries of electron-rich and hole-rich regions created by current through the structure and optical excitation, respectively; see ref. and references therein. An LBS is a stable, well defined, square plastic plant pots and tunable source of cold IXs, thus an ideal system for studying coherence and polarization phenomena.

Different LBS offer IX sources of different strength and spatial extension; furthermore, these parameters can be controlled by optical excitation and voltage. This variability gives the opportunity to measure correlations between coherence and polarization. Here, we explore LBS to uncover the Pancharatnam–Berry phase in a condensate of IXs.The experiment shows that the phase shifts correlate with the polarization pattern of IX emission and onset of IX spontaneous coherence. The correlation between the phase shift and the polarization change identifies the phase as the Pancharatnam–Berry phase acquired in a condensate of IXs. This phenomenon is discussed below. The spatial separation of an electron and a hole in an IX reduces the overlap of the electron and hole wave functions suppressing the spin relaxation mechanism due to electron–hole exchange. In a classical IX gas, spin transport in the studied structure is limited by 1−2 μm due to Dyakonov–Perel spin relaxation. As a result, for uncondensed IXs at r < rcoh, the spin relaxation is fast and coherent spin precession is not observed. However, the suppression of scattering in IX condensate results in the suppression of the Dyakonov–Perel and Elliott–Yafet mechanisms of spin relaxation enabling long-range coherent spin transport in IX condensate. Therefore, IX condensation at r > rcoh dramatically enhances the spin relaxation time leading to coherent spin precession and, in turn, precession of the polarization state of IX emission. This precession generates the evolving Pancharatnam–Berry phase of IXs, which is detected as the shift of interference fringes.

Figure 4d shows that no decay of the evolving Pancharatnam–Berry phase is observed over macroscopic lengths exceeding 10 μm. This indicates the achievement of macroscopic long-range coherent spin transport in the IX condensate.According to current climate projections, we face an increase in the intensity, frequency, and duration of heat waves in the coming years . Therefore, it is imperative that the grape and wine industry study the effects of these heat events on different wine growing regions around the world. Extreme temperatures can have detrimental effects on grapevines including but not limited to decreases in yield, unwanted changes in berry composition, and decreases in overall grape quality . High temperatures cause increased water loss via evapotranspirative cooling and overall stress on grapevines, so irrigation practices can be useful in mitigating the negative impacts of HWs by altering vine water status, leaf and berry temperature. Shade cloths, cover crops, rootstock selection, changes in row orientation and trellis system to protect from solar radiation with misting, or increased irrigation throughout HWs, are further strategies being implemented in current wine regions to mitigate their adverse effects . However, with growing water scarcity, a more efficient use of water and a deeper understanding of the effects of HWs and water use during different grapevine phenological stages will be required . Although grapevines are resilient crops that can tolerate drought and extreme temperatures , it is important to explore alternative grape cultivars that may be better suited for these warmer scenarios. Two widely used irrigation methods are regulated deficit irrigation and partial root-zone drying . In RDI, irrigation is reduced or completely stopped for specific periods during the growing season.

A study done in South Australia showed that water deficit after flowering resulted in the “greatest reduction in berry weight compared with that of well-watered vines” . This is important to note because this may not have been the result had water deficit been practiced before flowering, thus showing that timing is crucial. In turn, water deficit after veraison only had a minor effect on berry weight at maturity and berries were not affected by water deficit during the month before harvest. With PRD, half of the root system is maintained in a dry state while the other half is irrigated . The theory behind PRD is that the watered roots maintain a favorable plant water status, while the dry roots result in chemical signals, such as increases in abscisic acid production, that are transported to leaves to reduce growth and therefore vigor. Deficit irrigation has two main effects on grape berry composition: a decrease in berry size and the upregulation of genes in the phenylpropanoid and flavonoid pathways. In terms of berry size, the skin to pulp ratio increases, which causes phenolic compounds to become more concentrated. In terms of transcriptomics, the upregulation of genes in the phenylpropanoid and flavonoid pathways causes an increase in anthocyanin synthesis due to signaling from an increase in abscisic acid . Alternatively, the effect of deficit irrigation on tannins is largely due to a reduction in berry size rather than an impact on their biosynthesis. . It is important to note that the beneficial aspects of deficit irrigation may not be the same in the future due to projected climate warming, and the combined effects of greater heat and water stress with deficit irrigation may be detrimental to berry quality . Berry development follows a double sigmoidal curve, which is divided into three stages . The first phase occurs after fruit set and is characterized by cell division and cell expansion . This is then followed by a lag phase, which is a period of little to no growth, but is characterized by a rapid accumulation of organic acids, particularly malic acid. The last stage is characterized by the onset of veraison . During this second growth phase, berries soften, accumulate sugar, and grow larger. In red varieties, anthocyanins begin to synthesize, allowing for the red and purple pigments to show in the skins . High temperatures affect berry development primarily at post fruit set, veraison, and mid ripening . A decrease in berry size before veraison caused by high temperatures is due to effects on cell division , whereas post veraison, this decrease is likely due to a stop in cell expansion and an increase in transpiration. Closer to maturity, high temperature seems to be linked to cell death, loss in berry mass, and increased water loss, leading to shriveling and sunburn . With global warming, square pot plastic increasing mean temperatures are further correlated with an earlier onset of phenological stages in the grapevine and the shortening of the duration of these stages . Moreover, since most viticultural regions are currently at or near their optimal growing temperatures for the grape cultivars grown there , global warming intensifies the pressure of exploring new varieties that better suit these regions. Additionally, the effects of HWs on grapevines will depend on the timing of the heat event during specific phenological stages. Although the effects of elevated temperatures throughout the growing season vary by cultivar, literature has consistently shown that flowering is a period that is more sensitive to heat, and the length of the interval from bud burst to flowering is more susceptible to a decrease than other phenological intervals. . During grape development, fruit set shows resistance to elevated temperatures, whereas veraison and mid-ripening are more sensitive to heat . From a berry chemistry perspective, exposure to high temperatures has an important impact on primary and secondary metabolite production in the berry.

Studies have shown that grape berry metabolism is sensitive to both day and nighttime temperatures and the magnitude of these diurnal temperature changes . Primary metabolites of grape berries include sugars, amino acids, and organic acids. While they contribute to the support of normal growth and reproduction, secondary metabolites serve ecological functions, such as defense to abiotic or biotic pressures . Among the secondary metabolites produced by the grapevine, phenolic compounds and aromatic compounds are of major interest due to their impact on grape and wine quality. The Shikimate, phenylpropanoid, and flavonoid pathways are responsible for the biosynthesis of the different phenolic compounds that can be found in grapes . Grape phenolics can be divided into two groups: non-flavonoids and flavonoids. Flavonoids are most relevant to wine quality and are divided into three groups: flavan-3-ols, anthocyanins, and flavonols . Flavan-3-ols are mainly present in the form of proanthocyanidins and contribute to the bitterness and astringency of wine . Anthocyanins are responsible for the color of red wine , and flavonols act as UV protectants and copigments . All three groups of flavonoids are affected by environmental factors including high temperature in different ways. Flavonols are synthesized from the flavonoid biosynthetic pathway and also give rise to anthocyanins and proanthocyanidins . They are primarily located in the skin and mainly function as UV protectants and as copigments with anthocyanins to form stable pigments . The major flavonol compounds found in grapes include quercetin, myricetin, and kaempferol . Flavonol synthesis begins at flowering, reaches peak concentrations after veraison, and decreases during development as the berries increase in size . Flavonol synthesis is light dependent, and sunlight has a greater impact on development than temperature does. While shading has modest effects on berry development, it significantly decreases flavonol synthesis . It has been found that high temperatures don’t have a significant impact on flavonol content when compared to other grape berry metabolites . Gouot et al., studied the combined effects of high temperature duration and intensity on phenolic metabolism of Shiraz berries. They found that flavonol content of berries exposed to 46 °C showed no significant difference to those exposed to 35 °C. However, flavonols were degraded in berries exposed to 54 °C. This shows that high temperature has indirect effects on flavonol levels, while sunlight remains the key influencing factor. Anthocyanins are pigmented molecules responsible for the color of red wines and begin their synthesis in grape berries after veraison, reach maximum values close to maturity, and then decrease . Previous studies have shown that high temperatures affect anthocyanin levels in two ways: inhibiting anthocyanin biosynthesis and promoting degradation . Literature suggests that anthocyanin accumulation in grapes is more influenced by temperature rather than light when photon fluxes are above 100 µmol/m2 /s . Anthocyanins reach critical metabolic temperature for synthesis around 30ºC , but signs of inhibition begin beyond this temperature, where reduction in the activity of enzymes involved in the phenylpropanoid and flavonoid pathways, such as phenylalanine ammonia lyase , VIMYBA2, and UDP-glucose flavonoid-3-O-glucosyltransferase , have been observed . Additionally, it has been found that while anthocyanins were suppressed at transcriptional and enzymatic levels, peroxidase activity had increased, suggesting that peroxidase plays a key role in degradation . Studies carried out in Cabernet Sauvignon by Mori et al., found that biosynthesis of anthocyanins was not affected by high temperatures and the decrease of anthocyanin levels was mainly due to chemical and enzymatic degradation. Flavan-3-ols are the most abundant phenolic compounds in grapes and wine , and they are composed of monomeric catechins and oligomeric or polymeric proanthocyanidins . In terms of sensory effects, proanthocyanidins are responsible for astringency and bitterness perceived in grapes and wine . These compounds also have antioxidant properties and interact with anthocyanins to form stable pigments .

Investments in water-related data and information platforms have the potential for large payoffs by helping entities make more informed decisions. Unfortunately, despite the clear importance for practical decision making, a persistent lack of appropriate water accounting information hinders analysis of likely outcomes of water policy choices. By narrowing crucial information gaps, agencies may improve prospects for agriculture, ecosystems, and underrepresented communities as they confront less reliable and potentially lower overall, water supply allocations in the future . Better and timely monitoring and measurement at the watershed level will also provide a clearer picture of how actions in one part of a watershed may impact other parts of the watershed thereby providing policy makers with a more complete understanding of the consequences and trade-offs of any particular action within the watershed. Universities and other institutions have long supported productivity growth and improved environmental performance of agriculture in California and elsewhere with research and outreach . R&D has contributed improved varieties, irrigation, and drainage technology and improved farm practices that have saved resources and improved environmental outcomes. Progress may come from better integrating social and biophysical sciences for socially just adaptations that value farmers’ knowledge and experience to assist in transitioning to more resilient systems. Developing a coherent research agenda to better integrate climate projections, pest/disease forecasting, soil ecosystems, new genotypes, black plant pots plastic and system designs into agricultural management is needed. More and better organized and documented openaccess water data and models can make further significant contributions to informing policy and decision-making.

The high costs of water transactions, including among farmers, service areas and regions, and for groundwater recharge makes adaptation to climate change more difficult. During 2023, California facilitated some recharge efforts to take advantage of the extreme wet conditions and rebuild groundwater storage. Unfortunately, such measures fell far short of their potential. In addition to infrastructure limitations, permitting delays and other institutional constraints limited the extent of recharge. California’s adaptation to climate extremes would benefit from agile state and local regulation and coordination to facilitate recharge. More integrated water and climate policy will follow from early coordinated and collaborative management and governance to exchange ideas and understand impacts of a wide and inclusive set of scenarios . Careful planning across the policy landscape could foster climate smart policies that leverage current incentives for GHG reductions and offsets to promote adaptation.Like many agricultural regions worldwide, California is facing extreme climate challenges, including increases in water scarcity and water supply variability. Growing competition for water to better support ecosystems and added regulatory oversight will continue to demand innovations to incentivize farms to produce more value with fewer resources. Innovations are often motivated by scarcity and high costs of resources, such as labor, land, and water. Moving forward, more innovation will need to be devoted to reconciling agriculture with ecosystem health, in the context of evolving knowledge and changing climate. External costs and benefits, along with third party impacts, are likely to connect with global food market forces, to drive the direction of agricultural responses. The increased economic, ecological, and community benefits associated with enhanced knowledge of these connections will require significant efforts and commitments on the part of governments and institutions to be realized.

California can enhance climate resilience stewardship by adopting policies and practices to reduce vulnerabilities to climate extremes. Irrigation practices and technology of the recent past, such as those that ignore the importance of groundwater recharge and return flows, and adoption of permanent crops that have minimal year-to-year flexibility in water demand, are increasingly recognized as costly and risky. California is recognizing the value of more flexible water use, both temporally in terms of reservoir storage and carryover rules and spatially in terms of water trading. Moving toward more flexible irrigation water use with smaller negative impacts on rural communities and the environment . Water markets can better direct water to the most valuable social uses by considering third-party impacts water reallocation. Though climate change presents a more variable and uncertain future, it provides opportunities to adapt agricultural landscapes to better steward the environment. Bold measures are urgently needed as water availability limits have already been exceeded and adaptation pathways adequate to address these challenges require faster interventions than current trends . Approaches that decrease exposures to stress, reduce vulnerabilities, and enhance stress resistance and recovery, are important for California to address its climate change challenges. These measures include i) developing a capacity to integrate climate projections, pest/disease forecasting, new genotypes, and system designs into agricultural management, ii) reducing and redistributing irrigation water to recognize the value of ecosystem services, iii) improving prevention, monitoring, and surveillance of droughts and floods, and iv) leveraging GHG reduction and offset policies to promoting biodiversity, and ecosystem resilience. Effective adaptations must go beyond managing the conventionally measured impacts of water variability and toward food systems that address the market and social and ecological drivers . Investing in transdisciplinary research and education to support context-specific adaptations is especially relevant to address the potential social, environmental, and economic tradeoffs.

Building strong and inclusive networks for research, knowledge sharing, and planning is critical to reduce mistakes and scale up the most effective measures that mitigate and adapt to a changing climate.Initiatives to offer more organic, local, or fairly traded foods on the nation’s colleges and universities are spreading throughout the country. These efforts, often called “farm-to-college” or “farm-to-university”, aim to utilize institutional purchasing power to support local growers and principles of sustainable food systems, while providing fresh and healthy food to the campus community. Farm-to-college programs are part of a larger effort to change the food systems in the institutional food service sector, including schools, hospitals, and prisons. Such programs could be a lifeline for small-scale farmers struggling to stay afloat, and would improve the eating habits of millions of Americans. Moreover, if institutional food buyers embrace sustainably produced goods, such as organic or fair-trade products, the environmental and social gains would be significant. The health, economic, and sustainability potential of farm-to-college programs is intertwined with their ability to meet the needs of the campus communities they serve. Knowing the interests and needs of their customers will enable program managers to better gauge “effective demand” and develop programs consonant with the desires of their customer base. To date, while there are a few studies about farm-to-college programs, there has been no research on the preferences and perspectives of campus consumers. Since the success of farm-to-college programs involves their ability to meet the needs of campus consumers, we undertook a study of our local campus, the University of California, Santa Cruz, large plastic pots for plants to learn about the perspectives and preferences of campus food consumers. This research brief reports the results of that study and discusses their implications for the development of farm-to-college programs. The study was conducted in collaboration with groups at UC Santa Cruz working to improve the campus food system. These groups include the UC Santa Cruz Food Systems Working Group, UC Santa Cruz Dining Services, the Community Agroecology Network, and the Students for Sustainability . The questionnaire was developed by Jan Perez, Patricia Allen, and Phil Howard at the UC Santa Cruz Center for Agroecology and Sustainable Food Systems, in consultation with representatives from the groups mentioned above. An online survey was designed to elicit responses on food-related concerns, interests, and level of support for specific food criteria. In addition, questions were included to assess how food concerns rank compared to other national issues, and preferred methods for people to learn about their food. In November 2005, UCSC students, staff and faculty were contacted via email and invited to take the survey online. The survey was available online for people to take until mid January, 2006, and 4 followup emails were sent. There were 36 emails that bounced back, and 464 people completed at least a portion of the survey, resulting in a 25% response rate.UC Santa Cruz is a mid-sized university located on the west coast of California. The campus community tends to be relatively liberal on economic and political issues and enjoys a mild climate that makes possible a diverse supply of fresh fruits and vegetables for most months of the year. Table 1 shows the distribution of respondents in terms of gender , ethnicity , age, and grade level. The table also shows the percentage of students , staff , and faculty who responded to the survey.

These proportions closely approximate those in the campus community: 77% students, 16% staff, and 7% faculty or academic staff. Although food issues are inevitably bundled with general environmental, economic, and social issues, we wanted to get a sense of their importance relative to “non-food” issues, such as strengthening the nation’s economy and terrorism, which have been ranked as top priorities in national opinion polls . Respondents were asked to rank a set of issues on a Likert scale ranging from 4 to 1 . As shown in table 2, food issues were comparatively important to survey respondents. Combining categories of top priority and important, only one issue, protecting the environment, ranked higher than the food issue of access for low-income people . Other important food issues had to do with environment and health—food safety and pesticides in the food system —and working conditions . Food issues that were the least important to respondents were developing local food systems and limiting genetic engineering of foods , which ranked only slightly above protecting the country from terrorism.We also wanted to get a sense of the relative level of interest in specific food system issues to the UCSC community. To gauge this, we asked respondents to rank their level of interest in a series of topics on a scale of 1 to 10 . The topics in which people are most interested are personal—the safety and nutrition of their food, both of which ranked, on average, greater than 8 . Working conditions of workers and environmental impacts of food were of next highest interest, both with an average ranking of 8. Next in line are the wages of workers and the treatment of animals, with an average ranking of 7.71 and 7.65, respectively. This was closely followed by the influence of large corporations . The topic in which people were least interested by a significant margin was the distance food travels from its point of production, at an average ranking of 5.94. Inferences about preferred food qualities can be made from the issues in which respondents are most interested. However, a more direct way of assessing the qualities that people would like to see in their campus food is to determine their level of interest in existing labels that promote different food qualities. We asked respondents to rate their level of interest in purchasing food with the following labels: fair trade, certified organic, locally produced, water quality protection, humane treatment of animals, U.S. grown, and union. The percent of respondents with a “strong interest” in the label , was high, above 50%, for organic, humane treatment, water quality, fair trade, and locally grown . Although the percent with strong interests varies , the differences between the levels of interest in these five labels are not statistically significant. However, interest in U.S. grown and a union label was much lower, and was statistically different than interest in the top five labels. It is perplexing that interest in a union label is significantly lower than in a Fair Trade label, since both deal with providing fair wages and fair working conditions or rules. The negative publicity towards unions in an age where free market principles dominate has likely played a role in these results. In addition, people may have been personally affected by union labor actions such as teacher and bus driver strikes and may have had conflicted reactions as to the merits of such activities. The Fair Trade label, on the other hand, is a relatively new initiative. This newness allows a greater focus on principles and less on the difficult issues that develop when ideals are put into practice. Understanding more about the differential support for unions and fair trade would be worthwhile to explore in future research.

Self-expanding stents are more flexible and restrained within a covering sheath, and by removing the sheath and uncovering the stent; the stent expands. The common materials used to make stents are stainless steel , platinum-iridium, Nitinol, cobalt-based alloys, titanium, and tantalum, along with some biodegradable, bio-resorbable materials such as magnesium and resorbable polymers. Because of anticipated growth in children, self-expandable stents are ideal to be used in children. There are several varieties of stent design that have been used in congenital field, including mesh, coilloop, ring and slotted tube, closed cell, open cell, and welded tube. Here some of the investigation that others did to create an optimum stent is reviewed. Such a stent is not yet available that combines all these requirements, however in this investigation it was tried to address some of these features in the designed stent. Sullivan et al., investigated the effect of the endovascular stent strut geometry on vascular injury, myointimal hyperplasia and restenosis. The authors used a Palmaz stent with rectangular struts and smooth corners and a novel stent with thicker struts and sharper corners to induce larger wall stress concentrations in a 90 days study. Sullivan et al., found that the thicker strut and sharper corners resulted in a statistically higher incidence rate of deep vascular injury compared to the Palmaz stent. As a result, square plant pot a higher restenosis rate observed with thicker and sharp corner struts.

At the end of their study the authors concluded that maintenance of an intact internal elastic lamina is crucial to prevent myointimal hyperplasia and restenosis in stented porcine iliac arteries. Sullivan et al., also found that superficial injury elicits a response that is independent of the stent strut geometry and vessel wall compression. Stent strut profile may, however, increase local vessel wall stress concentrations, leading to IEL rupture and an exaggerated response injury. Therefore, when stents are designed, extra attention should be given to the strut geometry. Bedoya et al., designed some generic stent models that represent the characteristics present commercially available stents. The authors deployed each stent in a homogeneous nonlinear hyperplastic artery model and evaluated them using commercially available finite element analysis software. Using computer simulation modeling Bedoya et al., suggested that stent designs incorporating a large axial strut spacing, blunt corners at bends, and higher amplitudes exposed smaller area of the artery to high stresses, while keeping enough radial force that is enough to keep the lumen open and restore flow. The mentioned articles were reviewed along with several others and they were used to characterize and design the self-expanding stent for this investigation. In this chapter, endovascular stenting and its effect on vascular arteries as well as how to design an optimum stent was reviewed.

A study summarizing the stent grafts that inhibited the growth of the arteries in rapid growing piglets was investigated. Also, clinical studies in children was reviewed and reported that a commercially available self-expanding stent grew with the artery; however, stents migrated in two cases and in other cases these stents caused significant stenosis and obstruction of the lumen in the patients. The effect of the chronic outward force on the lumen of the artery and how over stretching the arteries can cause neointima proliferation was reviewed. In addition, several papers discussing the requirements of a stent for pediatric application as well as how to design an optimum stent that can distribute the force and minimizes the damage to the arterial wall was reviewed. Utilizing all the findings we attempted to design a stent that can grow with small rapid growing arteries and induces the least response. Four potential pediatric self-expanding stent designs with varying numbers of struts, width, thickness, shape, length and architecture were created using Creo Parametric CAD as shown in Figure 1. The crimp profile of each design was simulated using SIMULIA Abaqus FEA software . Through crimp profile simulation, each design underwent iterations by adjusting the number of struts, width, and thickness in order to achieve the following pre-determined traits: crimp profile of < 6Fr, unconstraint diameter of 20mm, and length of 15 to 20mm with a radial force able to withstand vessel recoil after angioplasty. Radio-opacity for visualization under fluoroscopy was also a required but was not simulated.

A stent design with a single row, high amplitude, and low number of struts was selected that could be easily crimped to <6 Fr as indicated by an arrow in Figure 3.1. This design served as the basis for sub-selection of specific candidate stents. All histopathology analysis was performed at CVPath Institute Inc . Before processing for the histology, digital photograph was taken of the vessel and obtained Faxitron digital radiographs in the anterior-posterior and the lateral views. The radiographs demonstrated four nitinol bare metal stents, two measuring 15 mm long and two 20mm long and 10 to 18 mm in greatest diameter for 180 days study and two stents each 15mm length and 12 to 13mm in greatest diameter for 90 days study. An approximate 5 mm non-stented segment was present between the stents. The stents were submitted for embedding in Spurr resin and sectioning by the Exakt method. Proximal, mid, and distal non-stented aortic segments were submitted for paraffin embedding and routine histologic sectioning. To prepare the samples for plastic histology the stented aortic segments were dehydrated in a graded series of ethanol and infiltrated and embedded them in Spurr resin. After polymerization, transverse sections were sawed approximately 4 millimeters in thickness from the stents. Final slides were grounded from each of the plastic blocks to a final thickness of 19 to 90 microns using EXAKT Linear Grinding Technology. Each sample then polished and stained ground sections with hematoxylin and eosin . The mid-section of each stented segment was stained with Trichrome staining. All sections were examined by light microscopy for vessel wall integrity and inflammatory response. Proximal, mid, and distal non-stented aortic segments were submitted for paraffin embedding and routine histologic sectioning. After dehydration in a graded series of ethanol and infiltration with paraffin, the transverse sections for each segment were cut. Each block was sectioned at 4-6 microns and mounted them onto slides and stained with hematoxylin and eosin and Movat’s Pentachrome . All sections were examined by light microscopy for vessel wall integrity and inflammatory response. Representative fabricated self-expanding stents were tested in the radial force tester as explained in the method section and the hysteresis for each stent was generated . The angiographic images were analyzed, and the vessel diameter was measured for each stent prior to the implantation and after the duration of the study as explained in the method section. From the radial force study and the hysteresis results it was possible to find the amount of force exerted on the vessel at the time of implantation as reported in Table 4.1. The growth measurements and the stent chronic outward forces at the time of implantation was plotted in Figure 4.4. A strong correlation between the vessel growth and the stent force was not identified, rather a correlation between the location of the stent and growth and injury was observed. The low force stents in the distal side of the artery grew more than the high force stents in the proximal side. Stenting has emerged as a generally superior option as compared to balloon angioplasty and surgical repair for CoA in infants and children. Nevertheless, square pot the exponential growth of the arteries in children limits the use of stents and requires serial stent redialation and sometimes even fracture or surgical removal. Thus, among pediatric interventional cardiologists, there is a high level of interest in stents that can resorb or grow with the artery. Such stents could eliminate or reduce future reinterventions. This study represents the first effort to evaluate the effects of a purpose-built self-expanding stents on rapidly growing vessels. A range of novel self-expanding nitinol stents were specifically designed and manufactured and used to examine the effects of radial force and stents geometry on the biology of rapidly growing arteries.By varying the geometry and thickness of the nitinol in the stents, four stents with a variety of radial forces were designed, manufactured and tested. The outward force of each stent was measured at each diameter and used to correlate the effects of radial force on biology. These custom-made novel stents easily and reliably crimped and deployed in all the animals with good apposition to the aortic wall.

None of the stents limited arterial growth and there was continuing stent expansion with time, without erosion of the stents completely through the vessels. On average stented vessels grew 14% and 26% more in diameter at 90 and 180 days respectively than the distal and proximal non-stented segments of the vessels, suggesting that the force against the stented artery segments was higher than needed in all cases. The small vessels grew to larger degrees as compared to larger vessels . The experience with these stents suggests that even lower radial force stents may be ideal for this application. There was a favorable neointimal response and no aneurysm was noted in any of the stented vessels. Thus, angiographic results of each implantation universally showed that the stents were able to grow with and beyond the native arteries.Neointimal in growth after use of self-expanding stent has been reported to lead to the narrowing or stenosis of the arterial lumen, thus reducing the luminal area. Compression and tension by the stent struts, wall injury, and peri-strut inflammation due to responses to a foreign body object can cause in-stent stenosis as well as a disruption to the arterial wall leading to long term aneurysms and dissections. All the stents tested in this study formed a mature neointima layer around the stent struts and none had significant luminal stenoses . However, a wide range of damage to the IEL and media was observed: Figure 5.1A shows stent 4 in the iliac artery, with IEL and media laceration. Furthermore, Figure 5.1B shows Stent 4 in the abdominal aorta with compressed but intact IEL and media. All stented segments showed patency without any intraluminal thrombus or obstruction, with ˂20% stenosis in the worst case, despite compression and injuries of the IEL and the medial layer at 90 and 180 days. The long-term effects of the medial lacerations could not be assessed in a six month study. Fortunately, early re-endothelialization was ubiquitous: there was 100% endothelialization of all stents. The radial force of the stents could not be correlated with the stent’s effect on histopathology. No significant correlation was observed between the neointima formation and the forces in the designed stents. Overall injury, and inflammation, value for each stented section were scored according to Schwartz et al.’s scoring scheme . These criteria have been widely used in stent literatures. High injury scores, particularly scores of 2–3, have been reported to yield thicker neointima formation in the porcine coronary arteries. Because the force on each stented artery was a function of both the stent type as well as the diameter of the stented vessel, an attempt was made to correlate radial force with vascular injury and histopathology. While the outward force of the stents did not correlate to biological response, it was noted that smaller arteries in general had higher levels of injury and stenosis regardless of stent force. The mean average injury score was comparable among all stents with higher percent stenosis for stents on the distal side of the abdominal aorta. It is hoped that the data presented in this study will aid in the design of the ideal self expanding pediatric stent. Clearly, this observations in this limited study support the idea that such a device has the potential to improve outcomes in pediatric stenting. Nonetheless, many parameters need to be optimized in designing a pediatric self-expanding stent. This stent needs to have the ability to deploy via a 4-5 Fr system and then expand to 14-20 mm without overstretching the arterial lumen and causing stenosis, medial laceration or unwanted inflammatory responses. It needs to have enough force to at least growth with the vessel even after neointima formation. In this study, the stents in smaller vessels had higher mean nominal stent diameter to artery diameter ratios and higher degrees on medial injury. However, the long-term consequences of this medial injury remain unknown and it can be mitigated using lower radial force stents.

The appropriate design of such products requires this kind of data. Our analysis shows that no one risk management tool fits all growers. Some risk-related patterns may be observed broadly in certain segments of farms. However, those patterns change when smaller subcategories of crop producers are analyzed because risks and the way growers manage them depend on many complex factors. One implication is that insurance products that are designed and targeted for individual crops may miss the whole farm interactions. In reality, an insurance product for a specific crop would work differently for different growers depending on their characteristics outside the specific crop. It is also vital to better understand the risk management tools that growers currently use when designing public policy to help farmers manage risk. In many cases, public policy for risk management can be effectively designed to accommodate and complement rather than substitute for or conflict with the risk tools that growers already value and use. Overall, the results of this survey suggest that one must proceed with caution when attempting to develop government-sponsored risk management programs. Programs may fail to meet objectives and may have serious unintended consequences unless the full set of opportunities and constraints facing farmers is well understood and the differences across farms are incorporated in the program design. This study shows the complexity of risk related costs and revenues associated with the fruit, nut, vegetable, blueberry grow bag and ornamental horticulture industries in California. The data summarized in this report also can be useful for further research.

These data, together with information on grower costs and returns, can help analysts better understand variations among horticultural crop industries in California and elsewhere. Researchers are also pursuing more detailed analyses of the data. For example, these data are ideal for measuring patterns of diversification and, in some cases, vertical integrations and for examining the multivariate patterns of these with alternative measures of farm size. Assessing other, more detailed relationships among the variables is also on the research agenda. This report does not attempt to disentangle the various causal relationships among the data. Such research is on the horizon. Finally, this survey provides a one-time cross-section on many important variables. Periodic re-surveys would allow researchers to track the path of adjustment and allow assessment of industry dynamics with rich, repeated cross-sectional information.Bunch grapes , notably European , are considered among the major fruit crops worldwide, producing roughly 70–80 million tons each year . Cultivars of V. vinifera L. are used for wine, juice, and table grape production. Grape berries are classified as non-climacteric fruits, exhibiting a double-sigmoid developmental pattern with two rapid growth phases: the berry formation and the ripening phase , separated by an intermediate lag phase called the green plateau . The exponential increase in berry size characterizes both growth stages , but not the lag one . During phases and , also known as immature stages, organic acids, mainly tartrate and malate, accumulate leading to induction of acidity levels . At the end of the lag phase, a step-change point takes place known as veraison, where acidity starts to decline while sugars, mostly glucose and fructose, as well as anthocyanins in colored varieties, increase.

Of particular interest are phenolic compounds, which are major and ubiquitous plant secondary metabolites derived from the shikimate/phenylpropanoid and polyketide pathways, with three utmost categories: proanthocyanidins , also known as condensed tannins, the gallo- and ellagitannins , and the phlorotannins . Such diversity of polyphenols, with more than 8000 structural variants, bestows them a wide range of biological functions ranging from growth, development, and protection inside the plant to, to some extent, human-related issues . In grapevines, the accumulation pattern of phenolic compounds, along with the aforementioned berry attributes, distinguishes each of the berry phases throughout berry development . Indeed, berry quality and sensory characteristics are notably defined by its polyphenol content . Remarkably, astringency is among the hardest sensory traits to depict and interpret as many intricate processes underpinning its perception . For instance, a sensory characterisation of the astringency of 11 varietals of Italian red wine revealed that neither total phenols nor PAs can predict how all astringency subtleties will be perceived . It is worth noting that the amounts, compositions, and proportions of polyphenols in a given species may vary widely depending on several factors, such as genotypic variations, developmental stages, and environmental circumstances . Scarlet Royal is a mid-season ripening table grape variety, producing seedless, red-skinned, oval-shaped, firm, and moderate to large berries with a sweet to neutral flavor . In the San Joaquin Valley, California, it typically ripens in mid to late August, filling the harvest window between Flame Seedless and Crimson Seedless, and has thus become a very popular red table grape variety in California. However, an undesirable astringent taste has been observed occasionally in some cases.

In fact, the economic value of grapevines depends substantially on the environmental conditions, including climate, soil, cultural practices, cultivar, and root stock. Hence, the term “terroir” is used in viticulture to describe the effect of such an interactive ecosystem on grapevine and wine quality . The current study aimed to understand the underlying mechanism of astringency development in Scarlet Royal berries at two contrasting vineyards . The first location produces well-colored, non-astringent berries; however, the second site yields astringent taste, poorly colored berries . The data showed a large variation in berry astringency within the same vineyard and from year to year. The data illustrated that the divergence in berry astringency stemmed from alterations in its polyphenol composition , most notably tannins. Additionally, the ripening stage was the most distinguishing platform for such variation between both vineyards. We were able to determine the tannins’ threshold level that causes the Scarlet Royal astringency taste to be ~ 400 mg/L. Given the changes in the levels of polyphenols during berry ripening, the question was raised: what is the mechanism governing the distinctive tannins accumulation pattern between V7-berries and V9-berries, and hence astringency diversity? To answer this question, RNA-seq data generated at one ripening time point was associated to the changes in polyphenolic levels using a systems biology approach, WGCNA . The module-trait association analysis positively correlated the key flavonoid/PAs biosynthetic genes with the accumulation of tannins, catechin, and quercetin glycosides exclusively in V9-berries. The modulation of the berry’s transcriptomic profile is concomitant with its polyphenols’ composition, which finally disturbs berry quality, including astringency levels.Five-year-old V. vinifera cv. Scarlet Royal grafted on Freedom rootstock was chosen for its berry astringency diversity at two commercial vineyards located in Delano, San Joaquin Valley, California, USA. Vineyards were located at a close distance of 10 km, and the local weather conditions during the two seasons were collected from the Delano CIMIS weather station . Both vineyards were planted at the spacing of 2.44 and 3.66 m in an open gable trellis supporting system with East-West row orientation. Vines were pruned in a Quadrilateral cordon training with 7–8 spurs left on each cordon during the winter pruning. In addition, general UC guidelines practices were applied in both vineyard. Random forty vines from different four rows from each vineyard were used in this study. Starting from veraison and until the end of the season, during two consecutive years . During the first year, sampling dates were July 8th , August 1st , August 10th , September 9th , September 15th , and October 19th ; and for the second year, sampling dates were: July 15th , August 10th , August 25th , September 10th , September 29th , and October 21st . Sampling dates varied from the first to the second year due to the vineyard’s accessibility. At each sampling point, two sets of fifty berries were collected periodically. The first set was used to measure the berry weight, and then these berries were macerated in an electric blender, filtered through a paper towel, blueberry grow bag size and an aliquot of juice was used to determine soluble solids , pH, and titratable acidity . The TA and pH were determined by titrating a 40 mL aliquot of juice with 0.1 N NaOH to a pH of 8.2 using an automatic titrator Excellence T5 . Another random 50 berries from each replicate were collected for color, tannins, and phenolic compounds and sent immediately in a cooler to EST laboratories.

At harvest, which was during the month of September, an extra set of samples was collected and promptly frozen in liquid nitrogen and stored at −80°C for subsequent analysis, including RNA extraction and gene expression studies. Harvest time was determined by the growers, and the marketable clusters were picked based on the color, and yield was determined from the three harvest dates.At bloom, fifty leaves from each replicate were collected, resulting in a total of 200 leaves from each vineyard, for nutrient analysis. The leaf positioned at the front of the cluster was specifically selected, and the petiole was immediately separated from the blade. The petioles were transported to the laboratory, where they were triple-washed with distilled water to remove any impurities before being sent to a private laboratory for nutrient analysis. In the winter, soil samples were collected at a depth of 30 cm and at a distance of 30 cm from the vine. These samples were transported immediately to the laboratory for analysis. The nutrient content was determined using the methods described in US Salinity Laboratory Staff .The taste panel evaluation of Scarlet Royal table grapes was conducted with the participation of twelve nonprofessional panelists. Astringent taste perception was assessed using a scale ranging from one, representing an extremely low level of astringency, to seven, indicating an extremely high level of astringency. The taste evaluation was performed on 24 clusters from each vineyard. Phenolic compounds analysis. Total phenolic analysis was performed on 250 grams of whole berries by ETS laboratory using a reversed-phase HPLC method adapted from Price et al. .Total RNA was isolated from whole berry samples following the protocol described by Boss et al. . To remove any residual DNA, RNase-free RQI treatment was performed according to the manufacturer’s instructions , and the samples were further purified using the RNeasy mini kit . For RNA-seq analysis, a total of 8 RNA-seq libraries were generated, comprising four biological replicates from each of the two vineyards . The libraries were constructed as previously described using the NEBNext Ultra II RNA Library Prep Kit for Illumina . Subsequently, these libraries were pooled in equal amounts and subjected to paired-end 150-base sequencing on two lanes of the NovaSeq 6000 platform at the Novogene Co., Ltd .Illumina sequencing of the multiplexed RNA-seq libraries resulted in 8 FASTQ files containing sequences, and the dataprocessing followed the methods described in our previous work . In summary, the quality of reads was assessed using FASTQ before and after trimming with Trimmomatic v0.39 . Subsequently, the trimmed reads were quantified using Salmon in non-alignment based mode to estimate transcript abundance . Co-expression network modules were constructed using the variance stabilizing transformation values and the R package WGCNA . Before analyzing the data, lowly expressed genes among all sample types were removed by DESeq2, and the remaining non-lowly expressed genes of the 8 samples were used in module construction. The co-expression modules were obtained using the default settings, except that the soft threshold power was set to 9, TOMType was set to signed, minModuleSize was set to 30, mergeCutHeight was set to 0.25, and scale-free topology fit index was set to 0.8 . A module eigengene value, which summarizes the expression profile of a given module as the first principal component, was calculated and used to evaluate the association of modules with berry biochemical characteristics of V7-berries and V9-berries at the fifth sampling time . The resultant final WGCNA matrix had 42 modules with 17,553 genes. The module membership and gene significance values were calculated, subsequently the intramodular hub genes were identified .Scarlet Royal table grape is one of the major red varieties in California. Despite the premium fruit quality of the variety, in some cases, an undesirable taste was observed under certain unknown circumstances. To gain comprehensive insights into the development of the occasional berry astringency of Scarlet Royal and understand the underlying mechanism of this phenomenon, berries were investigated at two contrasting vineyards , both following the same commercial cultural practices.

The economic sustainability of individual farming operations and the area’s berry industry in total will ultimately be impacted by and continue to evolve with the ever changing business environment, and by an array of risks and challenges.Angle-resolved photo emission spectroscopy is used to directly measure the band structure of solids and is an essential experimental tool for solid state physics research. In addition to the band structure, ARPES provides information on other aspects of the electronic structure. For example, ARPES with a spin detector can be used to obtain spin information of the initial states. Polarization dependent experiments can provide symmetry information on the initial states; initial states from, for example, px and py orbitals can show dramatically different ARPES intensities depending on the polarization of the incident light. In recent years, there has been much interest in using circular dichroism in ARPES as a way to measure some aspects of initial states, such as the orbital angular momentum or the Berry curvature. It is well understood that OAM plays an important role in spin-split phenomena in systems without inversion symmetry, such as surfaces of solids and monolayer transition metal dichalcogenides. CD-ARPES has been utilized to obtain the crucial information on the electronic structures of such systems. While the final state of the photoemission process certainly has an effect on the CD-ARPES intensities, plastic grow bag experimental results show that CD-ARPES is a rough measure of the OAM of the initial state if the photon energy is not too low.

Exploiting this feature in CD-ARPES measurements, information on the OAM and hidden Berry curvature of 2H-WSe2 was recently obtained using CD-ARPES. An important aspect of this research was that the Berry curvature contribution to the CD-ARPES intensity could be isolated by decomposing the CD-ARPES intensity map into symmetric and anti-symmetric components about the experimental mirror plane, which is perpendicular with respect to the crystal mirror plane of 2H-WSe2. The symmetric component was attributed to the OAM or Berry curvature contribution, since the electronic structure should be symmetric about the chosen experimental mirror plane set along K–Ŵ–K′ in momentum space.Experimental geometry, including single crystal orientation, is especially important in this experiment. The crystal structure of the top atomic layer or ML of 2H-WSe2 is a hexagonal lattice, as shown in Fig. 1a; there is a unique mirror plane in the crystal structure, as indicated in the figure. The experimental mirror plane is defined by the plane defined by the normal of the sample surface and the direction of incident light. Two experimental geometries are possible, according to the direction of incident light, as indicated by blue and red arrows in Fig. 1a. The experimental geometries using incident light described by blue and red arrows are regarded as geometry-A and geometry-B for convention, respectively. Notably, the signals from the top layer of bulk 2H-WSe2 dominate the CD-ARPES data due to the surface sensitivity of ARPES; the corresponding momentum space view is shown in Fig. 1b.

The mirror plane is oriented along the M–Ŵ–M direction, and the direction of incident light is indicated by blue and red arrows on the mirror plane in Fig. 1b. This experimental geometry differs from that used in previous work, in which the experimental mirror plane was rotated by 30° with respect to the crystal mirror plane, such that the experimental mirror plane is oriented along the K–Ŵ–K′ direction. We expanded on our previous CD-ARPES work on 2H-WSe2 by focusing on a different mirror plane. Here, we report our CD-ARPES studies on 2H-WSe2 with the experimental mirror plane parallel to the crystal mirror plane or along the M–Ŵ–M direction in momentum space . Within the experimental constraint, there are two possible experimental geometries based on the incident beam directions, as shown by the blue and red arrows in Fig. 1a,b. The CD-ARPES values for the two geometries are nearly opposite to each other near the Brillouin zone corner, whereas they are almost identical near the Ŵ point. These observations are well explained by accounting for the Berry curvature contribution to CD-ARPES. Our results thus indicate that the deviation from the median value between the two experimental geometries can be interpreted as the Berry curvature or OAM. Figure 1c,d present the constant energy ARPES maps taken by RCP and by LCP incident light in geometry-A, respectively. The binding energy of all maps shown in Fig. 1 is 0.5 eV lower than the valence band maximum energy . CD signals, in which the intensity corresponds to the difference in the intensity taken by RCP and that taken by LCP , are mapped in the momentum space .

The anti-symmetric function of the CD map for the experimental mirror plane is expected for this experimental geometry, given that the Berry curvature is also anti-symmetric with regard to the experimental geometry. Figure 1f–h present the ARPES maps taken with RCP and LCP incident light in geometry-B and the corresponding CD map, respectively; the upper left corner corresponds to the K′ point in Fig. 1f–h and the K point in Fig. 1c–e. Remarkably, the CD signals at each corner of the BZ in Fig. 1h are almost opposite to those in Fig. 1e, whereas the CD signals near the center of the BZ are nearly the same. This can be explained by taking the Berry curvatures into account, given that the Berry curvatures are opposite at the K point and K′ point, whereas the Berry curvatures are nearly zero around the Ŵ point. A detailed analysis of CD data was performed for ARPES cut data along the K–M–K′ and K′ –Ŵ–K directions in geometry-A and along the K′ –M–K and K–Ŵ–K′ directions in geometry-B . Figure 2a,b present ARPES spectra taken by RCP and LCP light, respectively, in geometry-A along K–M–K′ , as indicated by the dotted line in Fig. 1e. Figure 2d,e present ARPES spectra taken by RCP and LCP light, respectively, in geometry-B along the K′ –M–K direction, as indicated by the dotted line in Fig. 1h. Two parallel dispersive bands are evident in the spectra, of which the maxima are located at K and K′ . Te energy difference between the upper and lower bands originates from atomic spin–orbit coupling of the W atom. The spin directions of the two bands are opposite, but the Berry curvature and OAM are the same, as expected from the massive Dirac–Fermion model. ARPES intensity clearly depends on the polarization of the incident light. Figure 2c,f present CD-ARPES intensity distributions for geometry-A along K–M–K′ and for geometry-B along K′ –M–K, respectively. Te CD intensities of the two bands are similar at each momentum point, but the intensities are almost opposite between the CD for geometry-A and that for geometry-B; this is consistent with the constant energy maps shown in Fig. 1e,h.Normalized CD intensities as a function of momentum are shown in Fig. 3a for the upper band and in Fig. 3b for the lower band. INCD is obtained by /, where IR and IL correspond to the ARPES intensity taken with RCP and LCP, respectively. INCD for the upper band along K–M–K′ in geometry-A, as indicated by the filled squares in Fig. 3a, has a positive value toward the K point from the M point. INCD exhibits a slight sign change beyond K and K′ points, pe grow bag although it is difficulty to catch the fact in Fig. 2c due to very weak ARPES intensities. INCD for the upper band along K′ –M–K , indicated by the empty squares in Fig. 3a, exhibits a negative value toward the K′ point from the M point and a positive value toward the K point from the M point, except very close to the M point, as we can also notice in Fig. 2f; sign changes beyond K′ and K were also evident in the data. The INCDs in geometry-A and -B are roughly opposite, but not exactly. The INCD for the lower band in geometry-A and geometry-B are also similar to those of the upper band, but they are slightly weaker. INCD consists of symmetric and anti-symmetric functions about the experimental mirror plane . Figure 3c,d present the INCD S s for the upper and lower bands from two geometries, respectively. Figure 3e,f present the INCD A s for the upper and lower bands from two geometries, respectively. As shown in the figures, the INCD S s were close to zero, and INCD A s were dominant components, regardless of the geometry or band. An asymmetric CD-ARPES distribution about the experimental mirror plane is a usual feature from solids, as the inversion symmetry along the surface normal direction is lifted on the surface of solids, which is similar to an oriented CO molecule system.

The CD-ARPES contribution caused by the inversion symmetry breaking in the material surface can be called surface effects. However, it is surprising that the CD was nearly opposite between geometry-A and -B. Based on this finding, we believe that a substantial portion of INCD A originates from the Berry curvature , given that the CD signs follow the Berry curvature direction, as shown in Figs. 1e,h and 2c,f. It is important to isolate the Berry curvature contribution to INCD A from other contributions. The Berry curvature contribution to CD-ARPES should be exactly opposite between the normalized CD-intensities along K–M–K′ in geometry-A and along K′ –M–K in geometry-B, because the Berry curvatures themselves are exactly opposite for K and K′ points. We assume that other contributions, mainly the surface effects, are the same, regardless of the geometry. Ten, the median values of INCD A s from geometry-A and -B can be considered from the other contributions to INCD A s. Additionally, this assumption is experimentally justified by CD-ARPES data near the Ŵ point, as shown in Figs. 4 and 5. The difference in INCD A with respect to the median value is exactly opposite between the K–M–K′ cut in geometry-A and the K′ –M–K cut in geometry-B; this difference can be interpreted as the Berry curvature contribution to INCD A . Figure 3g presents the differences, along with the theoretical values of the Berry curvature and OAM. The differences are similar to the Berry curvature and OAM, except for the crossing at zero and the changing signs near 0.7 Å−1 . The sign change of the difference of INCD A from the median value is mainly due to the change in the final state character as the momentum of the photoelectron varies. We know that the wave function characters of the initial states near the K point change gradually and depend on the distance from the K point in the massive Dirac–Fermion model. The sign of CD-ARPES data can be reversed for the same initial states by only changing the final states, as indicated in the photon energy dependence of CD-ARPES. Figure 4 presents the ARPES cuts and CD-ARPES data along the K′ –Ŵ–K in geometry-A, and along K–Ŵ–K′ in geometry-B, as indicated in Fig. 1. These cuts are special, in terms of the Berry curvature and OAM of the electronic states near the Ŵ point being almost negligible, compared with those of states near the K point. Therefore, the Berry curvature contribution to CD-ARPES data is expected to be almost zero near the Ŵ point. The CD-ARPES signals in both geometries are quite strong near the Ŵ point and exhibit a clear node at Ŵ, indicating no symmetric component of the CD intensity. Te CD-ARPES intensities near the K point from both geometries are much weaker than those near the Ŵ point, and the CD-ARPES intensities near the K point from geometry-A are even weaker than those from geometry-B. Figure 5a–c present INCDs, INCD S s, and INCD A s, respectively. The symmetric components are negligible; the asymmetric components make up the majority of the INCDs . Remarkably, INCDs along K′ –Ŵ–K in geometry-A and along K–Ŵ–K′ in geometry-B are the same near the Ŵ point , and INCD A s are, in turn, the same near the Ŵ point . Figure 5d presents the deviations of INCD A s from the median value, along with the theoretical values of the Berry curvature and the OAM.

People’s Grocery had taken root. Ahmadi, an Iranian American from Los Angeles who studied Sociology at UC Santa Cruz, had been active in Oakland’s EJ movement for a couple years before starting People’s Grocery. Like the EJ movement, food justice shared an emphasis on environmental racism, economic and health disparities. Ahmadi felt that it was a logical progression from EJ to food justice, that food justice was in fact an “outgrowth of EJ” . The link between EJ and food justice made sense at multiple levels: “Nutrition, and land, and economic development. Those were really kind of the three things that started to triangulate for me” . Simultaneously reading up on the “social determinants of health” literature, and specifically interested in the relationship between malnutrition and resistance to toxins, Ahmadi turned to the work of Carl Anthony and Urban Habitat to guide his thinking about land use and structural racism. He continues, “[I was] craving something different, craving to be more entrepreneurial, craving to create alternative models. I connected the dots and saw this food security issue, and started learning about that.” Ahmadi found that food justice was a way to tackle multiple drivers of inequality in West Oakland, but only if it helped the community move away from a dependant “recipient” model towards a more economically self-sufficient one. Ahmadi’s story highlights the emphasis on growth and change, plastic square flower bucket on sustainability and community development that dominates the discourse employed by urban agriculture and food justice organizations.

For many activists, there is a sense of personal satisfaction or fulfillment that arises from developing creative strategies for changing the food system, from envisioning what a just sustainability might look like, and actively working to achieve this alternative vision. The material realization of this vision—a garden, a farm stand, a grub box—and the labor necessary to bring them to fruition, serve both the individual activist and the surrounding community. In East Oakland at the turn of the millennium, urban agriculture was mostly taking place in school gardens, community gardens, and people’s backyards, rather than through organizational garden projects. In terms of organized food justice-oriented urban agriculture activity, Grey Kolevzon’s work with Cycles of Change and EBAYC described in the previous section was concentrated primarily in San Antonio and Fruitvale. Few food justice organizations ventured into “Deep East Oakland”, the area east of Fruitvale, comprising a number of flatlands neighborhoods such as Elmhurst, Eastmont, and Melrose. Jason Harvey, founder of Oakland Food Connection, often tells the story of growing up in East Oakland where his mother supported him and his brother on food stamps. After a stint in the Air Force, Harvey returned to Oakland and got involved with the West Oakland Food Collaborative in 2003 . In early 2005 he began scouting out the work of the various organizations and noted that very little food justice work was happening in East Oakland where he had grown up.

Soon after he established Oakland Food Connection, formally establishing it as a 501 in 2007. Much of his work is concentrated in the area along MacArthur Boulevard in East Oakland, with a small farmer’s market, café, and bulk whole foods retail outlet in the Laurel neighborhood, a rooftop garden at E.C. Reems Academy, a charter school next to Castlemont High, his alma mater, as well as gardens at a handful of other schools . He focuses on both food production and culinary education, underscoring the linkages between “food, community, and culture” . Another East Oakland urban agriculture program grew out of Slide Ranch, an educational farm in Marin County where schoolchildren from San Francisco, Oakland, and Richmond learn about sustainable agriculture on one or two day field trips. Four of the garden-based educators working there were inspired by the way the children “blossomed” at Slide Ranch, but wanted to create a similar space within an urban area itself rather than busing them to a rural area. So they began searching for a space in Oakland and found an apartment with a large yard “perfect for a garden” advertised on Craigslist. They moved into the apartment on 23rd Avenue and International Blvd. in East Oakland’s San Antonio District . Shereen D’Souza, a South Asian American who grew up in New Jersey, had been working with hillside farmers and starting school farms in rural Honduras, before moving to SOL in 2004 on the invitation of one of the founders. She worked for Oakland Based Urban Gardens in West Oakland as a garden-based educator for several years before taking the helm of the California Food and Justice Coalition, a statewide food justice policy advocacy group. She describes SOL as “a living space, as well as a food justice project… We grow as much of our own food as possible, we have chickens and gardens, we buy bulk food from either Mandela Foods Coop or Rainbow and also if we need produce we go to the farmers markets” . SOL offers classes on sustainable agriculture and urban agriculture to neighborhood school groups, “and for older students, a critique of the industrial food system” . Mostly the youth come to SOL with other organizations that have included Bantaay Srei, an organization that helps Southeast Asian girls transition out of sex work; Street Level Health Project, an organization working with the children of jornaleros ; and Cycles of Change, a bicycle-oriented job training and education organization.

Their central program is a summer intern project for teens. She explains that SOL’s reach is limited due to meager funding. This was by choice, as their focus has primarily been on creating a sustainable living center rather than an NGO. Hayes’ Office of Sustainability focused primarily on reducing energy use and bringing hybrid and hydrogen vehicles into the public transit fleet. Under Hayes’ tenure, Oakland also joined the Chicago Climate Exchange, and teamed up with Greenpeace, Friends of the Earth, and the Cities of Boulder, Santa Monica, and Arcata in a lawsuit against several federal agencies for violating the National Environmental Policy Act by funding “certain overseas industries that exacerbate climate change” . In 2005 Mayor Jerry Brown, along with the mayors of 50 other cities around the world, signed the UN World Environment Day Urban Environmental Accords and pledged that Oakland would become a more ecologically sound, economically dynamic, and socially equitable city by 2012. As a result of steps taken toward this commitment, it ranked in the top ten sustainable cities in 2005, 2006, and 2008 . The high sustainability rankings were due in part to the city’s inclusion of the food system into its sustainability plan. In January 2006 on the recommendations of the Life Enrichment Committee, the Oakland City Council authorized the Mayor’s Office of Sustainability “to develop an Oakland food policy and plan for thirty percent local area production” . Building on a food assessment for Alameda County conducted in 1999, and inspired by similar assessments in Toronto, Vancouver, San Francisco, Portland, Chicago, and a number of other North American metropolises, two UC Berkeley graduate students in the Department of City and Regional Planning completed the Oakland Food Systems Assessment for the Mayor’s Office of Sustainability in May 2006 . The document has since served as a springboard for food systems change in Oakland. Upon the report’s recommendation, the City Council unanimously passed Resolution No. 80332, approving a seed grant for $50,000 to establish a municipal food policy council whose mission would be “to cultivate a sustainable food system by eliminating hunger, plastic plant pot increasing health, expanding a greener economy, and honoring diversity for all current and future generations of Oakland, especially the least served, by ensuring the availability and accessibility of a wide variety of local, safe, sustainably-grown, and nutritious food” . The Oakland Food Policy Council was seated in 2009 and has since developed an Action Plan that includes first steps towards “transforming Oakland’s food system,” including advocating for the protection and expansion of urban agriculture . 94 Arising from the same food systems vision, the Health for Oakland’s People and Environment Collaborative, an umbrella organization consisting of several community development organizations and spearheaded by the Alameda County Public Health Department, the Food Bank of Alameda County, and the Community Food Security & Nutrition Policy Program of Alameda County UC Cooperative Extension, competed for and won a two-year planning grant in 2007 for $495,200 from the W.K. Kellogg Foundation to develop a municipal program encompassing economic development, local food systems, green built environment, and public health education. HOPE was unique in the diversity of stakeholders it brought together: city officials, non-profit workers, food justice activists, students, homeless people, and homemakers. Teams of Collaborative members surveyed six “micro-zones”, # mile radius areas surrounding central intersections in the six poorest flatlands neighborhoods, interviewing community members and surveying food prices and availability in local stores.

They also conducted several community listening sessions and design charettes and funded an inventory of vacant land in Oakland with agricultural potential which has since been used by the OFPC and Oakland Climate Action Coalition to support their recommendations.95 HOPE continues to serve as the community engagement arm of the OFPC.While Oakland briefly seemed to be a national leader when it came to formally expanding urban agriculture thanks to the release of the Oakland Food System Assessment, the activity of the HOPE Collaborative, and the creation of the OFPC, municipal interest in urban agriculture briefly waned. The election of Ron Dellums as Oakland mayor saw the dissolution of the Mayor’s Office of Sustainability and the city’s entire sustainability program was shifted onto the shoulders of one man in the Public Works Department. Other cities soon took up the mantle, making strides in urban agriculture policy: Seattle, for example, declared 2010 as the “Year of Urban Agriculture” and passed a sweeping overhaul to allow the expansion of urban agriculture ; Cleveland legalized livestock ownership and committed $1.1 million to a pilot urban farm . In San Francisco, efforts to scale up urban agriculture through policy reform gained momentum, as well, ironically due to the visibility of urban agriculture across the Bay. Mayor Gavin Newsom actually announced his Healthy and Sustainable Food for San Francisco Directive in July 2009 standing in front of City Slicker Farms’ WOW Farm in West Oakland, “a junkyard-turned-farm in West Oakland that could serve as a model for how land could be converted in San Francisco” . The Directive signaled municipal commitment to improving the food system, and specifically addressed the importance of encouraging urban agriculture through “community, backyard, rooftop, and school gardens, edible landscaping, and agricultural incubator projects” and ordered all city departments “having jurisdiction over property [to] conduct an audit of land suitable for or actively used for food producing gardens or other agricultural purposes” , a response to public pressure to facilitate urban agriculture on the city’s more than 3,000 privately owned and 2,000 publicly owned vacant lots in the city . In the year and a half that followed, an umbrella organization of urban agriculture activists called the SF Urban Agriculture Alliance , working in conjunction with the SF Food Policy Council , pushed through one of the nation’s most comprehensive pieces of urban agriculture legislation: Ordinance 66-11. Passed by the City’s Board of Supervisors in April 2011, it greatly expanded the area where urban agriculture is permitted in San Francisco and allowed sales of produce by home gardeners . Back in Oakland, despite the dragging of feet by the Dellums administration, interest in urban agriculture is slowly managing to take root within City Hall. These changes were due to the activity of the OFPC whose recommendations received airtime during the 2010 mayor race. At-Large Council Member Rebecca Kaplan, during her bid for election in the 2009 mayoral race, included food issues in her platform and has consistently advocated for adopting the OFPC’s recommendations. While she did not win the election, she continues to advocate for progressive food system overhauls from her seat on the Council, including the expansion of urban agriculture in the city. At the January 2011 presentation of the OFPC’s Transforming the Oakland Food System report to a Council sub-committee, Kaplan lobbied the committee to support the OFPC’s recommendations for urban agriculture zoning changes.

Such coping mechanisms generally shift an additional burden onto the shoulders of urban women, in particular . In addition to expending her energy on food production and jobs in the informal economy, a female farmer may also divert income earned from sale of surplus produce towards the purchase of additional ingredients for a meal; as a Senegalese extensionist explains, “Whatever a woman earns [from her gardens] goes directly into the cooking pot” . A straightforward Marxian analysis of the combined impact of low wages and dispossession from the land can largely explain the rise of urban agriculture and its continued presence in the Global South. Indeed, primitive accumulation is ongoing as Southern countries integrate more fully into the global economy and communally managed property “enclosed” by titling arrangements and emerging land markets. In the North, however, such processes happened longer ago; it is therefore helpful to draw also on the work of Karl Polanyi in order to understand how social rift has produced urban agriculture in the North. Polanyi describes in detail how land, labor, and money are bought and sold as “fictitious commodities”, fictitious because they were not produced to be sold as a commodity. Under the expansion of laissez faire economic liberalism, they are increasingly subject to the whims of the free market . In times of economic crisis, when the market value of the fictitious commodities fluctuates dramatically, an “avalanche of social dislocation” tends to follow . Wages left to laissez faire or free market logic decline as surplus labor enters the market , round flower buckets depressing wages which lowers work and living standards .

Land—and by extension natural resources—valued only as a production input or commodity for exchange can be over-exploited for short-term gain with little consideration of its long-term productivity. In sum, “leaving the fate of soil and people to the market would be tantamount to annihilating them” . To protect people from extreme social dislocation, a “protective counter-movement” inevitably arises which ranges in form from communal networks of support to government intervention and regulation. With the rise of rapid urbanization during the industrial era, urban agriculture repeatedly arose as part of a counter-movement to protect the population from the social dislocation resulting from “leaving the fate of soil and people to the market.” Subsistence food production was part of the American and European urban landscapes well into the 20th century. As urban areas developed during industrialization, urban agriculture often served as a coping strategy, significantly subsidizing the social reproduction of workers as in the South today. In Britain, the Commons Act of 1876 and various Allotment Acts obliged local governments to provide citizens with space for food production . In the US subsistence production was actively practiced and encouraged well into 20th century in urban centers such as Los Angeles, where chickens, pigs, beans, and tomatoes were common sights in the small yards of worker housing . Community gardens in the US and allotment gardens in the UK grew in number during times of economic hardship and austerity, but not due to household coping alone. Governments often orchestrated the growth of urban agriculture during these crisis periods as a part of a coordinated protective measure. Urban food production served not only to buffer food security, but also to quell potential unrest .

As America industrialized in the late 19th century, a growing pool of unemployed gathered in urban areas. Municipal governments provided garden plots and seeds to stave off hunger and unrest. During the Depression of 1893, the mayor of Detroit launched a so-called Potato Patch plan—later adopted across the US—to provide the unemployed with vacant lots between # and 1 acre each. More than 1,500 families farmed small vacant lots between an eighth- to a half-hectare each on 455 acres . Gardens were intended not only to provide food and employment, but also to create self-respect and to help assimilate recent immigrants. During the Great Depression urban agriculture again provided food and jobs for the masses of unemployed. The New Deal Federal Emergency Relief Administration spent $3 billion on relief gardens between 1933 and 1935 alone. One gardening program in New York City transformed 5,000 vacant lots into highly profitable gardens by 1934 . Garden programs also exploded during wartime. Liberty gardens proliferated in the US during the First World War as a government response to the food riots gripping the nation. Under the guidance of the National War Garden Commission, more than 5 million gardeners cultivated “idle” land. During World War II, under the National Victory Garden Program 20 million gardens produced 40 percent of America’s food by 1944. During the economic recession of the 1970s, “inflation” gardens flourished in America’s inner-cities with a boost from the back-to-the land ideals of the environmental movement and the USDA’s $1.5 million Urban Gardening Program.

During this period community gardeners and activists took over thousands of vacant lots left fallow as industrial and residential capital abandoned US cities . The discourse of crisis driving these programs was used not only to justify urban agriculture, but also to denigrate it as an act of welfare for the poor once crises had passed. As such, crisis discourse helped to obscure the subsistence role that urban agriculture has always played in urban landscapes, as well as to devalue urban agriculture in times of prosperity . Indeed, when the economy improves and adjacent land values rise, urban agriculture is no longer seen as a public good but an obstacle to development. In New York’s Lower East Side during the 1970s, for example, municipal government promoted community gardens as “a productive use of land considered to be relatively useless.” The gentrification of nearby SoHo in the 1980s, however, led to rising land values and a growing interest in development, and eventually to a moratorium of leasing vacant land for gardens and the bulldozing of several squatter gardens. Tensions also arose within the community over whether to use vacant lots as space for gardens or for low-income housing . These tensions between development and urban agriculture are often racialized, as in the case of the South Central Farms. The 14-acre community garden was originally established in 1993 by the Los Angeles Regional Food Bank in an effort to bring healthy food to the impoverished neighborhood. In the now famous case, the gardens were bulldozedin 2006 following a long and nasty legal and political battle between Latino/a activists, a black city councilor, and a white Jewish land owner . 31 Urban agriculture’s relation to social rift does not lie with land alone. Food, even while produced as a commodity in the capitalist agri-food system, functions in a similar manner to Polanyi’s other fictitious commodities. Understanding food as a fictitious commodity like land further clarifies urban agriculture’s ability to mend social rift. Its treatment as a simple commodity to be bought and sold according to market logic effaces the complex weave of relations running through its production, distribution, preparation, and consumption. The rapid transformation of the agri-food system during the 20th century was due in large part to the expanded commodification of food, from patented seeds to artificial ingredients and fast food restaurants. As food has become increasingly processed and packaged, the culture and traditions surrounding food production and consumption have gradually been obscured by the market based ideology of cheap food . The socio-cultural significance of food and agriculture rarely factors into calculations of profit margins; certain social relations woven into the agri-food system—agricultural and culinary knowledge and its cultural significance, for example—are impossible to quantify and either resist commodification or are erased by a commodified agri-food system. Since the middle of the last century, plastic flower buckets wholesale the commodification of food has systematically unraveled many of these existing social relations and created new commodity-driven relations of production and consumption that “undermine the source of all wealth—the soil and the worker” at multiple scales . Farming has evolved into a highly-specialized industry based on inputs and outputs and which engages less than 2 percent of the U.S. population; over-application of agri-chemicals have poisoned farmworkers and created a massive “dead zone” in the Gulf of Mexico; agricultural and culinary knowledge have been lost; diabetes, heart disease, and obesity have followed on the heels of junk food consumption worldwide. As a protective counter-movement, urban agriculture attempts to mitigate social rift by de-commodifying land, labor, and food. Various case studies in North America have illustrated how gardens are a site of interaction between various ages and ethnic groups, where knowledge about food production and preparation is shared and community ties strengthened .

Urban agriculture produces new commons, by returning—at least partially—the means of production to urban populations. The verdure emerging from cities’ marginal spaces—road medians, infrastructure rights of way, vacant lots, wasteland—signals both a reclamation of what remains of the commons and the creation of new commons from the interstitial spaces skipped over by capital or left fallow in its retreat. While the forces giving rise to it differ between the Global North and South, urban agriculture joins together these tiny tesserae into a fertile mosaic in both places, where gardens grown along the abandoned railroad right of way in Detroit are not unlike those growing alongside rusted rails in Bamako. Goats and cattle graze weeds growing up amid the cement blocks and rebar of all-but-abandoned buildings. A bean patch is tucked in the 3-meter wide strip of road shoulder between the asphalt and the wall of a government building. An abandoned racetrack is a patchwork of vegetable gardens irrigated from a nearby drainage ditch. Industrial brown fields in the US and Europe are transformed into urban green space dotted with community gardens .Social and ecological dimension alone cannot fully explain the rise of urban agriculture in the North. For many, a certain lifestyle politics drives the attraction to the urban farming; “getting in touch with nature” or “learning where our food comes from” are common tropes. As a broader social rift is cleaved by the commodification of land and labor, people experience an internalized dimension of metabolic rift, which I refer to as “individual rift”. Essentially what Marx called alienation from labor and from nature, it manifests as the perception of self as external to the environment. While this dimension of metabolic rift is perhaps the most difficult to overcome due how deeply rooted it is in the social processes outlined above, individual rift can be addressed—and potentially overcome—through urban agriculture more easily than can other forms of rift precisely because it arises at the level of the individual consciousness. Two interrelated forms of alienation are central to individual rift: alienation from labor and alienation from nature. First, individual rift arises from our alienation from the fruits of our labor. As discussed above, the social rift in metabolism arises from the commodification of labor and the separation of the worker from the means of production . What this means is that under capitalist production a wage laborer no longer owns the finished product he or she creates. Rather than producing something for his or her own use, the worker produces it for the capitalist to sell as a commodity to earn profits used to fuel further accumulation. As Sohn-Rethel argues, the root of this alienation lies in the division of intellectual and manual labor, a long historical process cemented at the dawn of capitalism via the rationalization of labor and which intensified individual rift.33 The later “Balkanization of knowledge” into social and natural sciences encouraged the division of labor, further alienating humans from nature as a result of the “inadequate understanding of how these knowledges connect with one another in the process of producing the concrete outcomes in which we are interested” . Due to this division of manual and intellectual labor, the rationalization of production through technological advances and the de-skilling of labor has further alienated the worker from the product and the whole process of production. In short, the more that science enters into production, the less the worker understands about the process of production and the more his or her creative capacity is undermined . Second, the separation from land as discussed in the previous section is central to individual rift. From both ecological and Marxian perspectives, humans simultaneously shape and are shaped by the ecosystems to which we belong. More specifically, we are the nature around us. Nature is, Marx theorized, integral to human life and development .

Additionally, our study provides valuable insight into areas of greatest risk for dieback and mortality, which are predominantly in lower elevations. These are important factors to consider when predicting vulnerabilities and potential impacts of future extreme drought events . Mediterranean shrublands like those in southern California already considered high risk for global-change type drought, , and research suggests a general trend of upwards-shifting ranges in southern California chaparral species driven by changes in climate . Therefore, populations of A. glauca occurring at the lower edge of their natural range are at high risk for dieback and mortality, and should be the focus of management efforts. Lastly, while studies on the various physiological mechanisms for plant survival during drought are critical for predicting differential responses to stress, there is an increased emphasis on the importance of understanding the diverse role of pathogens in order to accurately model species vulnerabilities to climate change . Studies that incorporate the impact of pathogens help inform new integrative approaches to protecting plants against drought and biotic infection, rather than treating these influences separately. Examples include Jactel et al., , whose meta-analysis showed the significant effects of water stress on symptom severity in plants infected with latent pathogens like Bots, and experiments like Drake-Schultheis et al. , procona system who found interactive effects between drought stress and infection from N. australe in driving symptoms of stress and increasing mortality rates in A. glauca.

The results of our study align with these frameworks, and provide additional evidence that as climate change models are predicting more intense and frequent drought events, our need to understand the role of latent pathogens in at-risk natural systems is becoming more critical.Reports of large-scale, drought-associated mortality events in forest and woodland systems have been on the rise in recent decades . These reports have spanned across biomes, including in classically drought-tolerant species across Europe , Australia , Africa , and the United States . As a result, interest has been growing in understanding how species that are typically capable of withstanding periodic drought stress may become susceptible to drought and experience significant dieback and even large-scale mortality when exposed to acute or prolonged chronic drought . These droughts of unusual extremes are referred to as “globalchange-type drought” and are becoming more common as the climate warms . While the exact physiological mechanisms leading to dieback and mortality during such events are variable across species and conditions, drought is generally hypothesized to promote physiological decline either via loss of hydraulic functioning or carbon starvation or a combination of both . In the case of hydraulic failure, plants with insufficient soil water experience xylem cavitation , which can ultimately lead to cellular death. Alternatively, plants that avoid drought by closing their stomata to reduce water loss subsequently suffer insufficient carbon supply to meet other metabolic demands. In either scenario, the stress that drought places on a plant is likely to cause measurable decreases in physiological functions that may be irreversible .

An additional factor that can play a significant role in drought-related dieback and mortality is the presence or introduction of biotic agents. Indeed, introduced plant pathogens have been well documented to cause canopy dieback and dramatically alter community structure in a variety of forested systems . Some well-known examples in the United States include Dutch elm disease , chestnut blight , white pine blister rust , and sudden oak death . Significant pathogen events have also impacted the landscape in wild land shrub communities including sclerophyll shrub woodlands in Australia and salt desert scrub in the western United States . However, large-scale dieback of shrubs has been less documented than their arboreal counterparts, despite evidence of disease from fungal species being abundant in many scrubland systems including southern California chaparral , northern California foothill shrublands , and South African fynbos . Such studies, along with expectations of increasing threats from pathogens due to climate change and accelerating trade/movement of biological materials globally , have led scientists and land managers alike to anticipate introduced pathogens as important contributors to future changes in wild land communities.While both global-change-type drought and pathogens are likely important contributors to plant dieback and mortality, current research suggests that these two factors are not mutually exclusive . Rather, canopy dieback and mortality may result from the combined influences of environmental stress and biotic agents, and theoretical frameworks describing these influences have been put forth .

These frameworks incorporate biotic agents into the drought-hydraulics complex described above, whereby pathogens and insects may amplify or be amplified by drought-associated hydraulic failure or carbon starvation . Amplification can occur when biotic agents damage host tissue—by defoliation or blocking transportive vessels, for example—to the extent that the effects of drought are greatly exacerbated . Alternatively, physiological responses to extreme environmental stress can have negative effects on plant defense systems, rendering them susceptible to mortality through biotic infection . In both scenarios, the effects of biotic agents and drought stress are strongly linked, and these interactions have been well documented in drought-tolerant systems such as South African fynbos , red pine forests , eucalyptus forests , and California chaparral . Latent or secondary pathogens are particularly likely to be involved with dieback and mortality events in these systems, as they are known to increase damage in hosts experiencing drought stress . Therefore, while drought events alone are expected to play an important role in reshaping ecosystems as the climate changes, in some cases, synergies between environmental stress and biotic influences might lead to shifts in plant community structure and composition, and thus ecosystems as a whole. In the Santa Ynez Mountains in Santa Barbara County, California, United States, big berry manzanita began exhibiting dramatic canopy dieback during the 2011–2018 drought . Shrubs in the genus Arctostaphylos are common in Mediterranean shrub communities extending from southwest Oregon to northern Baja California . They may occur in monospecific stands or in alliances with other important community members like chamise and Ceanothus spp. . Within these alliances, Arctostaphylos spp. frequently occupy >50% average cover , which along with their nutritious and prolific fruits, and fire-induced regeneration strategies, make them one of the most important members of the chaparral community . In the southern California chaparral ecosystem where hot, dry summers with high vapor pressure deficit are the norm , seasonal drought tolerance has long been considered a common strategy among dominant plant species, including A. glauca. However, the severity of recent canopy dieback observed suggests that this species is reaching a threshold in its drought-resistance capability. Concurrent with observations of canopy dieback, visible symptoms of fungal infection were observed including wood cankers and leaf discoloration , both ofwhich progress during prolonged drought stress, suggesting that multiple driving forces contribute to manzanita dieback. Molecular sequencing identified the dominant fungal pathogen found on symptomatic A. glauca in this area to be Neofusicoccum australe, a member of the well-known pathogenic Botryosphaeriaceae family . Members of this family are most commonly associated with disease in plant species experiencing severe environmental stress , including Arctostaphylos spp. . They are also known to play a variety of functionally diverse roles, from asymptomatic endophytes to obligate pathogens . Yet, while N. australe has been described around the world , relatively few studies have been conducted on its specific interactions with host species, procona valencia buckets as it was only fairly recently described . Historically, Bot. pathogens have most frequently been studied in agricultural host species , and little is known regarding their ecological role in wildland ecosystems , especially with regards to chaparral shrubland systems . The present study was aimed at identifying the possible role of N. australe in A. glauca dieback in Santa Barbara County, particularly in combination with extreme drought. Because this pathogen has only recently been reported on wild shrub species in California and is thought to be an introduced species native to Western Australia , this outbreak represents a new and undescribed threat to these wild land plant assemblages. This study addresses the following questions: How does A. glauca respond physiologically to drought and fungal infection, separately and together? 

Are these responses correlated with visual signs of stress, specifically leaf health? Can drought and fungal presence interact to increase or accelerate plant mortality compared to drought or fungi alone in A. glauca? To address these questions, a greenhouse experiment was conducted in November 2016 through February 2017 manipulating both drought and fungal infection and observing trends in plant stress symptoms, physiological function, and mortality. We predicted that both drought stress and fungal infection would lead to declines in physiological function compared to the control and that these declines would be strongly correlated with increases in stress severity. Furthermore, we expected that those individuals experiencing both drought stress and fungal infection would die sooner than those in all other treatment groups. This experimental study elucidated the potential of the interaction between drought stress and introduced pathogens to significantly impact chaparral shrub health and important implications for the future of these shrubs faced with increasingly frequent globalchange-type droughts. A completely randomized full-factorial design was used to organize the individuals into four treatment groups: droughted and inoculated with N. australe , droughted and not inoculated , watered and inoculated with N. australe and a control; watered and not inoculated . Data were collected for ~90 days to track declines in health and mortality rates among the different treatments. Drought-treated plants received 1 L of water on the day of inoculation and another 0.5 L on day 38. Those with no drought treatment received 0.5 to 1.0 L of water by hand once per week depending on soil moisture, which was monitored regularly using a TDR machine from Soil Moisture Co. . Soil moisture for non-drought plants was maintained between 15–25% moisture for the entire experiment. Cultures for inoculations were made from re-isolations of field samples that were collected in January 2016 and positively identified to be N. australe . Inoculations took place on 3 November 2016 , using methods adapted from Michailides and Swiecki and Bernhardt . Mycelial plugs were made from 8-d-old cultures growing on half strength potato dextrose agar amended with streptomycin to prevent bacterial contamination. Plants were first sprayed with 70% isopropyl alcohol to sterilize the surfaces and surrounding areas. Mycelial plugs were taken from the advancing margin of N. australe cultures and placed on strips of Parafilm using sterile petroleum jelly for adhesion. Plugs were then placed to superficial wounds made on the main stem . The Parafilm strips were then gently wrapped 2–3 times around the stem to keep the plugs in place and prevent contamination. Those plants not receiving fungal inoculation received a control inoculation with uncultured potato dextrose agar using the same techniques. To confirm Koch’s postulates, the standard criteria to determine the agent causing a disease , we reisolated fungi from stem tissue at least 2-cm above the point of inoculation in harvested plants, amplified using primer pairs ITS1F/ITS4 for the ITS and EF1-728F/986R for alpha-elongation factor-1 . They were sequenced using the protocol described by Schultheis et al. . Greenhouse conditions were set to reflect summer conditions in Santa Barbara. Daily temperatures were maintained between 18–30°C during the day and 10–15°C at night. Humidity maintained at 50%. Photosynthetically active radiation lights were set to provide 14 h of daylight per day and a maximum of 2000 µmol. Plant positions were randomized weekly using a random number sequence generator to eliminate any microclimate effects in the greenhouse. Physiological stress due to drought and pathogen infection was inferred from weekly measurements of net photosynthesis and dark-adapted chlorophyll fluorescence using a LI-COR 6400XT and Hansatech FMS2 system fluorometer , respectively. Leaves were dark-adapted using leaf clips for 20–30 min before measuring fluorescence. One healthy , fully expanded leaf per plant, or on one healthy and one stressed/diseased leaf per plant if symptom onset had begun . All data were collected between 10:00 hours and 16:00 hours to capture peak values for the day, with the majority of measurements taken between 10:00 hours and 12:00 hours. Due to mechanical issues, chlorophyll fluorescence was not measured on 4 and 11 November and on 20 December 2016. Net photosynthesis and dark-adapted fluorescence were chosen as proxies for plant health, as lower values correlate strongly with higher levels of drought stress .