Due to concerns of flavanol monomer epimerization during cocoa production which might yield substantially less bioactive -catechin from naturally occurring -epicatechin the specific concentrations of catechin and epicatechin enantiomers of thinned clusters and cocoa powders are also provided in Table 2 using chiral chromatography to facilitate future epidemiological study designs.The same trend was observed for Chardonnay fractions as the less mature seed had the highest flavanols and procyanidins compared to its more mature dark seed fraction . However, for the Chardonnay seedless fractions, the dark fraction had a significantly higher amount than the light fraction . Ivanova et al. have found that the total content of catechin, epicatechin, and procyanidin dimers B1- B4 in Chardonnay and Merlot grown in R. Macedonia were significantly higher in seeds rather than in skins and pulp at veraison. Our data on flavanols and procyanidins DP 1–2 are in accordance with their findings as the highest content was found in Chardonnay seeds , followed by Pinot noir seeds , Chardonnay seedless , and Pinot noir seedless . Overall, 2.2-fold and 1.2-fold variations of DP 1–2 were found in Chardonnay and Pinot noir thinned cluster fractions, respectively. Previous studies also showed that flavanol monomers in white and red grapes slow down or stop accumulating from veraison to ripening while procyanidin dimers B1-B4 increase slightly until the intermediate phase . These all indicated that grape thinned clusters at veraison could be richer sources of monomeric and oligomeric flavanols and procyanidins compared to grapes during berry formation and berry ripening.
With the increasing interest in utilizing specific bioactive catechin and epicatechin enantiomers,hydroponic bucket mainly -epicatechin and -catechin, in epidemiological studies , we separated catechin and epicatechin enantiomers using chiral chromatography and presented the data in Table 2. Like grapes, the predominant forms of flavanol monomers in natural cacao beans are -epicatechin and -catechin. However, Payne et al. have found that various processing techniques used in cocoa production, such as fermentation and roasting at over 70°C, significantly decrease the total catechins amount and generate significant amounts of -catechin from -epicatechin epimerization, respectively. The Dutch processing is widely used in cocoa production where the cocoa is treated with an alkali solution to reduce the acidity and to intensify the chocolaty flavor in the final powder . Compared to natural cocoa powders, Dutch processing also caused a greater loss in both epicatechin and catechin according to Payne et al.As -catechin has been shown to have pharmacological effects including antimicrobial , antioxidative , and had about five times higher bioavailability than -catechin , thinned clusters could complement cocoa ingredients—a small portion of grape thinned cluster as an ingredient would likely make a positive impact on the -catechin and total catechins content of cocoabased products.Drosophila suzukii , also known as the spotted wing drosophila , is a vinegar fly originating from Southeast Asia. SWD was first detected in North America in August 2008 in Santa Cruz County, California, where it was observed infesting strawberries and caneberries.In 2009, SWD was detected in Washington, Oregon, and Florida. By 2010, SWD was detected in Utah, Mississippi, North Carolina, South Carolina, Wisconsin, and Michigan in the United States, and Alberta, Manitoba, Ontario, and Quebec in Canada.
Recent trapping indicates that SWD can be found in virtually any region of North America where host fruit are available. A coincidental invasion of SWD with a genetically distinct population has also been observed in Europe, with initial detections in both Spain and Italy in 2008, followed by its spread throughout the continent. In North America, SWD is primarily a pest of berries and cherries. In Europe, it is reported to also damage a number of stone fruits and grapes. Unlike native vinegar flies in North America and Europe, female SWD possess a serrated ovipositor that can pierce the skin of healthy, soft-skinned fruits to lay eggs. These eggs quickly develop into larvae, which consume the fruit and render it unmarketable. The only other Drosophila species known to oviposit in sound, marketable fruit is Drosophila pulchrella Tan. This species is native to Japan.1 Growers have attempted to mitigate crop damage risk by applying additional insecticide, harvesting more frequently, performing field sanitation, and implementing trapping programs to detect SWD populations. These management practices are costly and many growers still face significant yield losses from SWD infestations. Raspberry producers are perhaps the most affected by SWD’s invasion among California commodities, although producers of blueberries and cherries have experienced substantial losses too. Strawberry producers have experienced lower damage rates and primarily on the lower-value fruit produced for processing. SWD-related losses in these industries vary by year and crop depending on management practices, weather conditions, time of the year, and geographic location. A primary motivation for focusing on the California raspberry industry is that California accounts for the majority of raspberry production in the U.S. and the raspberry industry accounts for the majority of economic losses due to SWD among berry crops.A second motivation is the magnitude of change in pest management practices; few of the SWD control practices used by raspberry producers were needed to prevent injury from other pests prior to its establishment.
Economic losses in the California raspberry industry include the cost of managing SWD and the value of the fruit lost due to SWD infestations despite management efforts. First, we compute the cost of the chemical management programs and the labor-intensive sanitation practices implemented to mitigate SWD-related yield losses. Second, we calculate the industry level yield losses due to infestation. These components form an estimate of the full economic cost of SWD’s invasion into California raspberry production.In 2013, raspberries were estimated to be the twenty-seventh largest crop in California by value of production. The United States is the third largest producer of raspberries in the world, producing 91,300 tonnes, after the Russian Federation and Poland, which produce 143,000 and 121,040 tonnes, respectively. Across all counties, California’s raspberry production was worth an estimated $239 million according to the United States Department of Agriculture’s National Agricultural Statistics Service , and $437 million according to California County Agricultural Commissioners’ Reports.The difference in these estimates reflects that the NASS data report cash receipts to producers while the Agricultural Commissioners’ Reports estimate the total value of production. Figures 1, 2, 3, and 4 plot California raspberry hectares, production, yield per hectare, price per kilogram, and the total cash receipts between 2004 and 2013.Note that raspberry hectares multiplied by yield per hectare is equivalent to production, and production multiplied by price per kilogram is equivalent to total cash receipts. Four counties account for virtually all commercial raspberry production in California: Ventura, Santa Cruz, Santa Barbara, and Monterey.In 2014, Ventura County produced approximately 52% of California’s raspberry crop by value, $241 million, on 1,873 hectares. Raspberries are the third most valuable crop in Ventura County.9 Santa Cruz County produced approximately 28% of California’s raspberry crop by value, $131 million, on 979 hectares. Raspberries are the second most valuable crop in Santa Cruz County.10 Santa Barbara County produced approximately 10% of California’s raspberry crop by value, $45.2 million, on 591 hectares. Raspberries are the ninth most valuable crop in Santa Barbara County.Monterey County produced approximately 10% of California’s raspberry crop by value, $45 million, on 316 hectares. Raspberries are the sixteenth most valuable crop in Monterey County.Table 1 summarizes California raspberry production by county.Counties are listed from north to south along the Pacific Coast. Figure 5 identifies these berry-producing regions with a stylized map of California.Most commercial raspberry plantings in California have had an 18-month lifespan. The crop is planted in the winter and then harvested twice, first in the fall following planting and then in the subsequent summer. Both harvest seasons last approximately three months, with crews harvesting fruit every three days on average. Variations in harvest frequency depend on yields and pest management activities. Yields are low at the beginning and end of a harvest season,stackable planters and peak near the middle of a season. Pesticide applications may require an interval of time, depending on the particular pesticide, before normal harvesting activities can resume. This period is known as the pre-harvest interval , and it is determined by the U.S. Environmental Protection Agency. Occasionally, low yields are realized during the harvest season due to crop damage resulting from weather, pest activity, or other external factors. The summer harvest is typically larger than the fall harvest.Organically produced raspberries represent a significant share of total California raspberry production.
In 2008 and 2011, California’s organic raspberry production was valued at $11.4 million and $8.98 million, respectively, according to the USDA-NASS. In 2012, 408 hectares of California raspberries were organically managed according to the University of California Agricultural Issues Center. Raspberry prices vary throughout the year, but on average organic raspberries are sold at a price premium. In 2015, the national average retail price of organic raspberries over the entire year was $3.52 per six ounce tray according to the USDA Agricultural Marketing Service. The average retail price of conventional raspberries over the same period was $2.55 per tray. The average California terminal market prices for organic and conventional raspberries were $3.29 and $1.97 per tray, respectively. 16 California raspberries are a major export crop. In 2013, the combined category of raspberry, blackberry, mulberry, and loganberry exports was the twentieth largest export crop category by value in California. Raspberries account for the majority of the production volume and the total value of this category. This California export category was valued at $157 million, and accounted for approximately 85% of total US fresh and processed raspberry, blackberry, mulberry, and loganberry exports. 84% of these exports are received by Canada, 6% by Japan, and 5% by the European Union.The presence of SWD has clearly increased production costs and caused yield losses for California raspberry producers through a variety of channels. However, these studies occurred within one or two years of the first SWD infestations in North America when information on the pest was still sparse and management techniques were rapidly evolving. We can improve on these original estimates now that much more is known about SWD biology, risks, and management. We briefly review these original studies before establishing new estimates of the economic cost of SWD in the California raspberry industry. Walsh et al. 1 and Bolda et al. 6 are the first studies to estimate the economic cost of SWD. These studies utilize yield loss estimates and observations for strawberries, blueberries, raspberries, blackberries, and cherries in California, Oregon, and Washington in conjunction with production data to calculate revenue loss estimates for each state and crop pairing. Walsh et al.1 assume a yield loss of 20% for all the listed crops in these states. As a result, the study estimates a total of $511 million in potential damages annually due to SWD. Bolda et al.6 continue the analysis by assuming the maximum reported yield losses of 40% for blueberries, 50% for blackberries and raspberries, 33% for cherries, and 20% for processing strawberries. The study concludes that potential revenue losses across these states and crops could be as large as $421.5 million given current prices.Goodhue et al. refine these estimates of lost revenue for the California raspberry and strawberry industries by including potential price responses into their estimates. This additional assumption reflects that as the production of raspberries and strawberries decreases, the prices of these products may increase in response. The interaction between production and price is quantified with the inverse own-price elasticity of demand for each crop. The elasticity predicts the percentage change in price of a good in response to a 1% increase in quantity demanded. Drawing upon elasticity estimates established in prior studies, the authors conclude that SWD-induced yield losses could decrease California raspberry and processed strawberry revenues by up to 37% and 20%, respectively. The authors also evaluate the cost of different SWD-targeting insecticide applications and the cost of a specific conventional raspberry pest control program in California’s Central Coast region. The insecticide material and application costs are estimated to be $825.33 per hectare. However, these chemical applications may also provide incidental control of other pests. This implies that the estimate represents an upper bound of the potential chemical control costs associated with SWD.The revenue loss and management cost estimates in these prior studies can be substantially improved using current information about SWD-induced yield losses and management practices. Fruit losses due to SWD and SWD management costs have decreased over time as researchers and producers have developed and implemented better techniques for reducing crop losses.