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, is another means of reducing the availability of fruit for SWD to infest. Fallen and damaged fruit are a breeding ground for SWD and other Drosophila species alike. 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,nft system 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.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.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 piece rate 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,hydroponic gutter 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. Cardiovascular diseases are the leading cause of death globally . Major risk factors for developing CVDs include age, biological sex , high blood pressure, smoking, dyslipidemia, and impaired fasting glucose among others . Because these risk factors cluster and interact multiplicatively, the term cardiometabolic disease is often used to describe a grouping of disorders including hypertension, dyslipidemia, impaired glucose and insulin dynamics, and abdominal adiposity that together increase the risk for CVDs as well as type 2 diabetes . Acknowledging that diet quality plays a major role in cardiometabolic disease-free life expectancy , the American Heart Association published Strategic Impact Goals designed to improve cardiometabolic health and reduce related deaths through promotion of healthy behaviors including improvements in diet quality . Whereas exclusive adherence to a healthy diet is ideal for optimizing disease risk and reducing disability-adjusted life years, the potential impact of migrating dietary patterns toward inclusion of key foods containing bioactive compounds should not be underestimated. A large and constantly evolving body of research suggests that dietary bioactives play a key role in human health maintenance as well as disease prevention and mitigation, particularly during the aging process. As such, the US NIH Office of Dietary Supplements has proposed the term bioactives or bioactivefood compounds for use in referring to constituents in foods or dietary supplements other than those needed to meet basic human nutritional needs yet responsible for changes in health status. Among the more commonly studied bioactives is the family of secondary plant metabolites known as flavonoids. In recent years, the nutrition science community has provided evidence elucidating the effects of flavonoids on cardiometabolic health . Such research reports that the health-promoting properties of flavonoids are likely due to a synergistic combination of their antioxidant, antiinflammatory, antimutagenic, and anticarcinogenic properties along with their modulating effects on cellular enzyme functionality . Although there are many subclasses of flavonoids grouped according to chemical structure, flavan- 3-ols—abundantly present in tea, apples, pears, berries, and chocolate/cocoa products—are the most highly consumed flavonoid subclass according to data from the NHANES . As such, the objective of this Expert Panel was to review the available evidence assessing flavan-3-ol intake and cardiometabolic health for development of an intake guideline.The Academy of Nutrition and Dietetics , who were consulted to lead this project, led the process of Expert Panel recruitment. An independent Work Group Selection Subcommittee from the Council of Research led the selection process to ensure appropriate expertise and limit selection bias. An open recruitment message with a link to online application was circulated via stakeholders for experts in the topic area via the Academy and related scientific societies in the field of nutrition . Interested candidates provided conflict-of-interest forms, curriculum vitae, and personal statements indicating interest and qualifications related to the topic. Each candidate was evaluated based on a set of standard predetermined criteria , and candidates with the highest scores were selected for the Expert Panel, with the highest scoring candidate selected for the chair position. A total of 6 members were appointed to develop the guideline. The Expert Panel participated in all steps of the guideline development process, which included reviewing and evaluating the evidence, developing a recommendation statement based on the EtD framework, and writing a manuscript. The Expert Panel and members of the guideline development team met via web meetings for the duration of the project. In the interest of full disclosure, the Expert Panel was required to disclose potential conflicts of interest by completing the Academy of Nutrition and Dietetics Conflict of Interest Form. COIs were updated at the beginning of every meeting.