DIM BOA-Glc levels on the other hand may not be significantly altered as previously shown for ABA treated plants which is consistent with our results. Fv is highly resistant to MBOA and has the ability to detoxify the compound by actively metabolizing it into N- malonamic acid which is nontoxic. Consistent with Fv detoxification of MBOA, the concentration of MBOA tended to inversely track pathogen bio mass. However, this did not hold true at 2x[CO2] between +H2O and -H2O plants which would suggest additional interactive effects of 2x[CO2] and -H2O on benzoxazinoids metabolism. Further research investigating the effects of multiple climate change factors on maize benzoxazinoids and their derivatives in interaction with a pathogen more sensitive to these defense metabolites will be necessary to fully understand the potential implications of the abiotic stress induced changes in maize benzoxazinoid dominated defenses. Although the fumonisin contamination was significantly higher in infected stems under simultaneous conditions of 2x[CO2] and -H2O, the amount of fumonisin per unit Fv biomass was reduced compared to +Fv maize at 1x[CO2]. These data are consistent with previous results indicating that elevated [CO2] compromises the transcriptional response of many of the 9- and 13-lipoxygenase and their signaling products, which have the potential to stimulate mycotoxin production. Even though the transcript levels of LOX genes were not measured in this study, the metabolite analysis supports this notion. The addition of drought did not ameliorate the effects of elevated [CO2] on the influx of fatty acid substrate needed for oxylipin biosynthesis, nor did it negate the dampened accumulation of the 13-LOX oxylipin JA following Fv infection . Nevertheless, even though host-derived mycotoxin stimu lants are potentially still reduced,stackable planters the even larger amount of Fv biomass on maize at 2x[CO2]- H2O was ample to lead to greater fumonisin levels and could therefore be an agriculturally relevant food safety concern.

Considering that the drought treatment imposed in these experiments was specifically designed to account for the physiological changes in water utilization at 2x[CO2], it is possible that, in comparison to a more moderate drought stress treatment at 1x[CO2], the amount of fumonisin contamination would be higher instead of lower. Numerous reports indicate that drought enhances maize susceptibility to Fv and fumonisin; however, in these experiments at 1x[CO2]-H2O plants displayed both less Fv biomass and fumonisin compared to irrigated plants. Since maize utilizes more water at 1x[CO2] and the degree of drought stress was higher , the percentage of water in the stem tissues was significantly less . Therefore, it is likely that this lower water activity was not conducive to fungal growth and reduced Fv biomass and fumonisin production. While normalizing for soil moisture content would provide additional insight into the effects of [CO2] at variable levels of drought, this is beyond the scope of the current manuscript. The difference in soil water content was a consequence of the plant’s physiological response to elevated [CO2] which was a factor being studied and was thus intentionally not controlled in these experiments. Elevated [CO2] has the potential to ameliorate the severity of drought; therefore, it is essential to understand how these abiotic factors will interact and influence Fv infection in comparison to conditions which will not receive this same benefit of water conservation. Timing of infection will likely also play an important role in fumonisin contamination levels as during episodes of drought maize at 2x [CO2] may also provide a more favorable environment for pathogen growth, allowing for a prolonged period of mycotoxin accumulation. Furthermore, while the chamber based studies provide valuable data in understanding the defense response under controlled conditions of biotic stress, there are multiple limitations including light intensity, breadth of spectral wave length, and hindered root establishment. These factors likely contribute to the abiotic stress imposed and influence resource availability and distribution.

Additional laboratory studies coupled with field based free air gas concentration enrichment experiments are needed to determine the trade offs between the photosynthetic advantage of water conservation and increased susceptibility on maize grain productivity during simultaneous conditions of elevated [CO2] and drought. Nonetheless, given the heightened climate change concerns and the potential consequences of our uncertainties for future agricultural maize production, our findings have provided a foundation for additional research necessary for the development of climate resilient mycotoxin control strategies.Horticultural crops provide 60 percent of total farm revenue in California agriculture, and Cali fornia provides 37 percent of the horticultural crop value in the United States. Clearly, these industries comprise an important part of the agricultural economy. This study provides a detailed statistical profile of California’s horticultural crop industries at the farm level, based on a survey of specialty crop growers that was conducted during the spring of 2002. The Risk Management Agency of the United States Department of Agriculture supported the re search, and the California Office of the National Agricultural Statistics Service helped conduct the survey. Specialty crops, also referred to as horticultural crops, include tree and vine crops, vegetables, and ornamental crops. The statistical profile of California’s horticultural farm industries presented here is the most comprehensive ever undertaken for these industries, drawing on survey data collected from approximately one-third of all horticultural crop producers in the state. Specialty crops are diverse. They differ in their product characteristics, production processes, and market environments. Such heterogeneity extends to risk characteristics of the crops and to the ways farmers cope with various risks. As a preliminary step to development of effective risk management tools, it is important to better understand factors that affect these risks. This report is intended to provide such information to help us understand specialty crop industries, the sources of risk, and behavioral risk responses in these industries.

The following summary of results is organized by topic.About 86 percent of the farms surveyed produced primarily orchard and vine crops, 5 percent produced vegetable crops, and 9 percent produced ornamental crops. About 25 percent of the farms were located in coastal areas, 13 percent in the Sacramento Valley, and 47 percent in the San Joaquin Valley. The remaining 15 percent were in the northern mountain areas, the Sierra Nevada, the Southern coast, and the deserts. Average farm size was 203 acres,stacking pots but the median farm comprised only 34 acres. There were relatively few very large farms and many very small farms. The average number of acres per farm varied substantially among the three crop categories: fruits/nuts, vegetables, and ornamental crops. The average land holding by vegetable growers, 1,106 acres, far exceeded the average of 157 acres for fruits/nuts and 200 acres for ornamental crops. These land figures include land planted to secondary crops . When we examined land planted only in primary crops, our data showed that fruit/nut and vegetable farmers held, on average, about 50 percent of their land in primary crops . However, land for ornamental crops, on average, accounted for only 10 percent of the average 200 acres per farm.Crop diversification has long been recognized as an important risk management tool. Our data showed that crop diversification was much less common for orchard farms than for vegetable farms. About 70 percent of fruit/nut farmers were single-crop growers as opposed to 26 per cent for vegetable farms. The scope of diversification also differed. Fruit/nut farmers predominantly diversified their crops with other varieties of fruits and nuts; only 20 per cent of them used crops other than fruits and nuts for diversification. Vegetable farmers, on the other hand, frequently used other crops for diversification; only one-third of the vegetable farms were diversified among only vegetable crops. Our survey also indicated that primary crop acreage increases with crop diversification for both fruit/ nut and vegetable crops. Farms growing five or more vegetables were, on average, four times larger in vegetable acreage than farms growing a single vegetable crop. In California, 6 percent of specialty crop farmers had some organic or transitional-organic land. In terms of crop category, these farms represented 6 percent of orchard farms, 14 percent of vegetable farms, and 4 percent of ornamental crop farms. Our data showed that these farms also engaged in conventional farming and that they devoted, on average, about one-third of their primary crop lands to organic farming. Judging from acreage assigned to primary crops, the farms were about average in acreage for fruit/nut farms but much smaller than average conventional vegetable farms.Marketing is an important component of risk management. Marketing channels vary by product use . Processing crops are delivered in bulk directly to processing plants, whereas fresh-use crops are sent to operations to be sorted, packaged, cooled , and distributed through marketing channels. California producers were highly specialized in terms of use. Most fruit/nut farms produced mainly for processing use and most vegetable farms produced mainly for fresh use . Only 7 per cent of specialty crop farmers supplied both processing and fresh market outlets.

In processed-use markets, contracts played a major role with contracts with a predetermined price being the most prevalent form. In fresh-use markets, grower/shippers, which combine the packing/shipping business with field production under one ownership, provide a form of vertically integrated business. Our survey showed that grower/shippers accounted for 13 percent of vegetable farmers and 3 percent of orchard farmers and that they mainly supply mass merchandisers . The other fresh-market growers tended to use diverse marketing channels, including selling directly to consumers, marketing through cooperatives and independent shippers, and selling directly to commercial buyers. For fresh vegetable markets, “directly to consumers” was the most commonly used outlet , not by volume of production but by number of farms using this marketing channel.We investigated year-to-year yield variations using yield information for the preceding five years. Taking the average of the five annual yields as an individual’s normal yield, we calculated the percent deviation from the normal yield and then arrived at sample mean deviations for sample categories. Our data indicated that annual yield deviated, on average, 15 percent for fruits/nuts and 8 percent for vegetables over the previous five years. For price and profit fluctuations, we elicited information on the range of the highest fluctuation experienced over the same five year period . For both price and profit, the median of the accumulated distribution fell in the 25–49 percent range for fruits/nuts and the 10–24 percent range for vegetables, indicating that prices as well as profits tend to fluctuate less for vegetables than for fruits/nuts. In response to a list of options as the main cause for the lowest profit, “poor yield,” “low market price due to high domestic production,” and “low market price due to imports” were the three most often cited causes for all crops except ornamentals. They accounted for 70 per cent of the responses for fruit/nut and vegetable farmers. For fruit/nut crops, poor yield was the most cited reason for the lowest profit , but for vegetables, low market price due to high production was cited most , followed by low market price due to imports . This underscores the relative importance of production risks for orchard crops and of market risks for vegetable crops.Two sources of risk, adverse temperature and output price fluctuation, were listed as most important; input price fluctuation, pests, and disease were considered to be moderately important. Crop insurance was a preferred risk management tool for orchard and vineyard farmers, and crop diversification was preferred by vegetable and ornamental crop growers. Diversified marketing was reported to be the second most preferred tool for all three crop categories.As expected, their preferences were closely linked to availability. The most available tools were crop insurance for orchard crops and crop diversification for vegetables and ornamental crops . Orchard and vineyard farmers reported relatively limited availability of other risk management tools.About 53 percent of fruit/nut farmers, 31 percent of vegetable farmers, and 13 percent of ornamental crop farmers said they had purchased crop insurance in the preceding five years and most of those farmers had purchased it for all five years Single-peril insurance is mostly offered by private firms, most commonly for damage from frost, rain, and hail. This insurance was purchased by about 20 percent of fruit/nut farmers and about 10 percent of vegetable farmers.