Grant Information
| Knowledge Area | Subject of Investigation | Field of Science | Percent |
|---|---|---|---|
| 216 - Integrated Pest Management Systems | 1499 - Vegetables, general/other | 1130 - Entomology and acarology | 50% |
| 133 - Pollution Prevention and Mitigation | 320 - Watersheds | 1130 - Entomology and acarology | 10% |
| 133 - Pollution Prevention and Mitigation | 430 - Climate | 1130 - Entomology and acarology | 10% |
| 211 - Insects, Mites, and Other Arthropods Affecting Plants | 1499 - Vegetables, general/other | 1130 - Entomology and acarology | 10% |
| 215 - Biological Control of Pests Affecting Plants | 1430 - Greens and leafy vegetables (includes endive, lettuce, spinach, turnip-greens, celery, rhubarb, parsley, asparagus) | 1130 - Entomology and acarology | 10% |
| 215 - Biological Control of Pests Affecting Plants | 1460 - Tomato | 1130 - Entomology and acarology | 10% |
Until recently, sustainable low input IPM strategies for vegetable production had been widely adopted. However, these recent gains are at immediate risk because of the development of large populations of the potato psyllid and the losses associated with the transmission of a plant pathogen. The U.S. potato industry, a nearly $4 billion dollar crop in 2008, has been devastated by the appearance of this pathogen, known as 'zebra chip'. The insect and pathogen have spread to major production areas across the U.S. The losses are likely to increase as Korea, Argentina, and Brazil have established quarantine restrictions on U.S. potatoes. Tomato growers in Baja California, Mexico lost 85% of their tomatoes in 2001, and growers in San Diego Co, Ca lost 50% of their crops in 2003. In Ontario, Canada, greenhouse tomato growers experienced major losses. The potato psyllid was found in potato fields in Minnesota for the first time in 2007. A recent introduction into New Zealand has resulted in major losses in both peppers and tomatoes. Thus, the problem appears to be increasing in both geographic scope and economic importance. Using established procedures and novel strategies, we will develop new approaches to controlling the pest. These include 'green' approaches and plant resistance, as well as using chemistries selected for low mammalian and environmental toxicity. The benfits will be substantial. Consumers will be subjected to reduced potential pesticide residues on food, farm woirkers will be exposed to less pesticide residue, and growers will produce crops more economically, thus improving their profits. Finally, increased pesticide usage associated with psyllids and other new invasive pests, coupled with the use of ground water supplies contaminated with a variety of pollutants, have resulted in significant contamination of agricultural runoff water from fields. Very few studies have been conducted that investigate the effects of these pollutants on insects of importance in agriculture. Consider the example of selenium (Se). Se naturally enters the food chain through water and accumulates in drainage areas where evaporation concentrates soluble salts. Within the western USA, high Se levels around the Salton Sea and Kesterson National Wildlife Refuge have resulted in symptoms of Se intoxication of animals including lameness, hair loss, developmental retardation, malformation, and death. However these are not just localized problems; approximately 160,000 ha of agricultural land in the San Joaquin Valley of CA are affected by salinity and high water tables, a combination which has been correlated with high Se concentrations in this region. Unfortunately, very little is known regarding the effects of selenium accumulation in plants on the lower part of the food chain such as insects or how to deal sustainably with this problem. The effects are almost certainly greater on lower life forms than on mammals and avians. Additional studies designed to address these pollution problems are necessary to understanding both the impact of pollutants on agriculture and agriculture's effects on critical adjacent habitats.
Outputs: Research on the potato psyllid has allowed us to begin development of area-wide integrated pest management programs. We are investigating new chemistries, resistant plant varieties, and entirely novel new strategies for insect management. Presentations will be made to to scientific societies, growers, and others in California, the USA, and other countries. Publications will be placed in scientific journals and other outlets.
1.1a: After psyllid exposure, the insects will be removed from the test plants and then tested for CLp by qPCR to confirm infection. Statistical analyses will be conducted using ANOVA followed by an appropriate post-hoc test (SAS 2002). 1.1b. The percent of psyllids that are pathogen positive on various species of plants will be calculated. The data will be analyzed with PROC GLM in SAS. 1.1c. Host plants will be sampled from populations at different locations throughout California collected during the completion of objective 1.1b. The percentage data of plants within species containing Ca. Liberibacter psyllarous from each sample location and date will be analyzed with PROC GLM in SAS. 2.1.: Potatoes, tomatoes and peppers will be planted at university field stations in CA. Data and statistical analyses will follow the established protocols of Trumble (1982) and Shelton and Trumble (1990). 2.2. The within-field distributions will be calculated using the data collected in 2.1. Statistical analyses will follow the established procedures of Trumble (1994). 2.3. From 2.1 and 2.2, create an efficient sampling strategy for psyllids (after Brewer and Trumble 1991). Objective 3.1a. Document if the intensive use of imidacloprid, spinosad and spiromesifen has generated resistance. The insecticide LC50 values and the relevant 95% fiducial limits will be determined using Proc Probit procedure in SAS. Objective 3.1b. Costs and economic analyses of the programs will be determined using established techniques (Trumble 1998). Data analysis will be by ANOVA. Objective 3.1c Feeding bioassays will be conducted using methods similar to Liu and Trumble (2004). Behaviors will be analyzed between treatments with ANOVA. Objective 3.2a. Dynamics of natural enemies across time and space will be compared to the phenology of the psyllid in the crops and weeds. Objective 3.3a. Psyllids will be sampled from populations at different locations throughout California collected during the completion of objective 1.1a. Data will be analyzed with PROC GLM in SAS. Objective 3.3b.. This research will be conducted in cooperation with Dr. R. Novy of the USDA in Washington State and Dr. C. Miller at Texas A&M. Statistical analysis will be by ANOVA (see Liu et al. 2006). Objective 3.4. IPM programs will be field validated on the UC field stations. Economic analyses will be conducted using the procedures of Trumble (1998). 4. The influence of environmental pollutants on crop-herbivore relationships will be studied both in the laboratory and in the field. For studies with metalloids, initial research will focus on the the impact of plant accumulation of pollutants on pollination by honey bees. For water pollutants such as selenium, arsenic, and hexavalent chromium, plants will be grown in sand culture. All tests will be analyzed by ANOVA with appropriate transformations or typical non-parametric techniques. Studies on the changes in form and species of pollutants such as Se and arsenic as they move through crop plant and insect systems will be determined using commercial labs, the new spectrometer in Environmental Sciences, and with the Stanford Synchrotron (after Vickerman et al 2004).
Target Audience
Target audiences include scientists and growers. Many presentations were were provided for growers and scientists in California, Idaho, Oregon, Utah, Illinois, and Washington, D.C. Trumble also participated in radio interviews (NPR) andnewspaper interviews. The pollution studies were reported in newspapers and radio. All of these presentations were designed to inform key people (scientists and growers) and to modify behaviors to help minimize problems.
Changes / Problems
Nothing Reported
Training & Professional Development
Deborah De La Riva, Ning Di, Kai Zhang and Marcus Pennington were graduate students in the Trumble lab. Issac Esquival, Christopher Tran, and Haley Drew were undergraduates being trained in various aspects of the research project. K. Hladun and S. Prager were post doctoral scientists in the Trumble lab and developed many new skills applicable across the STEM fields
Dissemination Streams
The primary outlet has been journal articles. We have also given numerous presentations to scientists, grower groups, beekeepers, and extension personnel. As part of the outrearch to lay people, Trumble has appeared in NPR news discussing the effects and control of the potato psyllid.
Next Reporting Steps
Nothing Reported