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ARS Home » Pacific West Area » Salinas, California » Crop Improvement and Protection Research » Research » Research Project #429522

Research Project: Minor Use Pesticide Testing on Vegetables and Sugar Crops

Location: Crop Improvement and Protection Research

2019 Annual Report


1a. Objectives (from AD-416):
Conduct laboratory and field tests to provide residue data needed to establish a tolerance on a specific commodity or to support a crop group tolerance. [NP 304, C2, PS 2A3 and C3, PS 3A2].


1b. Approach (from AD-416):
Research to suppport registrations of minor use pesticides. Apply pesticides according to IR-4 protocol guidelines. Obtain performance data, phytotoxicity, yield and efficacy from treated and untreated field plots. Ship samples to laboratories for residue analyses. Protocols will be employed using appropriate Standard Operating Procedures and conducted under provisions outlined in 40CFR part 160 in accordances with EPA's Laboratory Practice Standards.


3. Progress Report:
Interregional Research Project #4 (IR-4) field trials are being conducted on 13 projects according to approved protocols developed by IR-4 Project Headquarters. Following local good agricultural practices for agricultural production, field testing is in progress on cool season vegetables, herbs and strawberries. Various pesticides are being evaluated in the field test plots on these minor crops. Commercially acceptable minor crops are being grown and sprayed according to the protocols with various test substances using small plot sprayers that simulate commercial application equipment. Crops are frequently monitored for phytotoxicity from application treatments and timing of sprays. Residue samples are collected at harvest and frozen until shipment to a designated analytical laboratory for residue analysis. This season, three field trials on stevia are being conducted with three different fungicides to control Septoria leaf spot, one of the most important pathogens of stevia in the U.S. Stevia is harvested for the leaves and utilized as a sugar substitute, but Septoria can completely defoliate plants prior to harvest, leading to huge yield losses. Currently there are no fungicides registered for stevia, and having products to manage this pathogen is critical to expanding production of this crop in the U.S. Two insecticide trials are being undertaken on summer squash to control various insect pests. One trial will be using cyflumetofen insecticide to control two-spotted spider mites and southern spider mites, which is a new pesticide tolerance request. The other trial is for a pesticide label change and a modified tolerance request with the insecticide, flonicamid, to control plant bugs, stink bugs and thrips on summer squash. Celery transplants will be grown in a greenhouse and drenched with the fungicide ethaboxam to control Pythium root rot on greenhouse seedlings. Two applications will be made approximately 14 days apart, then plants will be properly hardened-off before transplanting in the field. Pythium root rot is a problem in celery transplants grown for the retail market and commercial production fields. The majority of commercial celery is grown from transplants. A trial on basil is planned with the fungicide picarbutrazox to control downy mildew, caused by various species of fungi including members of the genera Pseudoperonospora, Bremia and Peronospora. Downy mildew is a destructive disease and novel chemistries are needed for optimal control in both the greenhouse and field environments. This project is a joint effort with Canada, as they are a key export market for U.S. grown greenhouse and field basil. The Salinas field site will manage approximately 20 to 25 field residue trials yearly on minor use crops over the next five years. The facility will provide treated and untreated samples to the laboratories for residue analysis, while continuing to produce quality scientific data in order to meet Environmental Protection Agency (EPA)'s Good Laboratory Practice requirements for the IR-4 Program. The same milestones will be utilized over the five year period.


4. Accomplishments