potato 5-9-12 CLEAN - Vegetableipmasia.org

ORGANIC POTATO PRODUCTION Management Option Site selection Resistant varieties Seed selection/treatment Mulches Natural enemies Yellow sticky traps and tape Water-­‐pan traps Floating row covers Vacuum/leaf blower Harvest Sanitation Note(s) Recommendation for Aphids Avoid planting fields immediately downwind of any barrier. Hedgerows, wood lots, or hilly terrain reduce wind velocity and increase the number of dispersing aphids falling into fields. Although all currently available potato cultivars are susceptible to infection by the potato leaf roll virus (PLRV), many cultivars are resistant to the manifestation of virus infection (net necrosis) in tubers. Plant phytosanitary certified seed. Aphids are repelled by ultra violet light. Reflective mulches have been effective in limiting virus transmission by winged migrant aphids. Naturally occurring predators, parasitoids, and pathogens help suppress infestations. Use Reference 94 or Cornell’s Guide to Natural Enemies (Reference 95) to identify natural enemies. Traps should be located away from tree lines and tall weeds where they might be obscured and should be at least 12 inches above the plant canopy. Mount traps vertically along the edges of the field by stapling to a wooden stake. Traps should be located away from tree lines and tall weeds where they might be obscured and should be at least 12 inches above the plant canopy. Any watertight container holding a minimum of one gallon of water with a minimum diameter of twelve inches can be used. If metal containers are used, they must be painted a deep yellow. The trap must be equipped with an overflow for rainwater by cutting a circular hole one inch in diameter in the side of the pan about two inches below the rim. A small piece of window screen should be cemented over the hole to retain aphids when rainwater raises the level of water in the pan. Fill the pan with several inches of water, several drops of liquid dishwashing detergent, and one teaspoon of disinfectant (See Section 10.3: Storage Facility Sanitation) Don’t use floating row covers on areas where emerging insects from last year will be trapped. Aphids can be vacuumed from leaves using a leaf blower operated for suction. This practice may not be advisable when pathogens like powdery mildew and gray mold are present and might be spread by the vacuum. Vine kill and harvest the crop as early as possible to minimize vulnerability to late-­‐season aphid colonization and virus infection. Maintain effective management of weeds in and on the margins of fields. Eliminate volunteer plants and rogue diseased plants. Aphid populations may decline rapidly during periods of heavy rainfall. Insecticides applied for leafhoppers may also suppress aphids. 1 Tuber initiation and bulking coincides with the period following flowering for many cultivars At the time this guide was produced, the following materials were labeled in New York State for managing this pest and were allowable for organic production. Listing a pest on a pesticide label does not assure the pesticide’s effectiveness. The registration status of pesticides can and does change. Pesticides must be currently registered with the New York State Department of Environmental Conservation (DEC) to be used legally in NY. Those pesticides meeting requirements in EPA Ruling 40 CFR Part 152.25(b) (also known as 25(b) pesticides) do not require registration. Current NY pesticide registrations can be checked on the Pesticide Product, Ingredient, and Manufacturer System (PIMS website) http://pims.psur.cornell.edu/ (Reference 3). ALWAYS CHECK WITH YOUR CERTIFIER before using a new product. Table 15.2 Pesticides Labeled for Management of Aphids Class of Compounds Product Name (active ingredient) BIOLOGICALS Product Rate PHI (days) REI (hours) Efficacy Comments Mycotrol O 1/4 – 1 qt/A Up to day of 4 2 Beauveria products effective in 2/7 trials. Foliage contact 652012