potato 5-9-12 CLEAN - Vegetableipmasia.org

ORGANIC POTATO PRODUCTION Relative risk: This disease is very common in New York.Management Option Scouting/thresholds Site selection Crop rotation Cover crops Resistant varieties Seed selection Planting Vine killing Sanitation Notes Recommendation for Canker and Black Scurf Record the occurrence and severity of canker. Thresholds have not been established for organic production Heavy, poorly drained soils should be avoided. Minimum three-­‐year rotation to corn or grain crops. Plant a grass or cereal green manure such as a sorghum-­‐sudan grass hybrid or Japanese millet the year before potatoes are grown. One Michigan State study found reduced Rhizoctonia incidence in a potato crop planted after incorporating a spring brassica cover crop. No resistant varieties are available. Plant phytosanitary certified seed (See Section 7.1: Seed sources). Inoculum can be introduced into fields on potato seed tubers. See Section 7: Planting methods. Plant in warm soils and plant shallowly to encourage rapid emergence. Best if soil organic matter is decomposed before planting. Minimize the time tubers stay in the soil after vine death. Inoculum can also be introduced to the fields by contaminated soil. If conditions are cold and wet, potatoes should be planted shallowly or planted deeply and covered shallowly. This encourages rapid emergence and reduces the chance of damage to new sprouts, ‘sprout burn’ 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 12.8 Pesticides Labeled for Management of Canker and Black scurf Class of Compounds Product Name (active ingredient) BIOLOGICALS ActinoGrow (Streptomyces lydicus WYEC 108) Actino-­‐Iron (Streptomyces lydicus WYEC 108) Actinovate AG (Streptomyces lydicus WYEC 108) RootShield WP (Trichoderma harzianum T-­‐22 (KRL-­‐AG2)) str. Serenade Soil (Bacillus subtilis str. QST 713) Product Rate 1-­‐12oz/A drench 2-­‐18oz/100lb seed* 10-­‐15 lb/A (in-­furrow)3-­‐12 oz soil drench 2-­‐18 oz/cwt seed 0.3-­‐3oz/cwt seed 16 – 32 oz PHI (days) REI (hours) Efficacy Comments 0 1 or when sprays have dried ? -­‐ 4 ? Water in after application 0 1 or until solution has dried -­‐ Until sprays have dried *can be applied to seed in a slurry or dry in planter box. ? Use as in furrow/soil drench application. 3 Trichoderma based products effective in 0/4 trials. For use in planter box only. In-­‐furrow spray. 2-­‐6 qts/A 0 4 ? Used as a soil drench or in furrow application. 402012