potato 5-9-12 CLEAN - Vegetableipmasia.org

ORGANIC POTATO PRODUCTION Management Option Recommendation for Colorado Potato Beetle After July 15 Summer Adults (try to minimize the number of larvae surviving to adulthood and avoid treating this stage. Remember that potatoes can tolerate 10-­‐15% damage without yield loss) 2nd Larval Generation (Do not apply Entrust Naturalyte Insect Control to both generations of larvae; an azadirachtin product may be a useful alternative. Late season applications of Mycotrol-­‐O (Beauveria bassiana) may help reduce overwintering populations by causing mortality to pupae and adults in the soil.) To minimize selection for resistance, only use insecticides when needed; use the minimum dosage necessary to provide control; rotate insecticides of different chemical classes and modes of action; create refuges untreated by insecticides where susceptible populations can survive to mate with resistant individuals and dilute the frequency of resistant genes in pest populations. Natural enemies Resistant varieties Crop rotation Site selection Planting Flaming Vacuum/leaf blower Trap strips & trap tubers Naturally-­‐occurring predators, parasitoids, and pathogens help suppress infestations. Use Reference 94 or Cornell’s Biological Control: A Guide to Natural Enemies in North America (Reference 95) to identify natural enemies. Elba, Prince Hairy and King Harry are resistant to CPB's. Varieties that mature in 75-­‐88 days and thus avoid peak CPB infestations include: Caribe, Norland, Redsen, Sunrise, Superior and Yukon Gold. One year rotation to non-­‐host crops such as small grains or corn can result in greater than 90 percent reduction of early-­‐season adult infestation. Other non-­‐hosts to add in rotation include crucifers and forage crops. Avoid tomatoes, eggplants, and other species belonging to the solanaceae family. Rotation is most effective when large blocks are rotated on a farm or coordinated among adjacent farms. On diversified vegetable farms, rotate tomatoes, potatoes, and eggplant as a block. Minimize the presence of volunteer potatoes in rotational crops by avoiding fall plowing, leaving the tubers on the surface to freeze. Plant slow-­emerging or late-­‐season varieties to fields that did not have potatoes the previous year. Avoid planting potatoes near fields where late-­‐season cultivars with high CPB populations were grown the previous year. Plants that are strong and well established before CPB attack will better withstand feeding damage. Planting as early as possible and covering as shallowly as possible will give plants a head start. Growers in the most northern regions of New York avoid CPB by planting mid to late June; yields are somewhat reduced but they find the trade off worthwhile. Adult CPB's overwinter in hedgerows and wooded areas adjacent to potato fields. Flaming is most effective when used around the borders (the outside eight to 16 rows) of the field. However, in the case of widespread colonization by adults, flaming is more successful when used throughout the field. The most effective time to use a propane flamer is from plant emergence until the plants reach six inches in height. Best control is achieved on warm, sunny days with little wind when adults are actively feeding in the upper foliage. Flaming is ineffective when done in the early morning, late evening, or on cool, cloudy days when adults are in the lower portion of the plant or near the soil level. Burners should be operated eight to ten inches above the soil at four to six miles per hour. Plant injury from flaming is minimal and does not reduce yields. See Reference 99 for videotapes that detail flame weeding. Adult beetles can be removed from trap crop using a retail leaf blower (many brands can be operated in reverse as vacuums). This practice may not be advisable when pathogens like powdery mildew and gray mold are present and might be spread by the vacuum. Early season: Plant strips of a fast-­‐emerging early variety along the edges of the field as early as weather and soil conditions will allow. Cover seed shallowly to promote rapid emergence. The trap crop should emerge before the main crop so trap plants are larger and able to withstand feeding and so sufficient foliage remains 612012