potato 5-9-12 CLEAN - Vegetableipmasia.org

ORGANIC POTATO PRODUCTION Table 12.8 Pesticides Labeled for Management of Canker and Black scurf Class of Compounds Product Name (active ingredient) Product Rate PHI (days) REI (hours) Efficacy Comments SoilGard (Gliocladium virens str. GL-­‐21) 2 – 10 lbs 0 Until sprays have dried ? Apply in 50 – 100 gallons of water as a band drench in-­furrow.Taegro Biofungicide (Bacillus subtilis var. amyloliquefaciens str. FZB24) 3.5 fl oz/ 100 gal 3 tsp/gallon of water 2.6 oz/100 gallons of water for 2 acres -­‐ 24 ? As a drench. As a tuber treatment. Dip tubers for 10 to 30 minutes before planting. For best results, make two or three applications spaced one week apart. Apply over furrow at time of planting. For best results make 2 or 3 applications one week apart. T-­‐22 HC (Trichoderma harzianum) OTHER PERpose Plus (hydrogen peroxide/dioxide) 0.5-­‐2 oz/cwt -­‐ 0 3 Trichoderma based products effective in 0/4 trials. For suppression of black scurf. Not effective in cool and wet soils. 1 fl oz/Gal (initial/curative) 0.25-­‐0.33 fl oz/gal (weekly/preventative) -­‐ 1 (interior); until dry (field) ? For initial or curative use, apply higher rate for 1 to 3 consecutive days. Then follow with weekly/preventative treatment. For weekly or preventative treatments, apply lower rate every five to seven days. At first signs of disease, use curative rate then resume weekly preventative treatment. 59B PHI = pre-­‐harvest interval, REI = restricted entry interval. -­‐ = pre-­‐harvest interval isn't specified on label. Efficacy: 1-­‐ effective in half or more of recent university trials, 2-­‐ effective in less than half of recent university trials, 3-­‐not effective in any known trials, ?-­‐ not reviewed or no research available 12.9 Botrytis Vine Rot, Botrytis cinereaTime for concern: Growing season, especially under wet conditions and prolific vine growth.Key characteristics: This fungus infects dead tissue and can be seen as a fuzzy, gray growth on dead blossoms or senescentleaves. It is sometimes mistaken for late blight. Under wet conditions and when vine growth is lush, the fungus may move intothe stem tissue. The stem rot is initially wet and slimy. The fungus sporulates on infected tissue and produces a dense, gray tooff-white growth. See Canada HUfact sheetUH (Reference 70).Relative Risk: Occurs sporadically and usually does not result in significant yield loss.Management Option Scouting/thresholds Site selection Resistant varieties Crop rotation, Seed selection, Post-­harvest, and Sanitation Recommendation for Botrytis Vine Rot Record the occurrence and severity of Botrytis vine rot if it will cause disease problems within the crop rotation. Thresholds have not been established for organic production Avoid planting in fields with soils that drain poorly. Avoid areas where foliage remains wet from dew for long periods. Fields surrounded by trees that shade and slow air movement, or those remaining damp late into the morning are at higher risk. No resistant varieties are available. These are not currently viable management options. Notes Nitrogen rates that result in excess vine growth aggravate this disease. 412012