Langston D B, Phipps P M, Stipes R J
Former Graduate Student and Currently Assistant Professor, University of Georgia, Coastal Plain Experiment Station, Tifton 31793.
Professor, Tidewater Agricultural Research and Extension Center, Suffolk, VA 23437.
Plant Dis. 2002 Feb;86(2):118-126. doi: 10.1094/PDIS.2002.86.2.118.
Algorithms were evaluated for computing disease risk and improving the timing of fungicide applications for control of Sclerotinia blight of peanut. Disease risk was calculated by multiplying indices of moisture, soil temperature, vine growth, and canopy density each day, and summing values for the previous 5 days to obtain a 5-day risk index (FDI). After fungicide application, the FDI was reset to zero for 3 weeks. Fluazinam at 0.58 kg a.i./ha applied at FDI 24 or 32 in 1994 and 1995 suppressed disease and increased yield as much as or more than programs of weekly scouting and applying fungicide at the initial onset of disease with additional sprays at 3- to 4-week intervals. The FDI algorithm was also more efficient than calendar sprays at 60, 90, and 120 days after planting (DAP). Environmental and host parameters were expanded in 1996 and 1997 by adding new temperature and new vine growth indices. These parameters along with DAP-dependent thresholds consistently improved the timing of fungicide sprays and disease management when using the FDI algorithm in comparison to weekly scouting or calendar sprays at 60, 90, and 120 DAP.
对用于计算花生菌核病发病风险及优化杀菌剂施药时机的算法进行了评估。通过将每日的湿度、土壤温度、藤蔓生长和冠层密度指数相乘，并对前5天的值求和来计算发病风险，从而得到一个5天风险指数（FDI）。施药后，FDI在3周内重置为零。1994年和1995年，在FDI为24或32时施用0.58千克有效成分/公顷的氟唑菌酰胺，与每周巡查并在病害初发时施药以及每隔3至4周额外喷施的方案相比，能同样有效地抑制病害并提高产量，甚至效果更佳。FDI算法在种植后60、90和120天（DAP）时也比按固定日程施药更高效。1996年和1997年，通过添加新的温度和藤蔓生长指数来扩展环境和寄主参数。与每周巡查或在60、90和120 DAP时按固定日程施药相比，在使用FDI算法时，这些参数以及依赖于DAP的阈值持续优化了杀菌剂喷施的时机和病害管理。
