Hamm Philip B, Clough George H
Extension Plant Pathologist, Department of Botany and Plant Pathology.
Research Horticulturist, Department of Horticulture, Hermiston Agricultural Research and Extension Center, Oregon State University, P.O. Box 105, Hermiston 97838.
Plant Dis. 1999 May;83(5):441-444. doi: 10.1094/PDIS.1999.83.5.441.
The effect of application method by aircraft (fixed wing), ground, and chemigation on deposition of chlorothalonil in a potato canopy was compared over 2 years. Initial chlorothalonil deposition was greatest with ground application, less by aircraft, and least with chemigation. After application by aircraft or ground, the upper canopy had more chlorothalonil than the middle, and the lower canopy had the least. With chemigation, the upper canopy also had more chlorothalonil, but amounts in the lower and middle canopy were similar. Redistribution occurred with time as material from the upper canopy moved downward. With a 9-day application frequency using ground or aircraft methods, residue levels throughout the treated potato canopy were maintained, even if distribution of the fungicide within the canopy was poor from the initial application. With chemigation, low initial chlorothalonil levels were further decreased due to redistribution, increasing the likelihood that levels could fall below that which may be needed to adequately control late blight, particularly beyond 7 days after application.
在两年时间里，比较了通过飞机（固定翼）、地面和化学灌溉这三种施用方式对百菌清在马铃薯冠层中沉积的影响。最初，百菌清的沉积量以地面施用最大，飞机施用较少，化学灌溉最少。飞机或地面施用后，冠层上部的百菌清含量高于中部，冠层下部最少。采用化学灌溉时，冠层上部的百菌清含量也较多，但下部和中部冠层的含量相似。随着时间推移，由于冠层上部的物质向下移动，发生了再分配。采用地面或飞机施用方法，以9天为一个施用频率，即使最初施用时杀菌剂在冠层内分布不佳，整个处理过的马铃薯冠层中的残留水平仍能维持。采用化学灌溉时，由于再分配，最初较低的百菌清水平进一步降低，增加了含量可能降至不足以充分控制晚疫病所需水平以下的可能性，尤其是在施用7天之后。
