Studies of the optimum stage for purple stain control in soybean seed

Studies of the optimum stage for purple stain control in soybean seed

1986

A:PS

The objective of the study was to detect the optimum growth stages of soybean [Glycine max (L.) Merr] for controlling purple stain [Cercospora kikuuchii] and its side effect ondecay of pods and seeds. The purple stain was easily induced by frequent drizzling rain at spring and summer crops in Hualien Area. Soybean cultivar Hualien No.1 was planted at two locations (Jui-sui and Yu-Li, Hualien) in spring crop 1985. Fungicide benomyl W.P. (50%) was diluted 1,000 x and sprayed at different soybean growth stages. Weather conditions during the late stage of soybean growth were suitable for purple stain development under higher temperature and humidity in this period. The results indicated that spraying fungicide benomyl W.P. (50%) from V4 to R6 stage at two week interval could control the purple stain disease effectively (infection rate 2.17%, average) spraying at R2 stage was also effective to control purple stain disease (infection rate 2.56%, average). There was no significantly difference between those two treatments. This suggesting that the suitable and economical control stage for soybean purple stain on soybean seeds may be at R2 stage. In addition to this stage, spraying at the R6 stage may reduce the rain damage in case of the late stage of soybean growth under rainy condition. [AS]

v.2:87-91, HUALIEN DISTRICT AGRICULTURAL IMPROVEMENT STATION, BULLETIN

Research > Published Articles