油菜菌核病灾变特点及其综防技术的研究

Studies on the Relationship between Rape Flowering and Control Time of Rape Sclerotiose

应用微机组建了油菜菌核病的预测预报模型,1997～2001年预报准确率达95%;当油菜开花率10%～30%,即1次分枝开花株率50%～100%时,花瓣保湿培养带菌率最高,是菌核病菌侵染花瓣主要时期,也是药剂防治的关键时期;菌核病防治最佳适期为主茎开花株率95%～100%至1次分枝开花株率95%～100%,适期用22%增效多菌灵可湿性粉剂2250g/hm2防治1次,防效达70%左右,保产15%以上,隔5～7d再用药1次,防病效果更佳。

The relationship between rape flowering and control time of rape sclerotiose ( Sclerotinia sclerotiorum) was studied.When percentage of rape plant flower came up to10%～30%,i.e,.the percentage of plant first branch flowered was50%～100%,the percentage of rape petals with fungus,which were confirmed under high humidity,was the highest during the1st to2nd ten-day period of April.Therefore this period was the key stage of infection and chemical control for rape sclerotiorum.The best spraying time to control rape sclerotiorum falled in the period from rape stems of80%～100%with flowers to the1st branch of95%～100%with flowers.the effect of kejumlin(carbendazim+borid fertilizer)at2.25kg/hm 2 were70%on disease-control and15%of yield-protecting respectively.Another spray should be used after5～7days to get better control results.