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一、发生概况1981年南阳地区的菟丝子发发生较轻,但仍较普遍.据调查,南阳、方城、社旗、新野、镇平、邓县等县都有不同程度的发生,危害绝收面积小的几平方米,大的1-2亩.单作危害重,玉米、大豆带状间作为害轻;早熟品种受害轻,晚熟品种受害重;豆种精选好的受害轻或不受害,豆种混有菟丝子种子的受害重;轮作不受害,连作受害重.据观察,大豆菟丝予每年只有一个出苗高峰,即豆苗出齐后的5-9天.菟丝子出苗后
First, the occurrence of Occurrence in 1981 Nanyang area dusky hair less serious, but still more common.According to the survey, Nanyang, Fangcheng, Sheqi, Xinye, Zhenping, Dengxian County and other counties have varying degrees of occurrence, endanger the absolute area Small a few square meters, a large 1-2 acres. Single as endangered, corn, soybeans between the band as the harm light; early maturing varieties suffer from light, late-maturing varieties suffer heavy; beans selected good damage or no harm, Bean mixed with dodder seed victims heavy; rotation does not hurt, even for the victims suffered heavy.It is observed that the soybean reeling silk to only one peak of emergence each year, that bean sprouts came together 5-9 days after the dodder