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玉米是我县主要粮食作物之一,特别是近几年来,发展较快,面积扩大和单产提高的幅度较大,总产占粮食总产的30％。但由于玉米螟的危害,每年都要造成一定程度的损失,一般年份可减产百分之十五到二十。自推广化学农药颗粒剂以来,心叶期危害大大减轻。但近些年来,颗粒剂不能规格化制作,防治效果有所降低,同时穗期螟害显著加重,一九六六年至一九七二年,玉米百杆有虫五百至七百头,雌穗被害及茎秆倒折现象严重,对产量影响很大。
Corn is one of the major grain crops in our county. In recent years, in particular, corn has developed rapidly, its area has been expanded and the yield per hectare has risen sharply, accounting for 30% of the total grain output. However, due to the damage caused by corn borer, each year to a certain degree of loss, the general year can be reduced by 15% to 20%. Since the promotion of chemical pesticide granules, heart-leaf damage greatly reduced. However, in recent years, the granules can not be normalized and the control effect has been reduced. At the same time, the stem borer significantly aggravated during the spike period. From 1996 to 1972, there were 500 to 700 pests per 100 grains of corn, Ear damage and stalk crease serious phenomenon, a great impact on the yield.