棉花密植化学除草不中耕的研究

棉花采用密植化学除草不中耕是当前棉花栽培另一种方法。它比早播、稀植、中耕多次的播种期晚30—40天,但提早拔秆15天左右,前后作物可以不套种。为了发挥群体增产作用,每亩密度为15000—20000株。早打顶,每株留3—4个果枝,主攻伏挑。前期用除草剂灭草,中、后期以密植控草,整个生育期不中耕。经我省连续5年多点试验和大面积示范证实,它可以克服我省3—4月播种时,低温多雨,烂种死苗和深秋低温多雨烂桃或不吐絮等不良气候的影响,能一播全苗,提高棉花品质;能避开前期棉蚜、地老虎和后期第四代棉铃虫的为害;还能调节棉花与小麦、油菜等春收作物及插早稻争季节、争劳力、争土地的矛盾,从而提高了土地利用率,争取粮棉、油棉双丰收。在同一品种,土、肥、水相当的条件下,棉花采用密植与化学除草不中耕相结合,除草效果达75—95%,其产量,一般比当地早播、稀植、多次中耕的增产两成左右。高的每亩产皮棉150—200斤。省工50%左右,降低成本20—30%。

RESEARCH FOR THE NON-INTERTILLAGE OF THE CLOSE-PLANTING COTTEN BY CHEMICAL WEEDING

Cotten was close planted from 1973 to 1977 in our province (the harvesta-ble plants per mu were about 14000).Cotten field was dealt with herbicides before seeding or before imergenee,and not weeded by intertillage during the whole growth duration.As a result,the weeding effeciency of herbicides reach-ed to 75-95%.As compared with control (its harvestable plant per mu were about 4000),the yield of the tested cotten increased by about 20%,and the labour effeciency of the peasants raised by 40-50%.Further more the expense of production decreased by 20-30%.