Weed Management in No-till Corn in Wheat-corn Double Cropping System in North China

摘要

Weed management system has been studied from 1996 to 2005 which was suitable to no-till corn in wheat-corn double cropping in north China. Comparing to traditional tillage, weeds emerged earlier than corn and most of them were above 3-4 leave stages before corn emerged in zero-till corn field, furthermore perennial weeds increase after several years of zero till practice, that makes weed control more difficult. Wheat stubble mulching before corn planted showed some weed suppression in wheat-corn double cropping system both because of the physical force and the allelopathic effect of the straw. Some other methods as increasing wheat seeding rates and decreasing wheat row spacing also helped weed management. Wheat stubble mulching and increasing wheat seeding rate connected with herbicide rate, the reduced rate of atrazine [6-chloro-N-ethyl-N'-(1-methymethyl)-1,2,5-