苗前与苗后除草剂配施对白菜型冬油菜田间杂草防效及产量的影响OA

Aiming at the problems such as long growth cycle of Brassia campestris L.,high cost of artificial weeding,and lack of effective weeds control technology,the main local winter rape with strong resistance to cold(Tianyou No.4)was selected as the experimental materials.Common pre-seedling herbicides and post-seedling herbicides were selected as the experimental materials,and 3 different treatment gradients were set respectively.Using clean water as control,a total of 16 different combinations were set.Field trials were conducted in 2017 and 2018 to explore the effects of pre-and post-emergence herbicides on weeds control efficiency and yield of winter rapeseed.The results showed that,the total plant control effect and the total fresh weight control effect of single pre-seedling herbicide application was 40.63% and 51.64%.The total plant control effect and the total fresh weight control effect of single post-seedling herbicide was 60.94% and 50.75%.The total plant con-trol effect and the total fresh weight control effect of combined application was 62.33% and 57.23%.Compared with the pre-seedling herbicide application alone,the total plant control effect and fresh weight control effect of co-application were increased by 21.70 and 5.59 percentage points,respectively.Compared with the post-seedling herbicide application alone,the total plant control effect and fresh weight control effect of co-application were increased by 1.39 and 6.48 percentage points,respectively.In terms of yield,the average grain yield of sole pre-herbicide increased by 61.91% with 642.32 kg/hm2 higher than the control.Similarly,average yield of sole post-herbicide increased by 59.41% with 616.42 kg/hm2 higher than the control,and co-application increased by 35.52% which was 368.52 kg/hm2 higher than the control.The high-est yield of sole and co-application treatments were R3 O0 and R3 O2 which significantly increased by 108.22% with 1 122.78 kg/hm2 added and increased by 86.43% with 896.78 kg/hm2 higher than the control,respectively.Therefore,according to weed density in the field of winter rape,the application of pre-seedling herbicide R3 alone or R3 combined with post-seedling herbicide O2 could be selected to achieve the most efficient weed control effect and the most significant increase in rapeseed yield.