地膜覆盖和除草剂对夏玉米田杂草及玉米生长发育的影响

研究了地膜覆盖和除草剂对夏玉米田杂草和玉米生长发育的影响.结果表明,在玉米3～5叶期施药,药后33 d,杂草数量降至最低,56％2甲4氯钠可湿性粉剂处理的杂草减退率和相对株防效分别比40 g/L烟嘧磺隆油分散制剂提高了11.71百分点和12.65百分点.揭膜后,白色地膜覆盖下杂草的平均鲜重显著低于对照,比对照减少73.25％,相对鲜重防效分别是黑色地膜覆盖、56％2甲4氯钠可湿性粉剂、40 g/L烟嘧磺隆油分散制剂处理的1.12、1.15、1.73倍.地膜覆盖出苗率高且整齐一致,平均株高和叶数比对照高,对玉米的穗粒重、百粒重及其产量有明显的增效作用,以白色地膜覆盖下玉米产量最高,增产率比黑色地膜覆盖的高1.23百分点,比40g/L烟嘧磺隆油分散制剂处理高16.09百分点;而施用56％2甲4氯钠可湿性粉剂严重影响了玉米产量的形成,其产量比对照降低3.09％.

Effect of Plastic Film Mulch and Herbicides on Weeds and Maize Growth in a Summer Field

Experiments were conducted to determine the effect of mulch and herbicides on the growth of weeds and maize in a summer field.Weed density was reduced to a lowest level at 33 days after application of herbicides at 3 ～ 5 leaf growth stage of maize.The application of MCPA-Na 56％ WP provided 11.71％ higher reduction rate and 12.65％ better relative plant effect than that of nicosulfuron 40 g/LOD.When the mulch was removed,the average fresh weight of the weeds present under the white mulch was 73％ lower than that in the control treatment.The white film mulch achieved 1.12,1.15 and 1.75 times of relative fresh weight effects compared to that of treatments of black mulch,MCPA-Na 56％ WP and Nicosulfuron 40 g/LOD,respectively.Under the mulch,crop seedlings emerged normally at a high rate,and developed to have an average height and number of blades higher than those plants in the control treatment.Kernel weight per ear,hundred kernel weight and maize yield also increased significantly.The maize growing under the white mulch was the most productive,and yielded 1.2％ and 16.1％ percentage more than the crop growing under black mulch or treated with nicosulfuron 40 g/LOD,respectively.The application of MCPA-Na 56％ WP decreased crop yield by 3.1％ compared with the relative control treatment.