小麦田不同杂草群落及防除时间对小麦产量的影响
The influence of different weed populations and control time on wheat yield in Shandong

为明确小麦田不同杂草群落及防除时间对小麦产量的影响，于2013-2015连续两年在山东省聊城市高唐县小麦田中设草对照区、禾本科杂草区、阔叶杂草区以及混合杂草自然发生区4种不同杂草群落以及不同的杂草防除时间，测定在不同条件下小麦产量及各项产量构成指标的情况。结果表明，阔叶杂草对小麦产量的影响大于禾本科杂草，冬小麦田杂草的最佳防除时间为4月1日之前，在此期间除草对小麦产量影响均不大，但之后防除或不除草会造成小麦严重减产甚至绝产，2014年4月15日除草可造成在阔叶杂草区和杂草混合生长区的小麦减产30.5%和32.6%，不除草可造成在禾本科杂草区、阔叶杂草区和杂草混生区的小麦减产8.6%、91.4%和94.3%，2015年趋势和2014年一致。从构成小麦产量的3个指标来看，杂草危害主要影响小麦的总穗数，其次为穗粒数，对千粒重影响最小。
To clarify the effects of different weed populations and weed control time on the wheat yield, four treatments of weed free, grass weeds, broadleaf weeds and mixed weeds and different control time were set in Gaotang County, Shandong Province, China in 2013-2015. The wheat yield and index were determined under different conditions. The results showed that the wheat yield damage caused by broadleaf weeds was higher than grass weeds, and the best weed control time was before April 1st, and wheat yield loss with the weed control time later than April 1st, even more serious. The wheat yields reduced by 30.5% and 32.6% in broadleaf weed plots and mixed weed plots controlled on April 15th, 2014, respectively, and 8.6%, 91.4%, 94.3% in grass weed, broadleaf weed and mixed weed plots if no weed control, respectively. The tendency in 2015 was consistent with that of 2014. Moreover, yield loss of wheat mainly affected the total spike number, followed by grain number per spike and 1 000-grain weight.