野燕麦对不同小麦品种产量性状的影响及其经济阈值

Influence of Avena Fatua on the Yield Characters of Different Wheat Cultivars and Its Economic Threshold

为给防除小麦田间恶性杂草野燕麦提供依据,采用添加系列试验和模型拟合的方法研究了野燕麦与小麦的竞争。结果表明,随着田间野燕麦密度的增加,小麦有效穗数、穗粒数和产量逐渐降低,而小麦千粒重的变化趋势不明显。模型拟合结果显示,野燕麦密度与小麦有效穗数和产量间的关系以指数模型(y=beax)较好,与穗粒数间的关系以直线模型(y=ax+b)较好,而与小麦产量损失间的关系以对数模型(y=alnx+b)最佳。野燕麦对矮秆小麦品种郑麦9023产量性状的影响大于对高秆品种鄂麦35057的影响。根据小麦的经济危害允许水平,通过拟合的野燕麦密度与小麦产量损失的对数模型估算,当小麦品种为鄂麦35057时,野燕麦人工防除的经济阈值为9.04株.m-2,使用6.9%精噁唑禾草灵水乳剂化学防除的经济阈值为3.77株.m-2;而当小麦品种为郑麦9023时,相应的经济阈值分别为5.85株.m-2和3.32株.m-2。不同小麦品种的生长竞争能力存在较大差异,这可能是导致野燕麦与小麦间的竞争发生变化的原因。

To provide guidance for control of Avena fatua（Wild oat）,a noxious weed in wheat fields,additive series experiment and model fit were adopted to study the competition between A.fatua and two different wheat cultivars.The results showed that the spike number,spike grains number and yield of wheat decreased gradually as A.fatua density increased,but the 1000-grain weight of wheat showed no significant change.The exponential regression model（y=be^ax） was better for fitting the relationship between A.fatua density and spike number or yield of wheat,the linear model（y=ax＋b） was better for fitting the spike grains number,and the logarithmic model（y=alnx＋b） was best for fitting the yield loss of wheat.Influence of A.fatua on dwarf wheat cultivar Zhengmai 9023 was greater than tall wheat cultivar Emai 35057.Based on the economic infestation level of A.fatua and the obtained logarithmic model,for wheat cultivar Emai 35057,the economic threshold of A.fatua was 9.04 plants·m^-2 for manual control and was 3.77 plants·m^-2 for chemical control by fenoxaprop-P-ethyl 69 EW;but for Zhengmai9023,the economic threshold was 5.85 plants·m^-2 and 3.32 plants·m^-2,respectively.Different wheat cultivars have different growing habit and competitive capability,which may result in the change of competition between A.fatua and wheat.