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为明确紫茎泽兰Eupatorium adenophorum Spreng在棉田中的经济危害允许水平和经济阈值,采用添加系列试验和模型拟合的方法,在田间条件下研究紫茎泽兰不同密度对棉花的生长性状及产量的影响。在紫茎泽兰的竞争干扰下,棉花果枝数和单株铃数均随着紫茎泽兰密度的增加而逐渐降低。当紫茎泽兰密度达到60株/m2时,棉花果枝数和单株铃数较无紫茎泽兰对照分别减少了22.1%和57.2%,同时棉花皮棉产量损失率也达到57.2%。棉田田间透光率也随紫茎泽兰密度的增加而降低,当紫茎泽兰密度为60株/m2时,其透光率仅为3.5%。幂函数模型y=3.049x1.031能较好地拟合紫茎泽兰密度(x)与棉花产量损失率(y)间的关系。棉田采用人工除草和41%草甘膦异丙胺盐水剂对紫茎泽兰进行防除时,紫茎泽兰的经济危害允许水平分别为8.42%、1.06%,经济阈值则分别为2.68、0.36株/m2。
In order to clarify the permissible economic level and economic threshold of Eupatorium adenophorum Spreng in cotton field, the effects of different density of Eupatorium adenophorum on the growth and yield of cotton were studied under field conditions by adding series of experiments and model fitting methods Impact. Under the competition of Eupatorium adenophorum, the numbers of cotton fruit branches and bolls per plant decreased with the increase of the density of Eupatorium adenophorum. When the density of Eupatorium adenophorum reached 60 plants / m2, the numbers of fruit branches and bolls per plant were decreased by 22.1% and 57.2% respectively compared with those without Eupatorium adenophorum, and the yield loss rate of cotton lint also reached 57.2%. The transmissivity of cotton fields also decreased with the increase of the density of E. adenophorum. When the density of E. adenophorum was 60 plants / m2, the light transmittance was only 3.5%. The power function model y = 3.049x1.031 can well fit the relationship between the density (x) of Eupatorium adenophorum and the yield loss rate (y) of cotton. In cotton field, the economic hazard of Eupatorium adenophorum was 8.42% and 1.06% when artificial weeding and 41% glyphosate isopropylamine salt were used as control. The economic thresholds were 2.68,0.36 plants / m2.