稻曲病危害损失率测定

本试验选用豫南稻区三个重感稻曲病品种桂朝二号、特青二号和吨稻,按单穗病粒数1粒为一级分级,每级取50穗,与健穗进行比较,计算秕粒率,百穗重损失率和千粒重损失率。经相关分析表明,各品种的秕粒率,百穗重损失率和千粒重损失率都与单穗病粒数有极显著的正相关,而百穗重和千粒重则与其有极显著的负相关。回归分析结果:平均每粒加1个病粒,桂朝二号、特青二号和吨稻的千粒重损失率分别上升0.59％,0.68％,0.82％。桂朝二号、特青一号的单穗病粒数与秕粒率的二条回归直线可以用一个回归系数即2.248。

The Determination of the Loss Rate of Rice False Smut Damage

The three serious susceptible rice false smut varieties in yunan rice areas, Guichao 2, Teqing 2 and Dundao are chosen in this experiment. In accordance with the classification of the number of one ill grain of single ear as a class, taking 50 ears from every class, compare with the healthy one and calculate the blighted grain rate, the loss rate of hundred and of thousand grain weight.As the analysis of correlation show- the blighted grain rate, the loss rate of hundred and of thousand grain weight has signi-ficiant positive correction, whereas the hundred and thousand grain weight has signiciant negative correction.The result of the regression analysis is that as one ill grain weight of Guichao 2 , Teqing 2 , and Dundao gets up 0.5%, 0.68% and 0.82% separatly.The two regression lines of the number of single-ear ill grain and of the blighted grain rate may use the same regression coefficient, i.e. 2.249.