【摘要】 1983—1985年,通过定株系统观测,对毛白杨幼苗由锈病造成的生长量损失做了数理分析,提出3个数学模型,可试用于计算不同病情（x）对单株胸径增长量（y）的影响,并可做为研究防治苗圃锈病的经济效益和防治指标的参考。用于1年生养干苗的模型为:y₁=0.2998e^-0.08481x 用于2年生养干苗的模型为:y₂=0.4208e^-0.0457x2 用于3年生养干苗的模型为:y₃=0.7913e^-1.0282x3更多还原

【Abstract】 During 1983-1985,the estimation of growing losses of Populus tomentosa caused by leaf rust in nursery were carried out. Different levels of diseases severity （X） established by spraying fungicide and chest diameter（Y） of young popular trees were investigated.The data obtained were studied by regression analysis. Three holistic models were put forward:（1） The model was used for poplar trees, which had been planted for one year: Y₁=0.2988e_0.0848x1（2）The model was used for poplar trees, which had been planted for two years:Y₂=0.4208e_-0.0457x2（3）The model was used for poplar trees, which had been planted for three years:Y₃=0.7913e_-0.0282x3It is believed that the three equations be beneficial in the disease loss assessment and making disease control management.更多还原