油菜菌核病危害损失的初步研究

A PRELIMINARY STUDY ON RAPE SCLEROTIOSE CAUSED BY SCLEROTINIA SCLEROTIORUM TO YIELD LOSSES

本文就油菜菌核病病情、发病期及发病部位与油菜产量损失的相互关系进行了模似研究。结果表明：病斑绕茎度是影响产量的主要因素，其大小与产量损失成正相关，而病斑纵向长度与产量损失无明显相关性；发病期不同产量差异显著，以初花期发病产量损失最重，发病期与产量损失线性相关，可利用线性回归方程对产量损失进行预测；主茎发病部位愈近基部，枝条发病部位愈趋于主茎，单株产量损失率愈高。

This paper is reported that the relationship among disease incidence,growth stages and suffering location to yield losses of rape.The results show that the main factor in effecting yield losses is the ratio of spot cross width to stem girth,which is direct correlation to yield losses.There are no significant correlation between the congitudinal length of spot and yield losses.The yield losses of indivduat plant is differential to suffer at different stages,especially,in primary blossming stage,It is linear correlation between disease stage and rate of yield losses.The yield losses can be predicated by means of linear regression equation.The percentage of yield losses is the highest,if the suffering location is cosed in the base on main stem,and the diseased branches are near to the main stem.