小麦赤霉病危害损失与防治指标研究

小麦赤霉病是影响河南省小麦产量和质量的主要病害之一.一般年份病情指数每增加1%.产量损失率约增加0.5%;病穗率每增加1.3%.病粒率约增加0.5%.根据防治小麦赤霉病的投入和产出情况.制定出亩产300kg、350kg、400kg不同产量水平麦田的赤霉病防治指标.即病情指数(%)分别为2.3～2.7、1.9～2.3、1.6～2.0;病穗率(%)分别为11.7～12.3、11.2～11.7、10.9～11.4.在赤霉病严重发生年份,防治指标可适当降低.

Studies on the Yield Losses of Wheat Caused by Wheat Scab

This work was carried out during 1987-1988. Field experimemts were distributed at three locations in Henan province. Four cultivars were used as experimental materials and different severity of disease was made by different intensity of field inoculation. The result showed that when the disease index increased by 1%,the yield loss increased by 0. 5%, the percentage of the diseased ear increased by 1.3% and the percentage of diseased grain increased by 0. 5%. The economic threshold of controlling the disease was based upon the yield level of wheat crop. If the yield level ranged at 4. 5,5. 25 and 6. 0 tons per hectare,the disease indices of economic thresholds of controlling were calculated as 2.3%-2. 7%,1. 9%-2. 3% and 1. 6%-2. 6% respectively. The extension of the usage of these economic thresholds was also dicreased.