环境条件对大豆幼苗疫病发生的影响

Influence of Environmental Conditions upon Development of Phytophthora Root Rot of Soybean Seedling

环境条件下与大豆疫病发生的程度密切相关,其中土壤绝对湿度最为重要,土壤绝对湿度在14 35%～57 12%时,发病率从25%增至100%;空气温度次之,低于10℃时P sojae不能侵染寄主,10～25℃时幼苗疫病发病率从最低升至最高,25℃发病率最高,温度再升,高发病率开始下降;光照强度对该病的发生影响不显著;不同大豆品种存在抗病性差异。

There are close relations between development of Phytophthore Root Rot of Soybean(PRR) and environmental conditions.Soil absolute humidity is the most important factor which affect development of PRR,following is temperature,and influence of light is not markedness.The incidences of PRR change from 25% to 100% when the soil absolute humidity changes from 14.35% to 57.12%.Soybean seedling are not approach by Phytophthora sojae when the temperature is under 10 ℃.The incidences of PRR are from lower to higher when the temperature are from 10 ℃ to 25 ℃,and the incidence is the highest at 25 ℃.The incidence become lower when the temperature are from 25 ℃ to higher.Dominantly cultivars of soybean in Heilongjiang have apparent difference resistance to PRR.