玉米丝黑穗病发病条件的研究

Study on Inducing Condition of Maize Head Smut

试验主要研究土壤温度、湿度及播种期与玉米丝黑病发生的关系。结果表明,土壤温度为21℃,玉米丝黑穗的发病率最高为31.3%,17℃低温下发病率为10.9%～16.7%,温度在24℃时,发病率为3.7%～4.8%。从湿度对发病率的影响看,土壤含水量与病害侵染发病有较明显的关系。土壤湿度为15%时利于孢子萌发与侵染,发病率为31.1%,湿度为10%或20%时发病率仅为3.7%～8.8%,说明干旱与高湿条件下均不利于病菌孢子萌发,湿度是决定发病程度的主导因素。早播病害重,晚播病害轻,但玉米产量低,因此提倡适时播种。

The relationship of soil temperature, soil humidity, seeding time and occurrence of maize head smut were studied. The results showed that the disease incidence of maize head smut was 31.3% when soil temperature was 24%. It was 10.9% - 16.7% and 3.7% -4.8% when soil temperature was 21℃ and 17% respectively. Soil moisture content was related to disease infection obviously. 15% soil humidity was suitable for spore germination and infection, the disease incidence was 31.1%. When soil water content was 10% and 20%, the disease incidence was 3.7% and 8.8% respectively. Drought and high moisture is not good for spore germination and infection. Humidity is the main reason for disease incidence of maize head smut. Early sowing cause severe disease. Late sowing can reduce disease but the yield is lower. Suitable seeding time is advocated.