不同栽培密度对大豆菌核病病情指数的影响

Effects of Different Planting Densities on Soybean Sclerotinia Stem Rot Disease Index

为明确不同大豆栽培密度下菌核病的病情指数及主要影响因子之间的相关性,于2014年设3个密度处理,分别为:25万株/hm2、30万株/hm2、35万株/hm2,在大豆花期测定田间平均土壤湿度、平均土壤温度、茎秆强度、茎秆粗度、菌核子囊盘萌发个数5个影响因子及8月末大豆菌核病病情指数,采用通径分析的方法分析这些因子之间的关系。结果表明:大豆密植尽管增产,但病情指数提高了,其主要原因是茎秆强度的减弱及子囊盘萌发个数的增多导致了菌核病发生严重,以后在密植的生产田中如果田间子囊盘萌发过多,应对菌核病多加注意。

The study aims to determine the correlation between the disease index of Sclerotinia sclerotiorumand the main influencing factors of different soybean planting densities. The test set up 3 density treatments in2014, 25×104strains /hm2, 30×104strains /hm2 and 35×104strains /hm2. The average soil moisture, average soiltemperature, stem strength, stem diameter, germination number of sclerotium apothecium and the Sclerotinia sclerotiorum disease index were investigated at the end of August. The path analysis was used to analyze theSclerotinia sclerotiorum index and data processed. The results showed that, although the production increasedunder high density planting of soybean, the disease index also increased. The main reason was the weakeningof stem strength and the increase of germination number of apothecium, which led to severe occurrence ofSclerotinia sclerotiorum. In the future, close attention should be paid to Sclerotinia sclerotiorum in case of largegermination amount of apothecium in high density planting of soybean