Effects of maize-soybean intercropping on the occurrence and damage of fall armyworm Spodoptera frugiperda and the yield
To clarify the effect of maize-soybean intercropping on the occurrence and damage of fall ar-myworm,Spodoptera frugiperda,as well as the yield,a study was established during two growing sea-sons in Nanning,Guangxi Zhuang Autonomous Region,in 2023.The experimental treatments included monocultures of maize and soybean,and intercropped systems with two rows of maize and four rows of soybean,and four rows of maize and four rows of soybean.The number of S.frugiperda larvae per 100 plants and maize damage rate were surveyed in the field by direct observation,and yields of maize and soybeans were measured.The results indicated that during the experimental period in 2023,the oc-currence of S.frugiperda was more severe in the second half of the year(September 1st to October 27th)compared to the first half(March 20th to May 15th).Compared to monoculture maize,the num-ber of S.frugiperda larvae per 100 plants in the intercropped systems with two rows of maize and four rows of soybean,and four rows of maize and four rows of soybean decreased by 41.01％and 41.21％,respectively.The maize plant damage rate was also significantly reduced,with land equivalent ratios of 1.35 and 1.26,respectively,in the first half of the year.In the second half of the year,the number of S.frugiperda larvae per 100 plants in the same intercropping systems decreased by 10.11％and 6.82％,re-spectively.There was no significant difference in the maize plant damage rate,and the land equivalent ratios were 1.50 and 1.43,respectively.This study suggested that under relatively low population densi-ties of S.frugiperda,maize-soybean intercropping can alleviate the occurrence and damage of S.frugi-perda.In terms of yield,both intercropping systems with two rows of maize and four rows of soybean,and four rows of maize and four rows of soybean showed increases,with the former demonstrating a greater advantage.
maize-soybean intercroppingSpodoptera frugiperdaoccurrence and damageland equiva-lent ratioyield
万方数据
维普
