A New Control Method of Soybean Cyst Nematode Using Animal Feces

Summary

We observed strong attachment of soybean cyst nematodes (SCN, Heterodera glycines Ichinohe) to soybean roots when seeds were sown soon after application of dried cattle feces (DCF) to the soil. The increase in the attachment of SCN seemed not to be related to changes in soil condition or in crop growth. Similar accelerating effects were found in other animal fecal treatments in spite of an interaction with inorganic nitrogen contained in animal feces. Moreover, increase in the number of second-stage juveniles was observed regardless of soybean plant presence or absence. Although the active substance has not been identified, hydrophobic extracts from DCF showed superior effects to intact DCF. Delaying the time of sowing of soybean seed until after DCF application reduced the number of female adults on soybean roots because of starvation. In addition, DCF application combined with a delayed sowing time of more than 30 days reduced the density of cysts remaining in the soil by 80% of that of chemical fertilizer treated plots. Although the yield reduction caused by nematode injury was alleviated with DCF application, the application of animal feces in the integrated management of SCN should be carried out together with crop rotation and resistant cultivars, especially in soil severely infested by SCN.