Antagonistic effect of leguminous green manure crops on Heterodera glycines and the effect of these crops on Pratylenchus penetrans

摘要

The infestation of Heterodera glycines (SCN) (race 1) was observed in 14 leguminous crops tested by pot. When dividing development of infested SCN in the root, percentage of females and cysts was very low (0-1.4 percent) in the following crops. Thatis five species of clover (red clover, crimson clover, persian clover, white clover and alsike clover), alfalfa, Crotalaria spectabilis, resistant soybean (Suzuhime) derived from the Peking line, Crotalaria juncea, blue lupine and wooly-pod vetch. The nematode population in the soil after the cultivation of these crops declined greatly. Field test was carried out at Mukawa SCN (race 1) infested field (120 eggs/g dry soil). The density of SCN eggs declined to about 5 eggs after three months cultivationfrom May 16th of red clover, crimson clover, wooly-pod vetch and resistant soybean (Suzuhime), but they increased the density of Pratylenchus penetrans. The cyst index of susceptible soybean (Suzumaru) as aftercrop of red clover, crimson clover, wooly-pod vetch and resistant soybean (Suzuhime) was lowered. Soybean yield was 130-140 kg/10 a of dry matter after crimson clover, wooly-pod vetch and resistant soybean (Suzuhime), but 80 kg/10 a at red clover, 24 kg/10 a at wild oats (Avena strigosa), 30 kg/10a at susceptible soybean (Suzumaru). Crimson clover, wooly-pod vetch and resistant soybean (Suzuhime) were selected as antagonistic plant of SCN.