EFFECT OF NEMATICIDES ON ROOT LESION NEMATODES AND FORAGE LEGUME YIELDS
A field study was made on the effectiveness of seven nematicides in reducing root lesion nematode (Pratylenchus spp.) numbers in soil and roots of alfalfa, red clover, and birdsfoot trefoil. Each of the nematicides significantly reduced the number of nematodes recovered from soil 2 and 14 months after seeding, and from roots 4 and 16 months after seeding. Nematicide treatments significantly increased first cut (August) yields of red clover, alfalfa, and birdsfoot trefoil in the seeding year by 55, 28, and 47%, respectively. Total yields for the seeding year were increased by 22, 22, and 40%, respectively. Sixteen months after seeding, significantly more nematodes were recovered from birdsfoot trefoil roots than from red clover, and more from red clover than from alfalfa. The recovery of Fusarium spp. from rootlets 4 months after seeding was not affected by nematicide treatments; however, Fusarium spp. were recovered less frequently from birdsfoot trefoil than from red clover or alfalfa rootlets.