Management of Meloidogyne incognita in yam-based cropping systems with cover crops

Abstract The effect of intercropping cover crops was with yam was assessed for nematode management both in pot and field conditions in Nigeria. The cover crops were sown with yams in pots containing sterile soil and inoculated with 5000 eggs of Meloidogyne incognita . In the field, each cover crop was separately intercropped with yams inoculated with 10,000 nematodes. From both pot and field experiments, no nematode damage was observed on yam tubers that were intercropped with Aeschynomene histrix , Crotolaria juncea , and Tagetes erecta . Damage in intercropped tubers was reduced by 72.7% with Mucuna pruriens , Centrosema pubescens , and Pueraria phaseoloides and by 58.3% with Stylosanthes guianensis compared to yams planted without cover crops; they also had lower ( p  ≤ 0.05) nematode populations. Cajanus cajan , Lablab purpureus and Vigna unguiculata however, supported high nematode populations and led to nematode damage in intercropped yams. Tubers from M. incognita -inoculated plants were more damaged and lost 42% more weight ( p  ≤ 0.05) following three months of storage than tubers from uninoculated plants. Intercropping yams with selected cover crops can be useful in managing M. incognita without reducing yam yields.