ABSTRACT

 Petri dish, pot and field experiments were conducted to evaluate the effect of some selected crop residues (Rice husk, Cocoa pod husk, Cassava peel, Saw dust and Groundnut pod husk) on juvenile (J2) mortality and control of root-knot nematode (Meloidogyne spp.) disease on mungbean (Vigna radiata (L)). Experiment one (Effect ofthe Crop Residues, on Juvenile (J2) Mortality ofRoot-Knot Nematode (Meloidogyne Spp), was laid out in a completely randomized design (CRD) with seven treatments replicated three times including the control. The treatments applied were Rice husk, Cocoa pod husk, Cassava peel, Saw dust, Groundnut pod husk and Synthetic nematicide (Carbofuran). Two hundred (200) nematode juveniles were introduced into each ofthe 21 petri dishes. Also, thirty (30) grams of each of the crop residue were applied respectively while carbofuran was applied at 3grams. Numbers of dead larvae were recorded at 24, 48 and 72 hours respectively. Experiment two (Effect of the Crop Residues on Root-Knot Nematode (Meloidogyne Spp.) disease on Mungbean in pot) was a pot experiment laid out on an open field with eight treatments replicated three times including the control. Plants were inoculated with 1000 nematode eggs of Meloidogyne spp., after which treatments were applied as in experiment one above. Experiment three (Effect ofthe Crop Residues on Root-Knot Nematode (Meloidogyne Spp.) disease on Mungbean in Field Trials) was a field experiment conducted during early and late planting season in 2017, laid out in a randomized complete block design (RCBD) with seven treatments replicated three times including the control. Plants were treated with same treatments and rates as in experiment two above. Data collected in pot and field trials included; plant height, number of leaves, number of branches, fresh shoot and root weight, dry shoot weight, number of pods, fresh pod weight, number of seed, weight of seed, number of nodules, nematode population in soil and root and number of galls. Data collected were subjected to analysis of variance (ANOVA) using Genstat Discovery Edition 4. Differences between treatment means were separated using Fisher’s Least Significant Difference (F- LSD) at 5% level of probability. Results obtained revealed that the crop residues compared favourably with carbofuran in growth and yield parameters measured. Plants treated with cocoa pod husk (10.67 and 8.08), cassava peels (9.92 and 9.67) and rice husk (10.33 and 9.67) significantly increased the number of seed per plant compared with the control (6.67 and 3.25) in pot and field trials. Furthermore the result showed that the crop residues caused significant juvenile (J2) mortality and reduced the population of nematodes in soil and root. Plants treated with cassava peels caused higher juvenile (J2) mortality at 24hrs (8.33), 48hrs (9.33) and 72hrs (10.00). Also the crop residues were significantly effective in the control of root-knot nematode disease on mungbean, and as well improved mungbean yield since they were incorporated into the soil as organic amendments. Among all the treatments, saw dust significantly performed better in reducing galling incidence in pot and field trials (2.33 and 1.67) respectively