ABSTRACT

The nematicidal effects of Agro-effluents (cowpea, cassava and maize effluents oil palm sludge and neem leaf extract) on root-knot nematode (Meloidogyne incognita) egg hatchability, juvenile mortality and on the management of root-knot nematode population and damage on okra (Abelmochus esculentus (L.) Moench) were investigated in petri dishes, pot and field experiments (April-June and August-October, 2018). The root-knot nematode egg hatchability and juvenile mortality experiment was laid out in a Completely Randomized Design in Petri dishes placed on a laboratory bench with six treatments replicated four  times including the control. Each petri dish contained 30 eggs ml^-1 of the root-knot nematode. The treatments include; cowpea effluent, cassava effluent, maize effluent, oil palm sludge and neem leaf extract. Tap water served as the control. The treatments were applied at the rate of 10 ml respectively. Number of egg hatched and juvenile mortality were observed for 12, 24, 48 and 72 hours. The pot experiment was arranged in a Completely Randomized Design using plastic pots with six treatments replicated four times including the control. Each seedling was inoculated with 1,000 nematode eggs. Similar treatments as egg hatchability and juvenile mortality, in addition to pots without inoculation were used. The treatments were applied at the rate of 10 ml per pot. Data collected included, growth parameters (plant height and number of leaves), pod yield (number of pods, and weight of pods), shoot and root parameters (fresh and dry shoot weight, and fresh root weight) nematode-induced galls and population (number of galls, final soil larva population and number of eggs in roots). The field experiments (the two seasons) were conducted in a land naturally infested with root-knot nematode and were laid out in a Randomized Complete Block Design with six treatments replicated four times, including the control. Similar treatments as in pot experiment, in addition to beds without treatment application were used. The treatments were applied at the rate of 10 ml per plant. Similar data as in the pot experiment, in addition to initial soil larva population were taken.  Proximate composition analysis of the treated and untreated okra pods was done to determine its crude protein, fibre, fat, ash, carbohydrate and moisture content in the laboratory. Upto 0.5g, 3.00g, 3.00g, 1.00g, and 2.00g of the samples were taken, for the analysis of each constituent respectively. The experiments were replicated three times and arranged in a Completely Randomized Design. The data collected in the four experiments were subjected to Analysis of Variance (ANOVA) and means were compared using least significant Difference (LSD) at 5% probability level (P< 0.05) by using computer software “Genstat Dissovery Edition 4”. Results obtained at the end of the experiments was significant between the treatments in most cases, in comparism to the control.