Effect of Root-Knot Nematode Meloidogyne incognita on Okra Variety as Affected by Soil Organic Amendments in Nigerian Ultisol
Ogwudire, V. E. *
Department of Crop Science and Technology, School of Agriculture and Agricultural Technology, Federal University of Technology, PMB 1520, Owerri, Nigeria.
Nwokeji, E. M.
Department of Crop Science and Technology, School of Agriculture and Agricultural Technology, Federal University of Technology, PMB 1520, Owerri, Nigeria.
Nze, E. O.
Department of Crop Science and Technology, School of Agriculture and Agricultural Technology, Federal University of Technology, PMB 1520, Owerri, Nigeria.
Umar, I. F.
Department of Crop Science and Technology, School of Agriculture and Agricultural Technology, Federal University of Technology, PMB 1520, Owerri, Nigeria.
Kanu, C. B.
Department of Crop Science and Technology, School of Agriculture and Agricultural Technology, Federal University of Technology, PMB 1520, Owerri, Nigeria.
Ogbonna, I. C.
Department of Crop Protection and Environmental Biology, Faculty of Agriculture, University of Ibadan, Oyo, Nigeria.
Ezeobioha, K. B.
Department of Crop Science and Technology, School of Agriculture and Agricultural Technology, Federal University of Technology, PMB 1520, Owerri, Nigeria.
Nnadi, K. J.
Department of Crop Science and Technology, School of Agriculture and Agricultural Technology, Federal University of Technology, PMB 1520, Owerri, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
In the absence of sustainable alternatives, farmers have tended to rely on synthetic nematicides for nematode control, despite the cost, environmental safety and health implications often associated with their use. The present study evaluated the effect of the root-knot nematode (Meloidogyne incognita) disease of okra as affected by Okra variety and soil organic amendments. The study was conducted in the screen house using a 2x3x4 factorial arrangement in a Completely Randomized Design with five replications. Results showed that root-knot nematode disease significantly (P=0.05) prolonged the number of days to flower initiation by 4.5 and 3.95 days for NHAe47.4 and Okra-oji respectively. It also reduced significantly fresh fruit weights and 100 dry seed weights of Okra. On the contrary root weight increased significantly. Based on galling severities obtained the test okra cultivars may be grouped thus: Okra-oji (Highly Susceptible), Akupia (Lightly Susceptible) and NHAe47-4 (Rarely Susceptible/tolerant). Poultry manure was most efficacious in controlling the root-knot disease in all Okra cultivars tested. This was followed by swine and farmyard manures. Municipal waste was the least in controlling the root-knot disease on the Okra cultivars. The use of soil organic amendment has proven to be a sustainable alternative to chemical control, it has also shown that organic amendments can release ammonia, and other lethal substances, which have nematicidal properties and are thus vital for nematode control.
Keywords: Infection, nematode, Okra variety, organic amendment, root-knot, susceptible