Sustainable management of nematodes infestation of paddy cultivation in Sri Lanka

Abstract

The rice root-nematode Hirschmanniella oryzae, and rice root-knot nematode, Meloidogyne graminicola have emerged as a major threat to rice cultivation. Therefore, the management of nematodes is highly essential for reducing severe damages in rice cultivation. A pre-tested questionnaire survey was conducted in five selected districts. Farmers were selected from farmer communities in each site by using a simple random sampling method (n=150) and, evaluated the effectiveness of new molecules of nematicide and non-chemical management package against nematode in a field experiment. The treatments were Abamectin 0.5% GR with three different dosages, poultry manure, paddy husk, and untreated control with three replicates. Area of 50 m2 each plot arranged in a Randomized Complete Block Design. The number of nematodes in soil, root-knot percentage, and yield data were recorded. The survey revealed that farmers in Mahaweli Systems B and C suffered from yield loss due to nematode attacks. The experiment results indicated that Abamectin 0.5% GR is effective for managing nematodes irrespectively of the dosage. Moreover, the application of poultry manure and paddy husk reduced nematodes from21/20g soil to 6/20g. The pilot trial indicated that there was no significant difference among Abemactin and organic manure applied fields in both nematode count and final yield. Therefore, it can be suggested, the application of poultry manure and paddy husk is a cost-effective, environmentally friendly method for controlling nematodes in the rice field. However, further large scale adaptive trials are needed to confirm and develop the well-adapted, non-chemical package against nematodes in rice fields.