THE ROLE OF SOIL MOISTURE REGIME IN ENHANCING BIOFUMIGATION EFFICACY AGAINST Meloidogyne Incognita (KOFOID ET WHITE) CHITW. ON TOMATO

Abstract

Anaerobic soil disinfestation (ASD), through anaerobical decomposition of organic matter in the soil is currently recommended for the control of soil borne pests including nematodes. A greenhouse trial was conducted aimed to assess the efficacy of different soil moisture regimes i.e. field capacity (FC), saturation (SA) and flooding (FL) with and without forage radish (FR) biomass addition on suppressing of root knotnematodes (Meloidogyne incognita) in tomato plant growing soil. The trial was laid out as 7 treatments in 4 replicates in completely randomized design (CRD) pots. In addition to the six treatments of soil moisture regimes with and without fodder radish, vydate, as synthetic chemical nematicide was used as positive control treatment. However, FC soil moisture regime without fodder radish served as negative control treatment. pH, redox potential (Eh) and oxygen diffusion rate (ODR) were measured in the soil in one-week interval during 4 weeks of fodder radish decomposition period before tomato seedlings (cv. Elysa) transplanting. Root knot nematode population (Meloidogyne incognita), reproductive factor and galling index were determined 12weeks after transplanting. Tomato crop growth parameters including plant length, fresh and dry plant weights and fruit fresh weights were also recorded. Obtained data revealed that both pH, Eh and ODR in the soil during 4 weeks of fodder radish decomposition period dramatically declined under soil flooding with fodder radish green manure treatment. Flooding the soil with fodder radish significantly reduced nematode population, reproductive factor and galling index values. The treatment was comparable to that obtained with vydate application treatment and was finally reflected on improvement of all studied tomato growth attributes.