Ruben M. Gapasin, Sally A. Miller, and C. V. Sanchez
Department of Plant Protection,
Leyte State University. Visca, Baybal, Leyte 6521-A
Department of Plant Pathology, Ohio State University,
1680 Madison Avenue, Wooster, OH 44692-44096, USA
http://doi.org/10.57043/transnastphl.2000.5400
Abstract
A microplant experiment with the following treatments: Tagetes sp., two species of Crotonaria (C. ileana and C. mucronata), rice, and fallow, was conducted to determine the effects of Tagetes and Crotonaria plants on the population and development of the rice root-knot nematode, Meloidogyne graminicola. In the two trials conducted, it was observed that no galls were formed on the roots of Tagetes and Crotonaria plants 60 and 90 days after soil infestation. The rice plants, however, had a root gall count of 305.70 at harvest (90 days). Onion grown on the plots planted previously with Tagetes and Crotonaria did not show root galls. However, galls were observed in onions planted in microplots previously planted with rice. Fresh weight of onions was higher in Tagetes and Crotonaria-treated plots compared to the plots planted with rice and the clean fallow treatments. However, differences were insignificant. This could be due to the nematode control and the added fertility when the biomass of these plants was incorporated into the soil before the onions were planted. Rice planted in these treatments showed significant reduction in the number of galls and nematode density in the soil after 60 days. These results showed that planting Tagetes sp. or Crotonaria spp. in nematode-infested soil is effective and feasible in managing the rice root-knot nematode.