Meloidogyne graminicola infestation in selected Sri Lankan rice varieties, Oryza sativa L.. and nemato-toxic effect of Trichoderma viride to reduce infectivity

Meloidogyne graminicola is a nematode parasite of rice, Oryza sativa L, in some rice growing areas in Sri Lanka. M. graminicola infestation levels in eight rice varieties namely Bg 407, Bg 366, Bg 403, Bg 251, Bg 369, Bg 380, Bg 310, and Bg 745 and nemato-toxic effect of Trichoderma viride against the nematode infectivity in a susceptible rice variety were evaluated in this study. Results revealed that varieties Bg 366 and Bg 251 were susceptible; varieties Bg 407, Bg 369, Bg 380, Bg 310, and Bg 745 were moderately susceptible while Bg 403 was moderately resistant to M. graminicola. There was a significant reduction of root galls (p = 0.000, F = 68.92) and weight of the fresh roots (p = 0.001, F = 12.89) of T. viride treated plants of a susceptible rice variety compared to the untreated tillers of same rice variety. This study concludes that none of the rice varieties tested were totally resistant to M. graminicola infestation, hence, T. viride treatment can be integrated into nematode management practices to reduce the nematode population in susceptible rice varieties.