Tolerance indicators and responses of rice cultivars to infestation by the African rice gall midge, Orseolia oryzivora

Abstract

The mechanisms and host plant responses that are indicative of tolerance to the African rice gall midge, Orseolia oryzivora Harris & Gagne were investigated in four promising donor rice cultivars, Cisadane, Bw 348-1, Tox 4093-17-1 and ITA 306 (local check), in a screen house at the International Institute of Tropical Agriculture (IITA), Ibadan, Nigeria. Results indicated that Cisadane was tolerant to infestations on the basis of higher (P<0.05) percentage seedling survival, production of significantly higher number of fertile tillers, productive panicles and significantly higher grain yield per infested plant than the control. Both single infestation at one larva per plant and adult infestation once at 14 days after seeding were positively correlated to higher fertile tiller production per infested plant (at 80 days after transplanting) and higher grain yield per infested plant at maturity. The grain yield per infested plant was significantly higher (P<0.05) in the tolerant variety (Cisadane) than in the control.