| Summary: | Abstract Rice, (Oryza sativa L.), is liable to infestation with several insect pests, from which is the rice stem borer, Chilo agamemnon Bles. (Lepidoptera: Crambidae). Field trials were conducted in Egypt during 2015 and 2016 rice seasons to evaluate the efficacy of releasing the egg parasitoid, Trichogramma evanescens Westwood and applying different silica materials to reduce the pest infestation. The most efficient borer control was achieved when the parasitoid was released twice (each at 30,000 wasps/feddan) at Sakha, Gemmiza, and Sirw Agricultural Research Stations in 2015 season, at the maximum tillering stage plus at panicle initiation, as the borer infestation was reduced by (84.77%). Similar results (79.32% borer control) were obtained when the parasitoid was released at panicle initiation and heading rice plant growth stages. The parasitoid release was as efficient as the application of the widely applied insecticide (carbofuran). A large-scale release (17–20 feddans) was performed at the same research stations in the 2016 season. The parasitoid was released twice (each at 30,000 parasitoids/feddan) at the maximum tillering stage, 30 days after transplanting (DAT) and at panicle initiation (45 DAT). Dead hearts (DH) averaged (1.80 and 3.67%) in release and non-release treatments, respectively, with a reduction in DH of (50.95%). The corresponding reduction in white heads averaged (70.64%). Potassium silicate (68% Si, 500 kg/feddan), as basal after last tillage or magnesium silicate (62% Si, 2 kg /feddan), as a spray 20 and 40 days after transplanting achieved (58.25 and 45.31%) white head reduction, respectively, due to borer infestation.
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