Efficacy of novel insecticide molecules against stem borer complex in paddy

Abstract:

Nearly 18% of annual paddy losses across sub-Saharan Africa are attributed to stem borer attack, yet field data on newer chemistries remain limited for southern African rice ecologies. This research evaluated six insecticide molecules against the stem borer complex in transplanted paddy during Kharif 2023 at Limpopo Agricultural University, Polokwane, South Africa. A randomized block design with seven treatments and three replications was used. Chlorantraniliprole 0.4% GR recorded the highest larval mortality (89.4% at 14 DAT) and lowest white ear incidence (3.7%), followed by flubendiamide 39.35% SC (85.6% mortality, 5.2% white ears). Fipronil 0.3% GR and thiamethoxam 25% WG showed intermediate efficacy. Grain yield was highest under chlorantraniliprole (5.83 t/ha), representing a 41.6% gain over the untreated control (4.12 t/ha). These results position chlorantraniliprole and flubendiamide as effective alternatives for stem borer management in southern African paddy systems.