The Effect of Pre-emergence Herbicide and Method of Planting on Weed Population and Yield of iMungbean in Farmer Fields.

Abstract

Mungbean variety M7A was planted in the farmer field in Bangpae district of Rachaburi Province in a split-split plot experiment. Main plots consisted of two fertilizer treatments, with fertilizer mixture of 16-20-0 at the rate of 312.5 kg/ha, and without fertilizer. Methods of planting of broadcasting seeds, and drill planting mungbean in row using row specing of 50 cm. were two sub plots. The sub-sub plot consisted of treatments receiving and not receiving preemergence herbicide, inwhich alachlor at the rate of 2.15 kg(ai)/ha was applied as herbicide treatment immediately after seeds were planted. Mungbean was planted in May as the crop before rice in mungbean-rice cropping system pattern. Weed competition was serious when mungbean was planted in early rainny season. Application ol' pre-emergence herbicide reduced weed numbers significantly. The yield of rnungbcan planted by drilling was significantly higher than broadcasting. ~pplication of pre-emergence herbicide significantly increase mungbean yield. If weed could not be contr~lled, the application of fertilizer would reduce mungbean yield by enhanced weed competition.