Herbicide evaluation for rice

Abstract

Two herbicide experiments on rice were conducted at the Gurabo and Lajas Substations in 1979 and 1980. Rice cultivar Brazos was planted in 3.1 x 3.1 m plots. Herbicides butachlor [N-(butoxymethyl)-2-chloro-2' ,6' -diethylacetanilide], oxadiazon [2 tert-butyl-4(2,4-dichloro-s-isopropoxyphenyl)-∆²-1,3,4 oxadiazolin- 5-one] and propanil (3,4-dichloro-propionanilide) alone or in combination were evaluated for weed control and grain yield. Butachlor at 3.36 and 6.72 kg ai/ha; oxadiazon at 1.12 and 2.24 kg ai/ha; and propanil at 3.36, 6.72 and 13.44 kg ai/ha; and their mixtures gave good to excellent weed control. As a group, propanil provided a better safety margin to rice than butachlor and oxadiazon. All propanil-treated plots outyielded those of the other herbicides.