Effect of herbicides on rice yield components

Abstract

Two brazilian rice cultivars IAC-165 and BR-IRGA 409 were seeded in pots and cultivated in a screenhouse under the climatic conditions of Goiânia, state of Goiás, Brazil. The herbicides bentazon, 2,4-D, propanil, butachlor, oxadiazon, thiobencarb and pendimethalin were applied to the plants on the recommended rates and dates to evaluate their effects on some rice yield components. The herbicides butachlor and oxadiazon only showed a trend to reduce production, without any significant difference from the control. On the other hand, 2,4-D was the most injurious of the herbicides to the rice production, reducing the number of panicles per plant and filled seed percentage of the cultivar BR-IRGA 409. The herbicides bentazon and propanil applied at post-emergence and thiobencarb applied at pre-emergence were the least phytotoxic products, not affecting any of the evaluated parameters.