EFEITO DE HERBICIDA NA QUALIDADE FISIOLÓGICA DE SEMENTES EM ARROZ VERMELHO

Abstract

The sertão of the state of Paraíba concentrates the largest production of red rice (Oryza sativa) in Brazil, planted mainly by family farmers, using fairly rustic production systems. The objective of this work was to evaluate the influence of the herbicide use on the physiological quality of the seeds of the red rice crop. The herbicides 2,4-D and pendimethalin were used. The experiment was conducted under field conditions in the Departamento de Fitotecnia e Ciências Ambientais, do Centro de Ciências Agrárias (CCA), Campus II, da Universidade Federal da Paraíba (UFPB), located in the city of Areia - PB, which was divided into 4 blocks, spaced in 1 m, each containing 10 plots (10 treatments) of 4,0 mx 4,0 m. Fifty seeds per linear meter spaced at 0,.5 m were sown, cultivated under no-fertilization. The treatments were arranged in applications of different isolated and associated doses of the described herbicides and one control. The results were submitted to analysis of variance and the means were compared with the control by the Scott-Knott test (1974), at 5% probability. The results obtained for shoot length and root length were not significant, whereas the dry shoot and root dry mass variables presented significant differences at 5% and 1%, respectively. It was concluded that for the variables presented in this research there was no significant difference in the herbicides used, except for root dry mass, where the T9-Pendimethalin + 2,4D-3,19 L / ha mixture was used and the red rice tolerance to the herbicides Pendimethalin and 2,4D, since these did not affect most of the physiological characteristics of the seeds. Also, new studies are needed to increase knowledge about red rice cultivation with the variables studied in this study and on the influence of herbicides on the crop, which is still very rustic and little studied.