Evaluation of traditional, mechanical and chemical weed control methods in rice fields.

The effect of different weed control methods and efficiency of weeding in mechanized cultivation was evaluated on rice yield. The treatments consisted of (I) control treatment, where no weeding was accomplished (II) three hand weeding, (III) application of commercial herbicide (Butachlor ® , 2-Chloro-diethyl-N- acetanilide), (IV) application of mechanical weeding without engine power and (V) power mechanical weeding. Results showed that experimental treatments had significantly different effects (p=0.05) on yield traits and number of filled grains per panicle, while treatments had the significant effects on grain weight and dry weight of weeds in the first, second and third weeding methods at 1% of confidence level. Treatment (III) had its most significant effect on number of filled grains per panicle and yield performance standpoint, which was 3869.73 kg ha-1 in its highest peak. Treatment (IV) was ranked as second influential with 3705.97 kg ha -1 . In addition, under (II) and (V) treatments, 3559.8 kg ha -1 and 3444.94 kg ha -1 of yield produced, respectively. The minimum dry weight of weeds in all weeding methods was related to the treatment (III), (I) and (V), respectively. The correlation coefficient analysis showed that total yield had a significant positive correlation with the panicle grain yield per plant (r= 0.56*) and the number of grains per panicle -1 (r= 0.58*) and the number of filled grains (r= 0.62*). Total rice yield also had negative correlation of r = -0. 63* with weed dry weight at second weed sampling time (17 DAT). The weed dry weight at third and fourth sampling times (24 and 40 DAT) had negative correlations of -0.64** and r= -0.60* with rice yield, respectively.