摘要：The field performance of four types of mechanical rice weeders including, single row conical weeder (W1), two rows conical weeder (W2), rotary weeder (W3) and power weeder (W4) was compared to hand weeding (W5). Two transplanted local and improved rice varieties namely Hashemi and Hybrid, respectively were selected for this study. The results revealed that among the mechanical weeders, the highest weeding efficiency (84.33%) was obtained with W4 and Hybrid variety and the lowest value (72.80%) was measured with W3 and Hashemi variety. The average of damaged plants in mechanical weeders was obtained as 3.83% compared to 0.13% in hand weeding. The highest effective field capacities of 0.082 and 0.087 hah-1 were measured with W4 and the corresponding lowest values of 0.0084 and 0.0088 hah-1were obtained with W5 for Hashemi and Hybrid varieties, respectively. The weeding cost was reduced by 15.70, 38.51, 22.32 and 48.70% for W1, W2, W3 and W4, respectively as compared to W5. The highest break-even point (1.24 hayr-1) was obtained with power weeder (W4). The average break-even point in weedres of W1, W2 and W3 was found to be 0.077 hayr-1. Among the tested weeders, W4 showed a proper field performance.
关键词：Paddy field; mechanical weeder; weeding efficiency; hand weeding
