Field performance evaluation of manual and motorized weeder and comparison to hand weeding in paddy field

Among different methods of weed controls in agricultural crops, mechanical control has a special place from the viewpoint of its effectiveness, feasibility and flexibility. This method is important especially in paddy fields where the presence of high soil moisture content cause a proper conditions for growing weeds and severe infestation with main crop. Therefore, the development of appropriate mechanized weeding control is a need for increasing productivity and reducing the production cost. In this research the performance of four types of mechanical rice weeders compared to hand weeding in the paddy field. The experiment was conducted in split-plot design with two factors; variety as a main plot in two levels (Hashemi and Hybrid) and weeding method as a sub-plot in five levels (1. One row cono weeder W1, 2. two rows cono weeder W2, rotary weeder W3, 4. Motorized weeder W4 and 5. Hand weeding W5) based in randomized complete block design (RCBD) with three replications in Rice Research Institute of Iran (RRII). The results revealed that the effect of variety and weeding method significantly (p0.01) affected on weeding efficiency, damaged plants and field capacity of the evaluated weeders. The highest weeding efficiency (84.33%) was obtained in W4 and Hybrid variety and the lowest value (73.20%) was measured in W1 and Hashemi variety. The maximum of damaged plant of 4.40% was registered in W2 and Hashemi variety and the minimum of 0.13% was obtained in W5 and Hybrid. The highest effective field capacity was measured to be 0.082 and 0.087 ha/hr in W4 and the corresponding lowest values of 0.0084 and 0.0088 were obtained in W5 for Hashemi and Hybrid varieties, respectively. The weeding cost of mechanical weeders was decreased by 15.70, 38.51, 22.32 and 48.70% , respectively compared to hand weeding (W5). The break-even points of the weeders were found to be 0.079, 0.083, 0.070 and 1.24 hayr-1 for W1, W2, W3 and W4, respectively. Among the tested weeders, W4 showed a proper field performance.