Optimization of Operating Parameters of Vertical Axis Tool for Weed Control in Wetland Paddy Cultivation Using Box–Behnken Design Under Soil Bin Condition
摘要
Weeds are the major constraints to productivity in paddy cultivation, often leading to significant yield losses. Among various weed management approaches, mechanical weeding is preferred due to its operational efficiency and sustainability compared to manual and chemical methods. Traditional weeders commonly employ horizontal axis tools. In this study, a novel vertical axis rotary weeder was developed for wetland paddy fields. The weeder consists of a vertical shaft fitted with multiple blades arranged to perform weeding, with a tool spacing of 170 mm, aligned to the crop spacing used in the System of Rice Intensification (SRI). The vertical axis tool was mounted on the test rig powered by a 1.5 hp AC electric motor and the performance was evaluated under simulated conditions in a soil bin. The experimental design followed a Box–Behnken approach, with forward speed (1 km h−1, 1.5 km h−1, 2 km h−1), depth of operation (25 mm, 50 mm, 75 mm), and tool rotational speed (50 rpm [0.39 ms−1], 100 rpm [0.79 ms−1], and 150 rpm [1.18 ms−1]) as independent variables. The optimal parameter combination of 1.5 km h−1 forward speed, 50 mm depth, and 100 rpm (0.79 ms−1) tool rotational speed, resulted in the maximum weeding efficiency of 81.9% and minimum plant damage of 2.2%, both statistically significant (p < 0.05). Forward speed and depth of operation positively affected weeding efficiency, while higher tool rotational speed marginally reduced it. Under optimized operating conditions, the developed vertical axis weeder delivered improved weeding performance with minimal crop disturbance. The results demonstrated the effectiveness of the vertical axis weeder as a viable solution for efficient weed management in wetland paddy cultivation.