Ergonomic Assessment of Walk-behind Battery-powered Two-wheel Weeder

Various types of manual weeders are developed for mechanical weeding in line sown crops to reduce the potential losses in the crop production system. Forces required for an operation of weeder is up to 384 N. An ergonomic study was conducted on a walk-behind type battery-powered two-wheel weeder for physiological aspects, discomfort, rapid entire body assessment (REBA) and postural parameters to assess discomfort/ drudgery on operator. The battery-powered weeder was studied with two attachments: three-tine shovel type and sweep type cultivators. The average heart rate of subjects was recorded at 120 and 114 beats.min^-1 with shovel type and sweep type cultivators, respectively. It was found that energy expenditure of subjects reduced by 28.5% to 37.5% in battery-powered two-wheel weeder as compared to manual weeder. The average body parts discomfort score (BPDS) was 26.54 with shovel type cultivator and 23.35 with a sweep type cultivator. The average twisting velocity, sagittal flexion and maximum lateral velocity of subjects during operation of battery-powered weeder with sweep type and shovel type cultivators were 4.33 to 4.55 degrees s^-1, 24.47 to 24.97 degrees and 65.55 to 67.63 degrees s^-1. The REBA score indicates need for possible modification in design of handle as per anthropometric dimensions in existing battery powered unit/weeder. The field capacity of the battery-powered two-wheel weeder was 0.0515 and 0.0434 ha h^-1 with a shovel type cultivator and sweep type cultivator, respectively.