Ergonomic Evaluation of Cono Weeder for Wet Land Paddy

Weeding is one of the most important field operations & consumes 15 % of the total energy spent in crop production. The cardio respiratory performance of men operators was studied in cono weeder for weeding paddy in wet land cultivation. Psychophysical measurement technique was used to quantify the overall discomfort as well as body part discomfort. The average working heart rate of the subject was 121 beats min-1. The predicted oxygen consumption rate was 1.146 l min-1 that is 56 % of their aerobic capacity (VO2 max) which was above the acceptable limit of 35 % of VO2 max. The weeding index was found to be 75 %. Area covered by the cono weeder was 15 cent/hour ( (row to row spacing is 23.8 cm while using self propelled rice transplanter) and area covered by the cono weeder was 20 cent/hour while planting 30 cm row spacing. Mean overall discomfort rating on a 10 point visual analogue discomfort scale ( 0- no discomfort, 10- extreme discomfort) was 5.0 and scaled as Moderate discomfort. It is suggested that two operators may be engaged in shift for a day long work with the cono weeder. It is easy to maintain this machine and the price was low. Wheels can be adjustable depending on the row. However weeding efficiency was less in hard soil and working is difficult in hard surface.