Evaluation of Physiological Cost and Subjective Assessment of Power Paddy Weeder for Wet Land Paddy

Mechanical weeders are performing activities such as weeding and hoeing simultaneously and thus reduces the time, cost and drudgery involved in manual weeding. The physiological response of the subject was assessed while operating a power paddy weeder for weeding paddy in wet land cultivation. The cardiac cost involved in the operation of power paddy weeder was found out and the mean working heart rate value of the subject was 108 beats min-1. The energy expended during operation of a power paddy weeder was 19.50 kJ min-1. The oxygen uptake in terms of VO2 max was 46 % which was above the acceptable limit of 35 % of VO2 max. The weeding efficiency was found to be 85 %. Area covered by the power paddy weeder was 25 cent/hour ( (row to row spacing is 23.8 cm while using self propelled rice transplanter) and area covered by the power paddy weeder was 30 cent/hour while planting 30 cm row spacing. The machine requires 0.5 litre petrol to cove 1 hr. Mean overall discomfort rating on a 10 point visual analogue discomfort scale ( 0- no discomfort, 10- extreme discomfort) was 3.0 and scaled as light discomfort. More tillers have been produced after using this equipment and soil aeration and root growth was improved. It is comfortable to operate this machine. If only one worker is engaged for the weeding operation with this equipment, 7 min rest could be provided after operating the equipment continuously for the 30 min period.