Abstract
Paddy is grown in almost all states of India and the state of Odisha contributes 4.0 million hectares to rice cultivation
practice. In India Rs. 4,200 million worth of crop is being lost every year due to weeds. There are many types of mechanical
weeders available for vegetable crops with wide working width. These are not suitable for line sown paddy field. There is no such
power weeder available which can work in both wet land and dry land condition. To eradicate these problems one power weeder
was developed. The power requirement of the weeder was first calculated and found to be 1.1 kW. Hence, the available petrol
engine of 1.33 kW with speed reduction of 34:1 was taken for fabrication of the weeder. Initially, three types of blade (L-type, Ctype,
hatchet type) were developed to see the efficacy of the blades. Each set of blade was fitted with the weeder and evaluated in
line sown paddy in dry land as well as in transplanted paddy in wet land by attaching a suitable float and compared with the
conventional weeding method. The highest weeding efficiency of hatched type blade was found to be 84.30% in wet land and
82.280 % in dry land, whereas the same for L-type blade and C type blade weeders were 72.83% and 62.79% in wet land and
71.03% and 63.67% in dry land at a soil moisture content of 14.5% respectively. The performance index of hatched shape, L
shape and C shape blade weeder were observed to be 186.49, 117.70 and 125.15 in wet land and 190.81, 148.16 and 126.47in dry
land at 14.5% moisture content respectively. At the same moisture content i.e.14.5%, the highest plant damage of 11.60% was
observed with L type blades while the lowest plant damage of 4.0% was observed with hatchet type blade. The increase in heart
rate (∆HR) of 20.667 bpm was achieved for L type blade while the lowest of 18.667 bpm achieved in hatchet type blade at the
same speed. It is concluded that the developed weeder with hatched type blade is most suitable for weeding in both wetland as
well as dry land line sown paddy field. The cost of operation of the developed weeder was found to be Rs 177.10/h and Rs
4997/ha
