Comparative studies on different mechanical weeding methods inkharif maize (Zea mays L.)

A field experiment was conducted for two years at Hill Agricultural Research and Extension Centre, Dhaulakuan during kharif seasons of 2007 and 2008 to determine the most suitable and economical combination of mechanical weeding sequence in maize crop. The single weeding operations such as CIAE wheel hoe, manual hand weeding with khurpa, halod and earthing up were found to be significantly better than no weeding. In case of double weeding operations, CIAE wheel hoe + halod (41.36 q/ ha) and manual hand weeding + halod (41.24 q/ha) gave significantly higher maize grain yields as compared to manual hand weeding+manual hand weeding (30.58 q/ha), manual hand weeding+earthing up (32.20 q/ ha) and halod+earthing up (30.80 q/ha). However, the weeding sequences of CIAE wheel hoe+halod+earthing up and manual hand weeding+halod+earthing up gave highest maize grain yield of 44.32 and 44.24 q/ha respectively. Since earthing up after halod contributed only 3.00 q/ha, to the yield, the additional cost of weeding operation was very high as compared to the additional yield. The weeding sequences of CIAE wheel hoe followed by halod and manual hand weeding followed by halod gave almost similar maize grain yields. However, the operational cost in case of weeding sequence of manual hand weeding followed by halod (Rs. 6400/ha) was significantly higher than the weeding sequence of CIAE wheel hoe followed by halod (Rs. 3400/ha). Also the net returns (Rs. 21500/ha) over the control for the weeding sequence of CIAE wheel hoe followed by halod were highest as compared to all other treatments. Therefore, primary weeding done through CIAE wheel hoe 15-20 days after sowing and secondary weeding done through halod 30-35 days after sowing was the most economic and efficient combination of weeding operation in kharif maize crop.