Development of a tractor operated planter for direct sowing of onion crop

Onion (Allium cepa L.) is one of the major vegetable crop grown throughout India. A six row tractor operated planter for direct sowing of onion was developed using inclined plate seed metering mechanism. Experiments were conducted for seed metering unit in the laboratory. Inclined plates having 18, 24 and 30 grooves were evaluated in the laboratory. Performance was evaluated on the basis of missing index, multiple index and quality of feed index. Missing index was highest in case of 18 groove plate at speed of 2 km/h. It decreased with the decrease in forward speed and also with the increase in the number of grooves of the metering plate. Minimum missing index was for 30 groove plate at the speed of 1 km/h. Multiple index was highest at speed of 2 km/h for 30 groove plate. Minimum value of multiple index was 13.67 % at speed of 2 km/h for 18 groove plate. As the forward speed was increased from 1km/h up to 2 km/h, multiple index was decreased. Quality of feed index was best for 30 groove plate at the forward speed of 1.5 km/h. Based on the results of the laboratory evaluation, 30 groove seed metering plate and a forward speed of 1.5 km/h was selected for the field evaluation. Average field capacity of the machine was found to be 0.11 ha/h and average fuel consumption of the tractor was 3.2 l/h. The average germination count after 28 days of planting was found to be 14.66 plants/m row length. The average onion bulb size was found to be 4.94 cm, average bulb weight was 56.68 gm and the average yield of onion bulbs was found to be 133.6 q/ac which was comparable with that of transplanted onion