Effect of drip fertigation on growth and yield of onion

Abstract

Investigations were carried out in onion at the Department of Vegetable Crops, Horticultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore during 2007-2008 on fertigation in onion. The varieties used for experiment were Agri Found Dark Red (big onion) and COOn5 (aggregatum onion). The experiments were laid out in a RBD with four treatments in five replications. The performance of drip fertigation at 75%, 100% and 125% was compared with the soil application of recommended dose of fertilizer. The results indicated that in big onion var. Agri Found Dark Red, the fertigation with 75 per cent recommended dose of fertilizers (i.e., 75: 112.5: 56.25 kg of NPK ha-1) registered higher bulb yield (10.30 and 12.70 t ha-1). In small onion var. COOn5, the fertigation with 75 per cent recommended dose of fertilizers (i.e., 45: 45: 22.5 kg of NPK ha-1) registered higher bulb yield (8.34 and 11.05 t ha-1) compared to soil application of fertilizer. The nutrient uptake pattern also increased with application of 75 per cent recommended dose of fertilizer as fertigation. Based on the economic analysis, application of 75 per cent RDF a straight fertilizers viz., Urea, SSP and SOP through fertigation recorded the highest benefit cost ratio than the other treatments and it was adjudged to be the best nutrient management practice for both the onion varieties.