Response of Onion (Allium cepa L.) to Potassium Levels, Sources and Time of Application

The present investigation on “Effect of potassium levels, sources and time of application on growth and growth parameters of onion var. Arka Kalyan” was carried out at the College of Horticulture, Bagalkot, Karnataka during Kharif season of 2015 and 2016. Potassium significantly influenced the growth components like plant height, number of leaves per plant, leaf length, leaf breadth, neck thickness and biomass per plant with increasing levels of potassium at 30, 60 and 90 days after transplanting. Application of 200 per cent RDK recorded significantly higher plant height (37.08, 54.00 and 56.69 cm, respectively), number of leaves per plant (5.59, 8.66 and 9.88, respectively), leaf length (33.85, 47.50 and 48.02 cm, respectively), leaf breadth (5.19, 7.44 and 7.84 mm, respectively), leaf area per plant (154.52, 490.92 and 582.72 cm2, respectively), neck thickness (7.60, 13.90 and 15.08 mm, respectively) and biomass per plant (4.60, 8.22 and 14.70 g, respectively) and it proved significantly superior over 100 per cent RDK. Growth parameters like plant height, number of leaves per plant, leaf length, leaf breadth, leaf area per plant, neck thickness and biomass per plant varied significantly by potassium supplied as sulphate of potash over muriate of potash. The growth parameters was significantly influenced by the time of application of potassium. At 30 DAT, the application of 100 per cent potassium at transplanting was recorded significantly higher growth parameters compared to 50 per cent potassium at transplanting and 50 per cent K at 30 DAT was applied as basal. At 60 and 90 DAT, application of 50 per cent potassium at transplanting and 50 per cent K at 30 DAT was recorded superior growth over 100 per cent potassium at transplanting