Growth, bulb yield and quality of onion (Allium cepa L.) as influenced by nitrogen and phosphorus fertilization on vertisol. II: Bulb quality and storability

1 ) were arranged in a randomized complete block design, replicated three times. Regardless of the rate, N fertilization decreased bulb dry matter content by about 4% over the control. Pungency measured as pyruvate concentration improved with increase in the rate of N application and reached the highest value of 2.72 μmol ml -1 at a rate of 138 kg N ha -1 . Bulb storability study for eight weeks at ambient condition indicated that the highest level of N or P fertilizer caused the highest cumulative weight loss. It was also observed that bulb sprouting percentage of 63 and 53% were recorded from treatments that received 69 and 40 kg P ha -1 , respectively. Nitrogen at the rate of 115 or 138 kg ha -1 resulted in about 2.9% rotting of the bulbs. N fertilization improved pungency, reduced bulb dry matter content and storability by enhancing sprouting and rotting percentage. Bulb dry matter content, pungency and rotting percentage were not significantly affected by P fertilization and the lack of response may be due to the availability of adequate amount of P (16.02 ppm) in the soil.