Effect of potasssium fertilizer on growth, quality, yield and profitability of papaya (Carica papayaL.) cv. Red Lady

Abstract

Field experiments were conducted to investigate the effect of potassium fertilizer on quality and production of papaya (Carica papaya L.) cv. Red lady-786 at four adjoining fields of farmers during two successive years from June, 2011 to July, 2013 in Sirohi (Rajasthan). The investigation comprised of seven treatments viz., 20 kg FYM + 300 g N + 300 g P, 20 kg compost + 300 g N + 300 g P, 10 kg vermicompost + 300 g N + 300 g P, 20 kg FYM + 300 g N + 300 g P + 300 g K, 20 kg compost + 300 g N + 300 g P + 300 g K, 10 kg vermicompost + 300 g N + 300 g P + 300 g K and absolute control. The incorporation of potassium fertilizer along with organic manures in papaya plants resulted in significant difference in yield and quality parameters compared to organic manures alone and absolute control but non-significant difference was observed on vegetative parameters. The application of 10 kg vermicompost + 300 g N + 300 g P + 300 g K plant−1year−1 resulted in maximum plant height (269.90 cm), stem girth (48.50 cm), number of leaves (48.30), leaf area (9.54 meter2), fruit weight (2.19 kg fruit−1) and yield plants−1 (92.28 kg) but statistically at par with FYM and compost along with 300 g N + 300 g P + 300g K plant−1year−1. Similarly, maximum per cent fruit set (46.45), yield ha−1 (2303 qt ha−1) and best quality parameters such as high TSS (13.5°Brix), and longer keeping quality (7.62 days) were recorded with the potassium when added with organic manures. The highest net return (9.50 lakh ha−1) and benefit: cost ratio (4.68) was also found with 10 kg vermicompost + 300 g N + 300 g P + 300 g K plant−1year−1, which indicate the overall suitability of potassium fertilizer in papaya crops. The incorporation of potassium fertilizer increased the resistance of plant also with delayed appearance of leaf curl virus and less number of infected papaya plants.