Effect of Organic Sources of Nutrients on Tuber Bulking Rate,Grades and Specific Gravity of Potato Tubers

A field experiment was conducted during 2008–2009 and 2009–2010 to investigate the effect of organic sources of nutrients on tuber bulking rate, grades and specific gravity of potato tubers. The experiment consisted 24 treatment combinations with 8 treatment in popcorn control, recommended dose of fertilizers (N₁₂₀P₂₅K₃₅ kg ha^?1), farmyard manure equivalent to 120 kg N ha^?1, leaf compost equivalent to 120 kg N ha^?1, vermicompost equivalent to 120 kg N ha^?1, farmyard manure equivalent to 90 kg N ha^?1, leaf compost equivalent to 90 kg N ha^?1 vermicompost equivalent to 90 kg N ha^?1 in succeeding crop of potato, three treatments control, farmyard manure equivalent to 60 kg N ha^?1 and farmyard manure equivalent to 90 kg N ha^?1] were superimposed on the different treatments of pop corn. It was found that the application of farmyard manure equivalent to120 kg N ha^?1 to pop corn and farmyard manure equivalent in 90 kg N ha^?1 in potato gave the highest values of tuber bulking rate, specific gravity, number of large–sized (A–grade) and medium–sized tubers (B–grade) and total tuber yield followed by vermicompost equivalent to to 120 kg N ha^?1. Farmyard manure equivalent to 90 kg N ha^?1 to potato also recorded the higher bulking rate, tuber yield, specific gravity and a number of large sized tubers (A– grade and B–grade) as compared to the farmyard manure equivalent to 60 kg N ha^?1. The available N, P, and K in soil also improved with the application of organic manures.