Yield and quality of potato (Solanum tuberosum) tubers as influenced by nutrient sources under rainfed condition of Meghalaya

Abstract

Field experiment was conducted in three consquitive summer seasons of 2005 to 07 at Shillong, Meghalaya to study the effect of integrated nutrient management on productivity, storage and quality of potato ( Solanum tuberosum L.) under rainfed condition. The experiment was laid out in a split plot design with eight nutrient man- agement practices [organic manures, viz. farmyard manure (FYM), poultry manure (PM), vermicompost (VC) and their combinations with inorganic fertilizers] in the mainplots and seed treatment with three biofertilizers ( Azoto- bacter, PSB and Azotobacter + PSB) in the sub-plots. The results showed that the crop receiving 50% of the rec- ommended dose of NPK through inorganic fertilizers and remaining 50% recommended dose of N (RDN) through organic manures (FYM, PM or VC) or 100% recommended dose of NPK (120 kg N, 120 kg P O and 60 kg K O/ 2 5 2 ha) through inorganic fertilizers alone favorably influenced yield of different grades tubers and total tuber yield. Seed treatment with combination of Azotobacter and phosphorus solubilising bacteria proved better in enhancing the tuber yield, as compared to sole treatment of either Azotobacter or PSB. Three years pooled yield revealed that integrated application of 50% recommended dose of NPK through inorganic sources and 50% RDN through PM recorded highest tuber yield (22.73 t/ha), closely followed by 100% NPK through inorganic fertilizers (22.20 t/ ha), which were 228% and 223% higher over the control respectively. Maximum dry matter content (20.29%) and specific gravity (1.084) were found in treatment with 100% RDN through organic manures. Protein content was found 10.18% in the combination of 50% RDN through FYM and 50% recommended dose of NPK through inor- ganic fertilizers. Use of biofertilizers for seed treatment did not cause much variation in dry matter content, specific gravity and protein content. Physiological loss in weight, decay loss, total weight loss were recorded maximum with 100% recommended dose of NPK and minimum in the combination of 50% RDN through VC and 50% recom- mended dose of NPK through inorganic fertilizers.