STANDARDIZATION OF AGRO-TECHNIQUES FOR THE PRODUCTION OF PROCESSING QUALITY POTATO

Abstract

Six experiments were carried out at the Tuber Crops Research Center of Bangladesh Agricultural Research Institute, Gazipur during the period from November 2012 t0 February 2015 with a view to developing a package of agro-techniques for maximizing process grade tuber yield and quality. The popular potato variety BARJ Alu 28 (Lady Rosetta) was used in all the experiments. ln the first experiment, planting time and dehaulming schedule were evaluated to maximize process grade tuber yield and quality. Response of different planting geometry was measured in the second experiment. In the third experiment seed tuber size and inter row spacing were standardized. Nitrogen and potassium fertilizers were evaluated to find out the optimum doses for higher process grade yield and quality in the fourth experiment. ln the 5th experiment, the treatments found most effective in experiments 2, 3 and 4 were accumulated and compared in different combinations to formulate the best agro-technique package, In the 6th experiment, the treatments found most effective in previous two experiments of nitrogen and potassium were evaluated with cowdung manure for better quality processing tubers production. Results indicated that significantly higher yield of process grade tuber was recorded in November I5 planting in combination with all the dehaulming schedules, ranged from 20.67 to 21.50 t/ha. Processing quality parameters like high specific gravity and dry matter and low reducing sugar content were significantly influenced in the former planting time under dehaulming at 90 days after planting. The chips and French fry grade tubers as well as total tuber yield were the highest at 67.5 cm x 25 cm spacing. Medium sized seed tuber found profitable for maximizing tuber yield as well as dry matter production under 25 cm intra row spacing. This combination also gave the highest yield of chips grade tuber (21.9 t/ha). Nitrogen and potassium in combination significantly increased the chips and French fry grade tuber number and weight per hill as well as their yield. Reducing sugar content was the lowest (31.97 mg/I 00 g fresh weight) at 200 kg K/ha. Dry matter content increased up to 150 kg/ha of both N and K doses and higher doses showed declining tendency. With cowdung manure, an integrated plant nutrient supply method increased yield and quality of process grade tubers. However, the quality of process products vary significantly with all other factors except planting geometry, seed size and organic matter.