EFFECT OF GROWTH DURATION, N APPLICATION AND ROW SPACING ON PRODUCTIVITY, PROFITABILITY and PROCESSING QUALITY OF POTATO

Abstract

A field trial was conducted at Modipuram (India) during 2005-2007 on potato cultivar Kufri Chipsona-1 with 110 and 120 days crop duration in main plot, while sub-plot consisted of combination of four time of N application (2 split, 3 split, 3 split + 1 foliar spray, and 2 split + 2 foliar spray) and two within-row spacings (67.5 √ 20 and 67.5 √ 25 cm). Prolonged growth, N application time and crop geometry did not influence emergence, shoot number, plant height, leaf number and leaf area index. Total as well as process grade tuber number, yield and process grade tuber weight also remained unaffected due to crop duration and time of N application. In contrast tuber number and productivity declined with wider spacing. Processing attributes like chip colour and reducing sugars were within acceptable range for all treatment combinations, although excess soil or foliar N application late in the season resulted in lowering the tuber specific gravity and dry matter. economic analysis indicated that application of 270 kg N/ha in two equal splits at planting and earthing-up gave 7.5% more returns over 3 splits + 1 foliar spray of urea. Crop duration of 110 days and wider spacing were optimum for harnessing the yield potential and realizing higher returns and benefit cost ratio.