PRODUCTIVITY AND PROCESSING QUALITY OF POTATO AS INFLUENCED BY GROWTH DURATION, TIME OF NITROGEN APPLICATION AND INTRA-ROW SPACING

Abstract

The present experiment was carried out in the research field of Sher-e-Bangla Agricultural University (SAU), Dhaka-1207, during November, 2015 to March, 2016 to investigate the effects of growth duration, time of nitrogen application and intra-row spacing on the productivity and processing quality of potato. Variety “Asterix” was used as planting material under present study. The present experiment was comprised of three different factors as treatments namely, factor A: growth duration (G): G = Harvested at 90 days after planting (DAP) and G 2

1 = Harvested at 100 DAP; factor B: time of nitrogen application (T): T = 135 kg N ha -1 (at planting) + 135 kg N ha -1 (at first earthing up, 35 DAP), T 2 = 135 kg N ha (at planting) + 67.5 kg N ha -1 (at first earthing up, 35 DAP) + 67.5 kg N ha -1 (at second earthing up, 50 DAP), T 3 = 135 kg N ha -1 (at planting) + 67.5 kg N ha -1 (at first earthing up, 35 DAP) + 58.5 kg N ha -1 (at second earthing up, 50 DAP) + 9 kg N ha -1 as 1 foliar spray (2% urea) at 60 DAP and T 4 = 126 kg N ha -1 (at planting) + 126 kg N ha -1 (at first earthing up, 35 DAP) + 18 kg N ha -1 as 2 foliar spray (2% urea) where first 9 kg N ha -1 applied at

50 DAP and second 9 kg N ha -1 applied

at 60 DAP and factor C: intra-row spacing (S): S 1 = 60 cm X 20 cm and S = 60 cm X 25 cm. The experiment was laid out in a 3 factors split-split-plot design with three replications, where the growth duration assigned to main plots; time of nitrogen application to sub-plots and intra-row spacing to sub-sub-plots. Results demonstrated that most of the parameters studied under present experiment had significantly influenced by growth duration, time of nitrogen application and intra-row spacing. Result revealed that weight of tuber hill (g), average weight of tuber (g) and tuber yield (t ha -1 ) was found the highest (382.29 g, 55.87 g and 37.68 t ha -1 ) under G 1 T 3 S 2 i.e., 135 kg N ha -1 (at planting) + 67.5 kg N ha (at first earthing up, 35 DAP) + 58.5 kg N ha -1 (at second earthing up, 50 DAP) + 9 kg N ha as 1 foliar spray (2% urea) at 60 DAP, wider spacing (60 cm × 25 cm) in combination with earlier growth duration (at 90 DAP) is the best for improving the tuber yield of potato whereas G 2 T 1 S showed the lowest one. On the other hand, in case of quality traits such as specific gravity, dry matter (%) and starch content (mg g 1 -1 FW) of potato tuber G 1 T i.e., 126 kg N ha -1 (at planting) + 126 kg N ha -1 (at first earthing up, 35 DAP) + 18 kg N ha as 2 foliar spray (2% urea) where first 9 kg N ha -1 applied at

50 DAP and second 9 kg N ha at 60 DAP, wider spacing in combination with earlier growth duration (90 DAP) exhibited the better (1.11, 22.92 % and 24.01 mg) performance which was statistically similar to G i.e., 135 kg N ha -1 (at planting) + 67.5 kg N ha -1 1

(at second earthing up, 50 DAP) + 9 kg N ha 4 -1 S 2 -1 -1 applied (at first earthing up, 35 DAP) + 58.5 kg N ha -1 as 1 foliar spray (2% urea) at 60 DAP, wider spacing (60 cm × 25 cm) in combination with early growth duration (at 90 DAP). From this study, it may be concluded that from the standpoint of yield and quality considerations, an advantages of earlier growth duration, split applications of nitrogen as soil and foliar spray under wider intra-row spacing may put remarkable influence for improving the yield and processing quality of potato tuber for the betterment of farming community.