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.