| dc.description.abstract | The present study was conducted during two consecutive winter seasons of 2012-2013 and 2013- 2014 at
the experimental field and Laboratory of Horticulture Department at Sylhet Agricultural university with a
view to characterize seven exotic sweet potato genotypes, to observe the effect of harvesting stages and
effect of planting dates on growth and yield of sweet potato under AEZ Sylhet condition. The seven sweet
potato genotypes viz., SP001, SP002, SP003, SP004, SP005, SP006 & SP007 were evaluated under RCB
(Factorial) design to estimate growth and storage root yield at 120 day and 150 day after planting. In
addition chemical analysis of storage root of seven genotypes harvested at 120 day were done to estimate
nutrient content. In the winter season of 2013 the three selected genotypes of SP004, SP006 and SP007
were evaluated at three different planting dates under RCB (Factorial) design to observe growth and yield
of sweet potato. Variation in physical-morphological characteristics like colour of vine, leaf vein, petiole,
root, flesh was observed among the genotypes. Length of the root was varied from 7.34 cm (SP002) to
12.18 cm (SP004). The highest root width was recorded from the genotype SP004 (6.68 cm) while it was
the lowest for SP002 (3.35 cm). Most of the genotypes produced storage root had red purple in colour
while SP004 was white in colour. Flesh colour of the root was mostly creamy white except SP006 which
had flesh with orange in colour. Among the seven sweet potato genotypes, SP004 produced the highest
root yield per plant (310.83 g) and corresponding root yield per hectare (17.2 t) followed by SP007 (14.7
t/ha) and SP006 (12.77 t/ha). All the genotypes performed better in relation to root yield at 150 day after
planting compared to 120 day after planting. Average root yield per plant (230.90 g) and per hectare (12.77
ton) of the genotypes at 150 day after planting was much higher than the yield when the plants harvested at
120 day after planting (9.0 t/ha). Chemical analysis of the storage root revealed that the genotype SP007
was comparatively better source of Ca, Mg, Fe and Zn whiles the genotype SP001 rich in potassium and
phosphorus and copper. The genotype SP004 also a rich source of the elements of Ca (1.39%), Mg (0.40 %), K (1.83 %) and Zn (10.08 ppm). Dry matter content in the storage root ranged from 25 % to
32 % among the seven genotypes at 120 day after planting while it was ranged from 26-33 % at 150 day
after planting. The highest root yield was recorded from the plants grown from 1 November planting (20.5
t/ha) closely followed by the plants of 1 October planting (20.13 t/ha). However, the genotype SP007
produced the highest root yield (22.5 t/ha) when grown from 1 November planting followed by the same
genotype in 1 October planting (21.9 t/ha) and SP006 (21.9 t/ha) at 1 November planting. The highest dry
matter content in the root was estimated from the plants grown from 1 September planting (32.3 %) closely
followed by 1 November (31.9 %) and 1 October planting (29.7 %). | en_US |
