Abstract:
Potato (Solanum tuberosum L.) is an important leading tuber crop for food and nutrition
security as well as cash crop for smallholder farmers in Ethiopia. However, the yield of the
crop is low at national as well as regional level which is constrained mainly by in appropriate
planting density and low soil fertility. There is a need to optimize planting density and
fertilizer to enhance crop growth and tuber yield. Therefore, a field experiment was
conducted to investigate the effect of planting density and NPS fertilizer on growth, yield and
yield components of potato at Jimma, south- western Ethiopia during the rainy season of
2019/2020. Four levels of intra-row spacing (20, 25, 30 and 35 cm) and four levels of NPS
fertilizer (0, 75, 150 and 225kg ha-1 NPS) were arranged in a randomized complete block
design with 3 replicates as a 4 x 4 factorial combination. Results of the experiment indicated
that the main effects of intra-row spacing and NPS fertilizer as well as the interaction effects
highly significantly affected days to 50% flowering, plant height, main stem number, days to
75% physiological maturity, total tuber number per hill, weight of tubers, marketable tuber
number per hill, unmarketable tuber number per hill, total tuber yield (t ha-1), marketable
tuber yield (t ha-1) and unmarketable tuber yield (t ha-1).Total tuber yield increased with the
increased plant population and NPS fertilizer. The highest total tuber yield (40.36 ton ha-1)
was obtained from the treatment combination of 20 cm intra-row spacing and 225kg ha-1
NPS. On the other hand, the lowest total tuber yield (13.4 tons ha-1) was recorded for the
treatment combination of 35cm intra-row spacing and zero NPS fertilizer application. Based
on the partial budget analysis, the treatment combination of 30 intra-row spacing and 225kg
ha+ NPS fertilizer gave the maximum net return of Birr 404255.3 ha-1.
