Abstract:
Plant spacing and seed tuber size are important agronomic management practices in the
production of potato (Solanum tuberosum L.). However, potato farmers in Ethiopia often use
haphazard plant spacing and tuber sizes, which contributes to the low yield of the crop. A field
experiment was conducted during off season of 2014 at the research field of Holetta Research
Centre, Ethiopia with the objective of elucidating the effect of varied seed tuber spacing and
seed tuber sizes on the productivity of the crop. The treatments consisted of five levels of plant
spacing (75 x 30 cm, 60 x 30 cm, 60 x 20 cm, 50 x 30 cm and 50 cm x 20cm)and four seed tuber
sizes (25-34, 35-45, 46-55 and >56mm) using potato variety named Belete. The experiment
was laid out as a randomized complete block design in a factorial arrangement and
replicated three times. The results indicated that seed tuber size and plant spacing
significantly (P< 0.05) influenced most of growth, yield, yield components and some tuber
quality parameters of the crop. Total tuber yield and marketable tuber yield t ha-1 significantly
(P< 0.05) affected by plant spacing and seed tuber size where the maximum marketable tuber
yield (33.68 t ha-1) and total tuber yields (34.38 t ha-1) were obtained in response to the
spacing of 60 x 30 cm and 50 x 20 cm, respectively, while highest total and marketable tuber
yields of 36.16 and 37.65 t ha-1, respectively, obtained large-sized tubers (>56 mm). The
widest plant spacing and the medium-size seed tubers (35-45mm) 17.06 and 16.28 t ha-1 was
produced higher yield of large tuber sizes, respectively. The closest plant spacing (50 x 20 cm)
and the largest-sized tubers (>56mm was produced highest yields of small and medium-sized
tubers, respectively. The maximum starch yield of 8.07 t ha-1was produced from large-sized
tubers (56mm) and the lowest yields of starch 5.45 t ha-1 was obtained from small-sized tubers
(25-34mm).The use of medium plant spacing (60 x 30 cm) and medium-sized tubers (35-
45mm) led to the production of the highest yield of the tested potato variety. In conclusion, the
study revealed that potato production could be maximized by manipulating either plant
spacing and/or seed tuber sizes to be planted.
