Abstract

Potato (Solanum tuberosum L.) is an important food and cash crop in Ethiopia; serving, as a food security crop due to its nutrition content, wider adaptability and early maturing behavior. However, the yield of the crop is constrained by a number of factors. Among which unspecified seed tuber size and limited availability and distribution of improved varieties are among the important limiting factors. A field experiment was conducted to study the effects of seed tuber size on growth and yield performance of potato varieties at Agarfa, Agricultural Technical and Vocational Education and Training College experimental field during 2017. The treatments consisted of three potato varieties (Gudenie, Jalene and Kellacho) and three seed tuber sizes (25-34, 35-45 and 46-55 mm). The experiment was laid out in a randomized complete block design with a factorial arrangement and replicated three times. The results showed that, seed tuber size and varieties significantly affected phenological parameters, stem number, leaf area index, stem density, marketable, unmarketable and total tuber yield, shoot fresh and dry weight, underground fresh weight, and medium weight of tuber size. Leaf number, and underground dry weight and tuber size were significantly affected only by seed tuber size. Varieties and seed tuber size interact to influence plant height, leaf area, number of tuber per plant, dry matter concentration and harvest index. Gudenie and Jalene produced the highest total tuber and marketable yields. Large seed tuber size (46-55 mm) produced higher marketable tuber yields than medium and small tuber sizes. In conclusion, Gudenie variety and large seed tuber size showed superior performance both for tuber yield and tuber dry matter concentration compared with the remaining varieties and small tuber size. Therefore, farmers are encouraged to produce Gudenie or Jalene variety with the use of medium to large seed tuber size for potato production.

Key words: Agarfa, Gudenie, Jalene, potato, seed tuber size and tuber yield.