Quality of Potato (Solanum tuberosum L.) Tubers as Influenced by Cultivar and Plant Spacing in Eastern Ethiopia

Abstract

A field experiment was conducted at Haramaya and Hirna during the main cropping season of 2013 to determine the appropriate plant spacing for potato cultivars in relation to tuber quality. The treatments consisted of five seed tuber spacing between ridges and seed tubers (75 cm x 30 cm, 60 cm x 30 cm, 60 cm x 25 cm, 50 cm x 25 cm and 45 cm x 20 cm) and four potato varieties (Bubu, Badhassa, Zemen and Chiro). The experiment was laid out as a randomised complete block design with three replications. The analyzed data results showed that the main effect of variety significantly (P < 0.01) affected almost all quality parameters of the crop and some of them responded significantly for the main effect of spacing. However, variety and plant spacing did not interacted to significantly influence most quality parameters at both locations except for specific gravity and total starch content. Mean result of the two locations indicated that Bubu had significantly higher specific gravity (1.106). In addition to variety, the highest specific gravity was recorded at the spacing of 75 cm x 30 cm (1.088), 60 cm x 30 cm (1.088) and 60 cm x 25 cm (1.086). At Hramaya, a significantly higher tuber dry matter content was recorded for Bubu (28.41%). At Hirna, Bubu, Badhasa and Chiro varieties had the highest tuber dry matter contents of 31.44%, 29.39% and 27.63%, respectively. Mean result of the locations showed that Bubu had higher total starch content (18.94 g/100g) than the other varieties. In terms of spacing, the highest total starch contents were recorded for spacing of 60 cm x 30 cm (15.44 g/100g), 75 cm x 30 cm (15.36 g/100g) and 60 cm x 25 cm (14.92 g/100g). Mean results of the two location showed that tubers of Chiro, Zemen and Bubu had higher pH (6.079, 6.036 and 6.01, respectively). At both locations, Bubu had the highest total soluble solids while Chiro and Zemen had the lowest.

Keywords: Inter and intra row spacing; Solanum tuberosum L.; cultivar, specific gravity; dry matter content; total starch content; pH