Evaluation of Specifi c Gravity of Potato Varieties in Ethiopia as a Criterion for Determining Processing Quality

Abstract

Specifi c gravity (SG) is the measure of choice for estimating dry matter (DMC) and starch content (SC) and ultimately for determining the processing quality of potato varieties. Evaluation of the SG of 25 potato varieties was carried out at three distinct locations in the Amhara region of Ethiopia with the main objectives of determining their culinary quality and most suitable areas of production. The varieties were planted in a 5 × 5 balanced lattice design of six replications during the 2011 rainy season. The results of the data analysis showed highly signifi cant (P < 0.01) genotypic and location differences and signifi cant (P < 0.05) genotype × environment interactions. The pooled SG values ranged from 1.058 to 1.102. The SG of tubers of the improved variety Belete was the highest while that of Menagesha was the lowest. Furthermore, the SG values for varieties grown at Debretabor were higher than those for the corresponding varieties grown at Adet and Merawi. The DMC and SC were computed based on the SG and showed signifi cant (P < 0.01) genotypic variability. The highest DMC and SC were also obtained at Debretabor; thus, it is an ideal location to grow potatoes for high DMC and starch accumulation. Additive main effects and multiplicative interaction analysis identifi ed CIP392640.524, Zengena, Jalenie and Belete as stable genotypes with SG values above average.