Comparison of Methods for Dry Matter Content Determination in Potato Using Multi-Environments Field Data and Stability Statistics

Abstract

Tuber dry matter content (TDM) is considered as the main determinant of processed potato tuber quality. In order to investigate rapid, practicable and reliable methods for the measurement of TDM, a study was planned to compare three standard methods (digital potato hydrometer, moisture-drying on quartz seasand and oven-dry) among 189 diverse potato genotypes, grown under three environmental conditions (Hatay "standard water application", Konya "standard water application" and Konya "drought" conditions). ANOVA revealed highly significant differences (p<0.01) in all treatments among tests, checks and tests vs check genotypes. Environmental conditions significantly affect the TDM, while methods showed differential response within the tested environments. A strong correlation (r) and high goodness of fit (R 2 ) was observed between seasand and hydrometer methods as compared to oven-dry method. Wide applicability and reliability of seasand and hydrometer methods were also confirmed by stability statistics. This study recommends seasand as an accurate and hydrometers as rapid method in contrast to oven dry method for the measurement of TDM. Parametric stability methods such as bi and S 2 di identified stable genotypes with optimum TDM, that can serve as a useful resource for breeding of processing cultivars.