Potato variety essential traits and their stability for organic starch production

In organic production of potatoes for processing into starch, it is essential to obtain high and stable starch yields, as determined by the yield of tubers and the content of starch in the tubers. The stability of these traits in potato varieties is especially important in variable environments affected by soil properties and climatic conditions. Pre-sprouting of the seed tubers before planting can accelerate plant development and promote acceptable starch yields in a shorter growing period. This study evaluated traits of seven potato varieties important for organic starch production, assessed trait stability in different environments and determined the effect of seed tuber pre-sprouting on plant development and stability parameters. Significant effects of genotype, growing environment, and their interactions on tuber yield, starch yield and starch content of the tubers were observed. No significant effects were found of seed tuber pre-sprouting on the performance of the tested traits. Four trait stability evaluation methods were applied to tuber yield, starch yield and starch content, including a modified Kang's yield-stability approach, and these showed inconsistent results. The modified Kang's stability rating could be further used for determination of the best performing varieties, with high values for the essential traits and relatively high stability for each individual trait.