Evaluation of year and cultivar on Mini-tuber production of potato (Solanum tuberosum l.) under destructive and non-destructive harvesting methods at greenhouse Conditions

This experiment, including healthy seedling of three advanced potato cultivars, was performed with four harvesting methods in the Vilkij biotechnology company laboratory and greenhouse in 2008 and 2009 in Ardabil. Experiment was factorial based on completely randomized design with three replications. One factor consists of four harvesting Scheduling [40 and 80 days after planting, 60 and 80 days after planting, 40, 60 and 80 days after planting and 80 days after planting (as control)]. Other factor consists of three potato cultivars (Agria, Savalan and Marfona). The following characteristics were measured: plant height, main stem number, mini-tubers number and weight per plant and per meter square, mini-tuber average size, mini-tuber number and weight smaller than 1 g, between 1-5 g and bigger than 5 g. Analysis of variance showed significant differences between years, harvesting methods and cultivars and their interactions for all of the traits studied. Only, between cultivars the number of tuber less than 1g was not significant. Savalan cultivar had the highest mini-tuber number and weight per plant and per m2, and mini-tuber weight less than 1 g in 40, 60 and 80 harvesting days, mini-tuber number less than 1 g in 40 and 80 harvesting days, and mini-tuber number and weight bigger than 5 g in 60 and 80 harvesting days. Mini-tuber number per plant had a positive and significant correlation with mini-tuber weight per plant, number and weight of mini-tuber per m2, mini-tuber number and weight between 1-5 g and less than 1 g. Cultivars were grouped according to all of traits in two clusters, Agria and Marfona in One cluster and Savalan in other cluster and according to different harvesting methods in three cluster 40, 80 days and 60, 80 days harvesting in one cluster, 40, 60, 80 days harvesting in second cluster and 80 days harvesting in other cluster. Savalan cultivar was selected based on environment variance, environment variation coefficient, Finlay and Wilkinson, Eberhart and Russell, within environment variation coefficient procedures as stable cultivar.