Evaluation of planting date effects on yield and yield components of Savalan and Agria cultivars in Ardabil region

This experiment was conducted for determination of most suitable planting dates for cultivation of potato mini-tubers of Savalan and Agria cultivars in Ardabil Agriculture and Natural Resources Research Station during 2007-2008. Experimental design was split plot on the basis of randomized complete blocks with two factors in three replications that main plots had four planting dates (April 20, May 4, May 21 and June 4) and the subplots had two cultivars (Savalan and Agria). Plant height, main stem number per plant, total and marketable tuber yield, total and marketable tuber number and weight per plant were measured during growth period. Analysis of complete variance showed that there were significant differences between years on marketable tuber yield, total tuber number per plant and marketable tuber weight per plant, between planting dates on total and marketable tuber yield, between cultivars on total and marketable tuber yield, plant height, total and marketable tuber number and weight per plant, between years and cultivars on marketable tuber yield, plant height, main stem number per plant and marketable tuber weight per plant and between year, planting date and cultivars on marketable tuber yield, plant height, main stem number per plant, total and marketable tuber weight per plant. The maximum total and marketable tuber yield and marketable tuber number per plant belonged to May 4 and May 21 planting dates. Savalan cultivar had higher total and marketable tuber yield, plant height, total and marketable tuber number and weight per plant toward Agria cultivar.