Effects of Planting Dates on Yield and Yield Component of Mini-Tuber Potato Cultivars in Ardabil Region

In order to determine the most suitable planting date for maximum production of seed tuber yield in potato cultivars, this experiment performed with four potato cultivars (Agria, Marfona, Savalan and Ceaser) at four planting dates (April 9th, April 30th, May 20th and June 10th) by using split plot experiment based on randomized complete block design in three replications at Ardabil Agricultural and Natural Resources Research Station during 2009. During growth stage, the traits were like plant height, main stem number per plant, tuber number and weight per plant and total and marketable tuber yield were measured. Analysis of variance from measured traits showed that planting dates and cultivars in traits like plant height, main stem number per plant, tuber number and weight per plant and total and marketable tuber yield and interaction of between cultivar × planting date plant height, main stem number per plant and tuber number per plant were significantly different. The highest total and marketable tuber yield, tuber number and weight per plant, plant height and main stem number per plant were obtained from second planting date (April 30th) and the lowest from latest planting date (June 10th). The difference between total and marketable tuber yield in the second planting date (April 30th) as compared with the latest planting date (June 10th) was 13.35 ton ha-1. Savalan had the highest plant height, main stem number per plant, tuber number and weight per plant and total and marketable tuber yield. Relationship of total tuber yield with plant height, main stem number per plant, tuber number and weight per plant and marketable tuber yield were positive and significant.According to the results, planting date of April 30th was suitable for maximum production of tuber yield of cultivar Sabalan.