Study effect of planting date on relationship between yield, components, phenological, morphological characteristics in winter wheat varieties in Ardabil Region

This study was conducted to evaluate different planting dates on grain yield and its components in six bread wheat cultivars (Mihan, Pishgham, Alvand, Kaskouzhn, Saysounz and Orom) and three planting dates 20 October, 4 November and 5 December based on split plot design in a randomized complete block design with three replications in Ardabil Agricultural and Natural Resources Research Station during 2015. Analysis of variance showed there was significant differences between different planting dates, cultivars and their interaction in terms of plant height, pedancle length, awn length, number of nodes, main spike length, number of spikelets per spike, weight of main spike, number of seed per plant, number of seed per spike, seed weight per plant, seed weight per spike, 1000 seed weight, the number of days to emergence, stem elongation, flag leaf emergence, heading, pollination, maturity, grain yield and protein percentage. The highest grain yield were observed in Kaskouzhn, Orom, Saysounz and Pishgham cultivars in first and second planting date and Alvand and Mihan cultivars in the first planting date. The Kaskouzhn, Orom, Saysounz and Pishgham cultivars had the highest harvest index in the first planting date. Grain yield, plant height, seed weight per plant, 1000 seed weight and lysine content in the first planting date was higher than the second and third planting dates. Average grain yield in first planting date was 8.74 ton per hectare, the second planting date 7.11 ton per hectare and third planting date was 5.30 ton per hectare. With delaying planting 3.44 ton per hectare (about 40%) decreased grain yield. The number of days to emergence, stem elongation, flag leaf emergence, heading, pollination and maturity was in third planting date higher than the first and second planting dates. Relationship between grain yield with harvest index, neck length, main spike length, number of fertile tillers, days to flag leaf emergence, days to heading, the number of days to pollination and days to maturity was positive and significant and between lysine negative and significant.