effects of planting date and corm density on growth and yield of saffron (crocus sativus l.) under malayer climatic conditions

in order to evaluate the effects of planting date and corm density on yield and some other traits of saffron under climatic conditions of malayer in the west of iran, an experiment was conducted using split plots based on randomized complete blocks design with four replications. different planting dates (15th july, 15th august and 15th september) were allocated in the main plots and different corm densities (25, 50, 75 and 100 corms.m-2) were in the subplots. based on results, the effects of planting date on flower number, leaf number, length and weight of stigma was significant, whereas effects of planting density on flower number and flowering period, leaf length and number, stigma length and weight, number of daughter corms and stigma yield was significant. the highest amount of saffron yield (2.7 kg.ha-1) obtained in the first planting date but there wasn’t significant different between planting date treatments. none of experimental treatments have significant effects on the beginning of flowering, but by increasing corm density the length of flowering period significantly decreased. by increasing planting density from 25 corms.m-2 to 100 corm.m-2 the number of daughter corms decreased by 56%. generally, planting date of 15th of july caused higher growth in saffron than other planting dates. a number of 100 corms.m-2 showed higher yield and shorter length of flowering period.