Effects of first irrigation date and organic fertilizer treatments on Saffron (Crocus sativus L.) yield under Khaf climatic conditions

In order to investigate the effects of first irrigation date and organic fertilizers on growth and yield characteristics of saffron، an experiment was conducted as a split-plot based on a randomized complete-block design with three replications، in Khaf city during growing season 2013-2014. Date of first irrigation treatment in three levels (15 September، 30 October and 15 November) was allocated as main plots and fertilizer treatment in five levels (control، humic acid at 5 and 40 liters per hectare، cow manure at 5 and 40 t. ha-1) was set as subplots. Analysis of variance showed that the date of first irrigation had a significant effect on all studied traits except for total fresh weight of corm and the average weight of corm of saffron. Effects of different organic fertilizer treatments on all studied traits were significant، except for corm number with 8 g (8. 00) weight were obtained in first irrigation on 6th November. The first irrigation at 7th October was superior to the other irrigation treatments for corm number with