In order to study the effects of irrigation intervals and intecropped marjoram (Origanum majorana L.) (as a shading plant for reducing the possible effects of soil warming due to climate change) on the growth and yield of saffron (Crocus sativus L.), a field experiment was conducted as split-plot based on randomized complete block design with three replications at the Agricultural Research Station of Ferdowsi University of Mashhad, Iran during two growing seasons of 2007-2008 and 2008-2009. Three irrigation intervals (every 7, 14, and 21 days) and three planting combinations (1:1 (one row of saffron+ one row of marjoram), 2:1 (two rows of saffron+ one row of marjoram), 3:1 (three rows of saffron+ one row of marjoram)) and 1:0 (pure stand of saffron)) were allocated to the main and sub plots, respectively. Results indicated that the simple effects of irrigation interval and planting combination on the flower number, flower weight and stigma yield were significant. Also, the interaction effects between irrigation interval and planting combination on the flower number, flower weight and stigma yield were significant. The highest and the lowest of saffron stigma yield were observed in the irrigation intervals with every 14 (0.27 gm-2) and 7 days (0.09 gm-2), respectively. Also, the maximum stigma yield was observed in 1:1 (0.20 gm-2) and the lowest was for pure stand of saffron (0.15 gm-2. By increasing irrigation intervals from every 21 to 7 days enhanced the saffron growth characteristics and stigma yield. It seems that the intercropped saffron with marjoram increased the flower number and stigma yield of saffron due to decreasing soil temperature which could be regarded as an alternative to the possible effect of soil warming for climate change adaptation.

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