Effects of corm planting density and manure rates on flower and corm yields of saffron (Crocus sativus L.) in the first year after planting

In order to investigate the effects of high corm planting density and applying manure on flower and corm yields of saffron (Crocus sativus L.), a field experiment was conducted at Research Station, Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, during growing season of 2010-2011. A completely randomized block design with three replications and 20 treatments was used. The experimental treatments were all combination of different planting densities of corm (100, 200, 300 and 400 corms.m 2) and different levels of manure application (0, 40, 60, 80 and 100 t.ha-1). Results of variance analysis showed that corm planting density and manure application rates had significant effects on flower number, fresh and dried flower and stigma+ style yields of saffron. In addition, mentioned characteristics of saffron significantly affected by interaction effects of corm planting density × manure rate. Based on the results, fresh and dried flower yields of saffron significantly increased by increasing planting density up to 400 corms.m-2. In addition, on planting density equal to 400 corms.m-2, increasing manure up to 80 t.ha-1 had significant effects on fresh and dried flower yields of saffron. However, the responding saffron to manure was decreased by reducing corm planting density. Therefore, it seems that appropriate manure application rate depends to corm planting density.