investigation on the effect of biofertilizer, chemical fertilizer and plant density on yield and corm criteria of saffron (crocus sativus l.)

abstract in order to investigate the effect of biofertilizer, chemical fertilizer and plant density on yield and corm criteria of saffron, an experiment was conducted as complete randomized block design in a factorial arrangement with three replications under field condition in agricultural college, ferdowsi university of mashhad during 3 years of 2007,2008,2009. treatments included nitroxin biofertilizer ( a mixture of free-living nitrogen-fixing bacteria azospirilum sp./ azotobacter sp.), dalfard fertilizer ( a commercialized saffron fertilizer with 12% n from urea and nitrate sources, 8% p, 4%k and also zn, cu, mg, fe, chelates) and control with five corm density 4, 6, 8, 10 and 12 t ha-1. results indicated that effect of fertilizer treatment was significant on number of flower , dried and fresh flower weight, dried and fresh stigma weight during experimental year. effect of fertilizer treatment was significant on number of corm, dried and fresh corm weight during second experimental year. the highest number of flower, dried flower weight, dried stigma weight and dried corm weight was shown in dalfard and the lowest number of flower, dried flower weight, dried stigma weight and dried corm weight was obtain in nitroxin. the effect of different densities was significant on number of flower, fresh flower weight, dried flower weight and dried stigma weight during second year. the highest dried stigma weight was obtained in 8 t ha-1 in second and third year. regression results showed that with increasing the number of corm, dried corm weight was decreased.