Evaluation of tolerance chilling stress of winter and spring safflower cultivars for grain yield in Farahan region

This study was carried out in order to comparison of tolerance chilling stress and grain yield in prechilling spring cultivars with winter safflower cultivars in field of farahan university in Markazi province in 2006. A randomized complete block design with three replications was used 10 number of prechilling spring cultivars and 18 number of winter safflower cultivar: (Padide, S-6-46, LRV-51-13, LRV-51-20, 697, LRV-290, K.W.2, Yenice, LRV-51-11, K.C.72, K.A.72, IL-128, Marand local variety, L.S.P, IL-119, IL-111, Miandoab local, Gila, uc-1, Nebraska-10, Esfahan local variety, Arak-2811, FO2, Davari-2811, ES.68, IL-111(2), LSP(2), LRV-51-51. Each plot consisted of 2 rows, 5 m long with 50cm between rows and 5cm between plants on the rows. Some important characteristics such as: plant height, umber of branches per plant, number of grain per head, 1000-seed weight and grain yield were recorded. The results indicated that 697 cultivar with (2691 kg/ha), LRV-51-20 cultivar with (2062 kg/ha) cultivar and, K.C.72 with (2043 kg/ha) grain yield were significantly superior to the other treatments. The purpose of use prechilling spring cultivars to define least on new cultivar for planting in autumn in climate Farahan region.