an evaluation of spring types of safflower genotypes for late season water deficit tolerance

expansion of oilseeds cultivation plays an important role in provision of the required edible oils for a country's population. iran is one of the origins safflower as a drought and salt tolerant crop, and therefore, it can be counted on as a suitable alternative crop for cultivation in marginal areas. the aims followed in the present research were on evaluation and selection of late season drought tolerant genotypes of spring types of safflower for cultivation in marginal areas under limited irrigation and to study the drought effects on yield and its components. the study was carried out at the east azarbaijan research center of agriculture and natural resources, iran (46? and 2? e, 37? and 58? n) during 2005. a factorial experiment consisting of 2 irrigation levels (non stress and drought stress during seed filling stage), and 5 safflower genotypes (local arak 2811, local esfahan, pi, kh23-57 and il111) and based on complete randomized complete block design of 3 replications was employed. the results indicated that rwc, paniculum height, no of seeds per paniculum, 1000 seed weight, harvest index as well as seed and oil yields significantly decreased while leaf temperature (t1) significantly increased as a result of water deficit. the rates of these traits differed among genotypes under water stress vs non stress conditions. a significant correlation was observed between seed yield and rwc, t1, plant height, paniculum hight, panicula per plant, seeds per paniculum as well as 1000 seed weight. it sounds like rwc and t1 can be used in selection of late season drought tolerant spring types of safflower. in addition, the traits no of seeds per paniculum and 1000 seed weight (in comparison with other components of yield), were more seriously affected by drought stress. local esfahan and local arak 2811 bearing higher seed yields were less affected in seed yield reduction as imposed by drought. these two genotypes are therefore decided as more suitable for cultivation in areas with late season stress, due to water deficit.