عنوان مقاله [English]
An investigation was carried out on yield, yield components and some agronomic traits evaluation of sunflower cuJtivars, as Randomized Complete Block Design at 4 replications in Khoy as summer second cropping in Agriculture Jihad Research Station during 2003. In this experiment 12 sunflower varieties including 4 commercial hybrids, I lysun-33, Azargol, Allstar, Euroflor, 6 new Three Way Cross hybrids, RI03* Fl/7, Rl03* Fl/2, Rl03* Fl/16, R95* Fl/26, Rl03* Fl/l,Rl03* Fl/18, and two open-pollination varieties, Record and Armavirecki, were planted in Tir eleventh (2 July). Experimental results revealed significant difference among the features of the varieties indicating remarkable diversity of the varieties traits in summer second cropping and the possiblity of choossing the excellent variety among them. Among experimental varieties, hybrid Rl03* Fl/7 with average growing season of 93 days, and Record variety with average growing season of 104. 5 days were early and delay ripening varieties respectively. New T. W. C. hybrids with average growing season of 93-96 days, were early ripening than all of the commercial hybrids except for Allstar hybrid. This hybrid with 94 days of growing season had no significant different with new hybrids. Record variety enjoyed remarkable plant height among other varieties excluding Euroflor and Allstar varieties, but other varieties showed no significant difference as regards this feature. The highest tray diameter was seen first in Hysun-33 hybrid, and then in Record and Rl03* Fl/26 hybrid. Weighty seeds with average test weight of 57.70 and 57.19 were seen in Record and Hysun-33 varieties and the greatest number of seeds in tray were also seen in aforesaid varieties. The highest seed yield related to Hysun-33 hybrid with average 4004 Kg/ha but due to lowness of oil percent in this hybrid (41.16 %) Record variety with oil yield of 1839 Kg/ha comes first among others and Hysun-33 hybrid with oil yield 1646 Kg/ha comes second. Then come Azargol and R95* Fl/26 hybrids with respective average seed yield of 3116, 2967 and oil yield of 1515, 1347 Kg/ha as far as the amount of this feature is concerned. Studying of correlation yield and yield components showed that there exists a positive and strong correlation between seed yield and test weight. The experiment results showed that due to the region's conditions, planting of delay ripening varieties such as Record and Hysun-33 on timely and prematurely can have the highest seed yield and oil yield. But if there is limitation of planting season, early ripening hybrids such as R95* Fl/26 and R103* Fl/18 without having significant difference in terms of seed and oil yield with above mentioned varieties, are suitable for cultivation as second cropping in region. Provision of new hybrids with enjoy of early ripening, high seed and oil yield, can lead to the expansion of area or sunflower planting in the region.