Yield traits of sunflower ( Helianthus annuus L.) hybrids according to the difference in their growth stages

摘要

The responses of sunflower hybrids to environmental conditions during vegetative and generative growth periods are different; these differences play an important role in seed yield. In this study, dry matter accumulation, stem diameter, number of leaves and plant height data of seven commonly used sunflower hybrids grown under irrigated conditions were regularly collected during growth periods uptill the harvest season. The effects of growth stage differences on yield traits were investigated. Dry matter accumulation of hybrids continued till the back of head yellowing period and the highest dry matter accumulation was obtained in seed filling period (R6) as 47.24 g m -2 day -1 . Dry matter losses of hybrids were at the highest level following the R7 period due to the fall of leaves which lost their functions, and dry matter content in R7 period was 17.04 t ha -1 , while it was decreased to 11.38 t ha -1 at harvest. Approximately, 5.66 t ha -1 dry matter loss was added to soil as organic matter. To conclude, LG 5585 hybrid had the biggest head diameter, highest number of seeds in a head, plant seed weight and 1000-seed weight, seed yield (3957.8 kg ha -1 ), harvest index (45.75%) and, consequently, the highest oil yield (1820.6 kg ha -1 ), suggesting that this hybrid could be used in irrigated lands for seed and oil production.