اثر تنش كمبود آب و تراكم بوته بر عملكرد و برخي از صفات مورفولوژيكي و فيزيولوژيكي آفتابگردان

Effects of Water Deficit Stress and Plant Densities on Yield and Some Morphological and Physiological Characteristics of Two Sunflower (Helianthus annuus) Hybrids

Effects of water deficit stress and plant densities on yield and some morphological and physiological characteristics of two sunflower {Helianthus annuus) hybrids was investigated. The experiment was conducted as a split factorial based on randomized complete block design whit three replications at Research Station of the Islamic Azad University of Tabriz in 2006. Treatments were Reccord and Azarghol, four levels of water used were control, 75%, 50%, 25% of available soil moisture and plant densities of 80, 90 and 100 thousands plants per hectare. Row spacing was 60 cm and plant intervals within rows were 16, 18 and 20 cm, respectively for the three plant densities. Results indicated that imposing achenes to drought stress decreased seed and oil yield per m2, weight of fruit wall, empty seed weight and content of chlorophyll (p<0.01). Furthermore, effects of variety on levels of stress was significant in seed and oil yield per m2, empty fruit weight. Azarghol and Reccord under control condition produced highest seed yield and oil yield per m2. Results also indicated that the effects of plant densities on seed yield per m (p<0.01) was significant. Azarghol and Reccord at 10 plant densities per m2 had the highest seed yield per m and Azarghol and Record at 8 plant densities per m2 had the least seed yield per m2 . Results also indicated that Azarghol hybrid by 90000 plants /h-1 and Reccord at 100000 plants per hectare at 25% available water had highest and lowest empty achenes, respectively.