EFFECT OF PLANT DENSITY ON GROWTH AND YIELD OF TWO SUNFLOWER VARIETIES

This work carried out during 2006 and 2007 summer seasons at the Experimental Farm, Faculty of Agriculture, MinufiyaUniversity in a spilt plot arrangement with three replications. To investigate the effect of some different types of plant density treatments i.e., 17000, 35000 and 70000 plants per faddan, with different space of culture, on growth, yield and its components and quality characteristics of two sunflower (Helianthus annuus, L.) varieties i.e., Vitoflower and Earoflower, which grown under two different plant spacing and number of plant per hill. The application of the various tested plant density treatments caused significant differences in all studied traits except most of flowering date and oil percentage. The treatment of 17500 plants per feddan when sown in 60 × 40 cm with one plant per hill gave the highest values for the most vegetative growth, yield and its components as well as oil yield. Variety Vitoflower was better than cv. Earoflower in all studied characters i. e. vegetative growth, seed yield per plant and oil percentage; on the opposite the variety Earoflower gave the highest values of head diameter and 100-seed weight traits which lead to increase seed and oil yields per feddan. The maximum sunflower seed production with good quality was obtained by the application of the interaction between plant density 17500 plants per feddan (when sown in 60 × 40 cm space of culture with one plant per hill) and variety Earoflower. It can be concluded from this study that, the optimum plant population for the achievement of maximum yield of sunflower under the conditions of this study lies between 17500 plants per feddan with 60 x 40 cm space of culture and 3500 plants per feddan with 60 x 20 cm space of culture and single plant per hill.