INFLUENCE OF WATER STRESS, PHOSPHORUS AND ZINC APPLICATIONS ON, SEED QUALITY AND SEED YIELD OF SUNFLOWER (Helianthus annuus L.)

Two field experiments were conducted during 2007 and 2008 summer seasons in the farm of the Faculty of Agriculture, MansouraUniversity, to evaluate the influence of water stress, phosphorus and zinc fertilization on, seed quality, seed yield and yield components of sunflower crop using a split-split plot design with 3 replicates. The experimental field treatments were 24. The results showed that, water stress significantly decreased seed yield, 100- seed weight, seed oil and protein contents as well as seed contents of N, P, K and Zn. Whereas mineral P combined with phosphorus solubilizing bacteria (PSB) increased them except seed content of Zn which decreased with mineral P application and increased with PSB application. Foliar application of chelated zinc increased the above mentioned parameters except seed content of P. It could be concluded that for producing a high yield and a good quality of sunflower seeds, it must be considered a suitable program of water stress, bio and mineral fertilization of P and Zn.