Evaluating of chemical phosphate fertilizers and Phosphor solublizing bacteria on seed yield, biological yield and tissues relative phosphorus content in winter rapseed (Brasssica napus L.)

Phosphorus is an important essential macronutrient required by all plants for growth, development and reproduction. Most agricultural soils in Iran have inadequate P for producing rapeseeds (Brassica napus L.). In these conditions we have two main sources of phosphorus fertilizers for winter rapeseed. Those are biological and chemical sources. In order to study of the influence of phosphor suloblizing bacteria as biological nutrient growth regulator and ammonium phosphate as chemical phosphorus fertilizer on rapeseed yield a field experiments was conducted during September 2007 to October 2008 at the experimental station of Arak Islamic Azad University, Arak, Iran. Phosphor solublizing bacteria at 4 levels (no use, one time use at seeding time, one time use at spring growth and dual use at seeding and also spring growth times) and ammonium phosphate at 3 rates of application (0, 50% and 100% recommended fertilizer according the soil test results used in sowing date) for rapeseed are made the treatments and arrangement as a factorial on randomize complete block design. The results showed grain yield and harvest index had significant difference for chemical fertilizers treatments at 5% levels. Generally, phosphorus contents at vegetative, reproductive and seed maturity stages showed significant increase with biological phosphate treatments.