الفهرس 
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Abstract
Sunflower ( Helianthus annuus L . ) is one of the third most important oil crop in the world. It is the main source of edible oil in many countries, Argentina, Rumania, Turkey, France and Italy that due to its wide range of adaptability in addition to the high percent of excellent edible oil in the seed (45-55 %).
Sunflower became the third oil seed crop grown in the world (after cotton and soybean) although it is the second liquid oil produced and consumed in the world. The cultivated area in the world was about 25843104 million hectares and total production was about 37449403 million tons,
The total cultivated area in Egypt during 2012, season was about 7472 hectares and total production was about 20098 tons
In Egypt, due to the sever shortage of edible oil, sunflower received agreat (attention from the high authorities since of 1987). The local production of oil satisfies 5 % only of the total requirements of the country. The total annual consumption of edible oil is about one million ton. For increasing the total production of edible oil,and the area. cultivated with oil crops such as sunflower should be increased, high yielded hybrids should be planted and the best agricultural practices such as plant population and phosphate solubilizing bacteria, mycorishiza fungi should be conducted.
Agronomic practices such as plant density are known to affect crop environment, which influenced on the yield and yield components (Almas Zaid) et al., (2002). Plant density affected on plants characters and growth and development pattern.Optimum population levels of plants should be maintained to exploitmaximum natural resources, such as nutrient, sunlight, soil moisture and to ensure set is factory yield. On the other hand, inorder to increase grain yield, density must be kept at proper plant population (EL. Hi ty et al., 1994). The seed yield of sunflower increased to the maximum with increasing plant density and remained constant at even high plant density under favorable environmental conditions. Under less farorable conditions however, the grain yield tended to decline at very high plant desity (Barros. et al., 2004).
Phosphoras (P) is an essential plant nutrient required for higher and sustained. Productivity of oil from sunflower, Its influeneed or seed yield, oil yield and oil quality has been well established and application of phosphorus has become an essential part of sunflower fertilizer program (Zubillaga et al., 2002).
In general, phosphorus is added to soil as inorganic phosphates, because the free inorganic pin soil solution plays a central role in P cycling and plant nutrition (ekin, 2010). Phosphate solubiling bacteria (phosphorein) and fungus. (Arbuscular Mycorrizal) have the capability to mobilize phosphate, micro- nutrients and to promote root development and there by enhance nutrient up take (Mahaveer et al., 2000). Phosphate solubilizing bacteria plays a fund a mental role in correcting the solubility, problem in soil by transforming the insoluble phosphate to soluble forms by secreting organic acids such as formic, acetic, lactic, propionic, fumaric, and succinic acid. (Abou. Khadrah et al., 2002).
Moreover, Mycorrhizae fungi are essential factor in the sustainable soil- plant system, that are symbiotic with more than 97 percent root of plant. Mycorrhizal fungi receiving energetic corbon resources form plant, fungus facilitates the uptake of many inorganic nutrients such as phosphorus, Zinc, molybdenum, copper and iron. The symbiotic relalionship between mycorrhizal and plants is one of the most a bundant symbiotic activities in plant kigdom) which exists in most of the ecosystems (Vaseghmanesh et al., 2013). Soliman (2010) reported that inoculation of mycorrhizal in sunflower increased head diameter, seed yield and oil yield.
Therefore, the study aimed to:
Evaluate the effect of plant density and P- bio fertilization on the yield and its components and oil yield as well as to evaluate the effect of interaction between plant density and P- bio fertilization on yield it,s components and oil yield to find out the best treatment that realize the highest yield and oil content.