Effect of irrigation during grain filling stage and applying phosphate on the photosynthetic efficiency and yield of winter wheat in the fluvo-aquic soil area Effects of endophyte infection on tall fescue in different phosphorus levels and forms INFLUENCE OF DIFFERENT PHOSPHORUS LEVELS ON SOME BIOCHEMICAL CHARACTERISTICS IN CYMBIDIUM SINENSE FOLLOWING PHOSPHORUS STARVATION EFFECT OF PHOSPHORUS LEVEL ON NITROGEN ACCUMULATION AND YIELD IN SOYBEAN Effects of Different Phosphorus Levels on Photosynthesis and Root Nodule Nitrogen-fixing Characteristic of Alfalfa Effects of phosphorus levels on chlorophyll fluorescence parameters of wheat (Triticum aestivum L.) with different phosphorus efficiencies Effect of the nitrogen and phosphorus levels and meteorological conditions on formation dynamics of grain protein content in spring wheat EFFECTS OF DIFFERENT PHOSPHORUS LEVELS ON GROWTH, DEVELOPMENT AND SOME PHYSIOLOGICAL CHARACTERISTICS IN CYMBIDIUM SINENSE FOLLOWING PHOSPHORUS STARVATION Effect of phosphorus levels on soybean phosphorus nutrition,yield and quality