Water Relations and Photosynthesis in Phosphorus Deficient Mulberry Plants

Phosphorus deficiency in mulberry plants grown in sand culture decreased leaf area and chlorophyll content. Significant decreases in leaf water potential, stomatal conductance, transpiration and degree of succulence, and increase in water saturation deficit suggested water stress in phosphorus deficient plants. Although, phosphorus deficiency did not affect the leaf intercelluar concentration of CO₂ significantly, it increased CO₂ compensation point and decreased net photosynthesis, saturation concentration of intercellular CO₂ and stomatal limitation, suggesting that the effect of phosphorus deficiency on photosynthesis was non-stomatal.