Identification of critical P level for sunflower in solution culture for P acquisition

Abstract

Solution culture experiment was conducted during November 2012 at ICAR-Indian Institute of Oilseeds Research, Hyderabad with a protocol to identify the critical level of phosphorus (P) in nutrient solution suitable to produce initial growth of sunflower that could be able to distinguish the deficiency effect from sufficient level. The study showed that 2.0ppm P was found to be critical in solution to arrest the normal growth of shoot, root, dry matter and P uptake at 30 days of sowing. The regression coefficient obtained between total dry matter and P levels in solution culture was found be to highly significant (R2=0.97). The best fit curve through quadratic equation was found to be Y= -0.0496x2+0.713x +0.5932. The results obtained in this study would provide the basis for conducting rapid screening of sunflower genotypes for P acquisition and identification of distinct changes in root modifications against P stress or starvation during the initial plant growth period (up to 30-45 days).