NITRATE UPTAKE BY CORN UNDER INCREASING PERIODS OF PHOSPHORUS STARVATION

Single cross seedlings of the male progenitor of the double cross hybr id, BR 201, were grown for seven days in a complete nutrient solution prior to evaluating the kinetics of nitrate uptake under varying perio ds of phosphorus deficiency. Nitrate uptake decreased 60% after a shor t period of phosphorus starvation (2 days) and ceased when phosphorus was withheld longer than six days. Nitrate uptake resumed after phosph orus (P) was re-supplied, but the time required and extent of recovery depended on the length of phosphorus starvation.