EFFECT OF PHOSPHORUS, COPPER, AND ZINC ADDITION ON THE PHOSPHORUS COPPER AND PHOSPHORUS/ZINC INTERACTION IN LETTUCE/

The effect of phosphorus (P), copper (Cu), and zinc (Zn) addition on t he P-Cu and P-Zn interaction in lettuce (Lactuca sativa L.) was analyz ed following a factorial design. The experiment was conducted in a gre enhouse. Two levels of P (62 and 224 ppm), three levels of Zn (0, 0.17 , and 0.34 ppm), and three levels of Cu (0, 0.03, and 0.06 ppm) were a pplied in all combinations to lettuce grown in perlite. The influence of the different treatments on the leaf P concentration suggests that the P-Cu interaction was positive, whereas P-Zn was negative. An incre ase in root absorption and retention and a decrease in translocation t o leaves were observed for Zn and Cu when the nutrient solution was su pplied at a luxurious consumption level of P.