Tomato genotypes grown under phosphorus deficiency stress

The increase in phosphorus absorption efficiency by tomato plants can lead to a reduction in the phosphorus fertilizer rates used, as well as, possibly, the immediate use of P fixed in the soil. Thus enabling consequences favorable to agricultural sustainability, net revenue of farmers and taking advantage of marginal areas. In this way, this study aimed to evaluate the efficiency of absorption and utilization of phosphorus in three genotypes of tomato plants grown on different levels of P2O5. It was used the randomized block design, in a factorial 3 x 5 (three tomato genotypes: Globonnie, Tom-598 and F1 [Tom-598 x Globonnie]) and five P rates: (0, 150, 300, 450 and 600 mg kg-1 soil), with four replications. They were evaluated in the study dry matter of root, stem, leaf, photosynthetic rate, content of green color using the portable chlorophyll meter SPAD, phosphorus content, absorption efficiency and phosphorus use efficiency. It is concluded with the research on tomato crops that increasing P2O5 doses provided: 1) lower dry matter of stem, root and leaf in F1; 2) higher intensity of the green color, measured by SPAD (portable chlorophyll meter) in Tom-598 and Globonnie; 3) higher photosynthetic rate in Globonnie; 4) higher phosphorus accumulation in Tom-598; 5) greater efficiency of phosphorus absorption and utilization, applied at lower doses in Globonnie and 6) higher efficiency of P utilization by Globonnie, independent of the dose used, demonstrating expression of the crt gene (Cotton root).