EFFECT OF SEED PRIMING AND FOLIAR APPLICATIONS OF P IN TOMATO SEEDLINGS

Abstract

The objective of this study was to evaluate the effect of different sources and forms of application of phosphate fertilizers on the initial growth of tomato (cv. Moctezuma F1) under greenhouse conditions. The sources consisted of commercial liquid fertilizer (FL), soluble monoammonium phosphate (MAP), and phosphoric acid (H₃PO₄), which were applied as pretreatment to seeds (seed priming) and foliar spray at a concentration of P₂O_5. of 240 mg L^-1. In the first case, the seeds were subjected for 24 h to solutions prepared with the different sources, while the foliar applications were made when the first true leaves appeared. The seeds were established in expanded polystyrene trays, using peat moss as substrate. For the statistical analyses, a completely randomized design with a 4 × 2 factorial arrangement (four sources of P and two forms of application) was considered, giving a final combination of eight treatments with five repetitions. The experimental unit consisted of 11 seedlings. The variables evaluated were the fresh and dry weight of the aerial part (leaf + stem) and root, stem diameter, SPAD units and the foliar concentration of N, P and K. The results indicate that there was no interaction between the factors studied in all the evaluated variables, except for fresh and dry root weight. In general, the applied treatments showed favorable results in the foliar application method. The results indicate that it is possible to favor the initial growth of tomato seedlings by applying P fertilizer sources, mainly through foliar applications of FL and MAP.