Nutrition, Yield and Quality of Tomato Fruits for Processing, Affected by Phosphorus and Potassium Fertilization

The industrial yield of tomato fruit (Solanum lycopersicum) depends on quantitative and qualitative factors, which may be influenced by phosphorus (P) and potassium (K) availability to plants. This experiment was carried out at the municipality of Janauba, Minas Gerais, Brazil, in an Oxisol with clayey texture, in order to evaluate the effects of phosphorus and potassium fertilization on the nutritional status of the plant, yield and some qualitative variables of tomato fruits (cv. IPA-5). The experimental design was a complete randomized block, in a four by four factorial arrangement (four rates of phosphorus and four rates of potassium) with four replications. The following rates of P were used: 0, 150, 300 and 600 kg ha(-1) of P2O5 (triple superphosphate); the potassium rates (2/3 at planting and 1/3 at the sidedressing) used were: 0, 50, 100 and 200 kg ha(-1) of K2O (potassium chloride). Phosphate fertilization increased P leaf contents and fruit production. Maximum marketable yield was produced with the (estimated) application of 293 kg ha(-1) of P2O5. The critical level of P in the leaves was 3.1 g kg(-1). Potassium fertilization did not affect any of the traits analyzed.