Nitrogênio, fósforo e potássio no estado nutricional, produtividade e qualidade do maracujazeiro amarelo

Abstract

The culture of yellow passion fruit is extremely important for President Prudente SP region and the second region in terms of production in the state of São Paulo. Proper mineral nutrition for the plants is important to obtain high yields, coupled with the quality of fruit. Thus this work aimed to study the mineral nutrition with nitrogen, phosphorus and potassium and its effects on the chemical characteristics of the soil, nutritional status of plants, fruit quality, production and export of nutrients in yellow passion fruit plants. The experiment was conducted in a factorial split ½ x 4³ NPK with 32 treatments: 4 doses of N: 150; 300; 600; 1200 kg ha-1 N having to supply ammonium nitrate (32% N); 4 doses of P: 200; 400; 800; 1600 kg ha-1 P2O5, source superphosphate triple (42% P) and 4 doses of K: 150; 300; 500; 700 kg ha-1 K2O with the fertilizer potassium chloride (60% K). The parameters analyzed were: soil chemical, levels of macronutrients and micronutrients leaves and fruit; productivity ha-1; production of commercial fruits; percentage of commercial fruits; fruit classification; total number of fruits; average fruit weight; pulp yield; brix; pH of the juice; titratable acidity, vitamin C; shell thickness; fruit length and the export of nutrients with fruit. In the soil, nitrogen fertilization influenced the availability of phosphorus and sulfur. N rates increased the N content of the leaves, hence the nutrient influences the characteristics of shell thickness, commercial percentage, production of commercial fruits and classification, subsequently assisting in the export of N by the fruit of passion fruit. The maximum export N with fruit was 106.76 kg ha-1 for an estimated yield of 43.02 Mg ha-1. The phosphorus fertilization increased the P content of the soil, with the maximum availability of P obtained was 238.78 mg dm-3 in the dose 1600 kg ha-1 of P2O5. The P rate also increased the concentration of S in the leaves. The doses of P2O5 increased the total number of fruits. The interaction of N and K2O interfere in K soil levels. The K2O doses showed no effect on the nutrient content of the sheet and the nutritional status of fruit consequently, there was no answer in the export of nutrients to the fruit. However, potassium improved the percentage and production of commercial fruits, classification and caused decrease in vitamin C content of the pulp.