Qualidade de tubérculos frescos de cultivares de batata em função da nutrição fosfatada

Abstract

Phosphorus (P) is essential to increase tuber yield and nutritional quality of potato tubers. However, it is unclear whether the influence of P fertilization on quality of tubers produced can vary depending on the cultivar and P availability in soil. This study evaluated the effect of P fertilization on the quality and nutritional composition of marketable tubers of potato cultivars. Experiments in soils with low, medium and high P availability were conducted in a randomized block design, with four replications. Treatments consisted of a 2×5 factorial arrangement of two potato cultivars (Agata and Mondial) and five P2O5 rates (0, 125, 250, 500, and 1,000 kg ha–1). Phosphorus fertilization increased the contents of P and starch, the size and yield of marketable tubers, with more expressive response to higher P rates in the soils with low and medium P availability. The Mondial cultivar had the highest yield, due to a greater tuber weight and greater increases in this characteristic in response to P fertilization. The Mondial cultivar produced tubers with firmer pulp, with higher dry matter percentage and higher contents of Ca, Cu, and Zn than Agata. In the soil with low P availability, P fertilization reduced Zn content, but, in general, had little influence on the nutritional composition of potato tubers.

Phosphorus (P) is essential to increase tuber yield and nutritional quality of potato tubers. However, it is unclear whether the influence of P fertilization on quality of tubers produced can vary depending on the cultivar and P availability in soil. This study evaluated the effect of P fertilization on the quality and nutritional composition of marketable tubers of potato cultivars. Experiments in soils with low, medium and high P availability were conducted in a randomized block design, with four replications. Treatments consisted of a 2×5 factorial arrangement of two potato cultivars (Agata and Mondial) and five P2O5 rates (0, 125, 250, 500, and 1,000 kg ha–1). Phosphorus fertilization increased the contents of P and starch, the size and yield of marketable tubers, with more expressive response to higher P rates in the soils with low and medium P availability. The Mondial cultivar had the highest yield, due to a greater tuber weight and greater increases in this characteristic in response to P fertilization. The Mondial cultivar produced tubers with firmer pulp, with higher dry matter percentage and higher contents of Ca, Cu, and Zn than Agata. In the soil with low P availability, P fertilization reduced Zn content, but, in general, had little influence on the nutritional composition of potato tubers.

O fósforo (P) é essencial para aumentar a produtividade e a qualidade nutricional dos tubérculos de batata. Porém não se sabe se a influência da adubação fosfatada na qualidade dos tubérculos produzidos pode variar em função da cultivar e da disponibilidade de P no solo. O objetivo deste trabalho foi avaliar o efeito da adubação fosfatada sobre a qualidade e composição nutricional dos tubérculos comercializáveis de cultivares de batata. Foram conduzidos experimentos em solos com baixa, média e alta disponibilidade de P, utilizando delineamento de blocos ao acaso, no esquema fatorial 2 × 5, com quatro repetições. Os tratamentos foram constituídos por duas cultivares de batata (Agata e Mondial) e cinco doses de P2O5 (0, 125, 250, 500 e 1.000 kg ha–1). A adubação fosfatada aumentou o teor de P e de amido, o tamanho e a produtividade de tubérculos comercializáveis, com resposta mais expressiva às maiores doses nos solos com baixa e média disponibilidade de P. A cultivar Mondial foi mais produtiva, por apresentar maior massa média de tubérculos e maiores aumentos nessa característica em resposta a adubação fosfatada. A cultivar Mondial produziu tubérculos com polpa mais firme, com maior percentagem de matéria seca e com maiores teores de Ca, Cu e Zn do que a Agata. Em solo com baixo P disponível, a adubação fosfatada reduziu o teor de Zn mas, de maneira geral, teve pouca influência na composição nutricional dos tubérculos de batata.