Physico-chemical characteristics of potato tubers in function of the doses and time of nitrogen and potassium application

Abstract

The present work was carried out aiming to evaluate chemical and physical characteristics of potato tubers in function of the doses and time of nitrogen and potassium application. Three doses of N and K (75% of the recommended dose; recommended dose according to soil analysis; 125% of the recommended dose; recommended dose according to soil analysis) and five application times were used (100% upon planting; 1/3 upon planting and 2/3 upon tuberization; 50% upon planting and 50% upon tuberization; 1/3 upon planting, 1/3 upon tuberization and 1/3 25 days after tuberization; 1/4 upon planting, 1/4 upon tuberization, 1/4 25 days after tuberization and 1/4 50 days after tuberization) and. The experimental outline was the factorial one (3 × 5), with plots arranged in randomized blocks with four repetitions. Tubers from the Agata cultivar, uniformly budded. Firmness was assessed, as well as soluble solids, total titulable acidity, total soluble sugars and reducing sugars. The data were submitted to the variance analysis and Tukey teste at 5% of probability. Only the application time and the doses of N and K did promote significant responses in the content of reducing sugars in the tubers potato Agata.