Foliar contents and establishment of dris index for the cupid potato cultivar

Potatoes tend to have relatively short production cycle and high yield per area, hence they demand the presence of readily available nutrients in soil solution. Each potato cultivar has specific characteristics of its development. The objective of this study was to verify foliar contents and to establish Diagnosis and Recommendation Integrated System (DRIS) indices for the Cupid potato cultivar with the use of organo-mineral fertilizer. The experiment was conducted in Perdizes city, Minas Gerais, during the rainy season of 2014/2015. The experimental design had randomized blocks with factorial arrangement of 4 doses and 2 fertilization managements + control treatment (conventional mineral dose) with 3 repetitions. The organo-mineral fertilizer doses were 25, 50, 75 and 100% of a mineral dose, which were: 600 kg ha-1of potassium sulfate, 850 kg ha-1of phosphate monoammonium, and 300 kg ha-1 of ammonium sulphate. The management of fertilization consisted of either performing or nottop dressing 19 days after planting (DAP) with hilling. After 36 days, leaf samples were collected from each plot for foliar analysis. At the end of the experiments, the tubers were collected to calculate the productivity of the useful area on the plots. The order of insufficiency can be established using DRIS in the high productivity group through the following sequence: Fe>S>K>Mn>Cu>Zn>B> Mg>N>P>Ca, and the order of insufficiency in the low productivity group through the following sequence: Mn>P>N>Mg>Fe>Cu>Zn>S>K>B>Ca. On the basis of DRIS, the treatment with the dose of 75% and top dressing showed the best nutritional balance in the production of potato cv. Cupid.