Potassium and Nitrogen Fertigation Frequency on Pineapple Yield and Fruit Quality

Pineapple is a nutritionally demanding crop, with emphasis on potassium and nitrogen nutrients. In this context, the aim of this paper was to study the effect of nitrogen (N) and potassium (K) fertigation frequencies on the physical-chemical fruit characteristics of ‘Pérola’ pineapple crop. The experiment was conducted in a randomized block design, with 18 treatments and 4 replications. It was used a factorial scheme (4 × 4) + 1 + 1, which represents- four N fertigation frequencies applied by surface drip irrigation (4, 7, 27 and 54 times throughout the crop cycle); four K fertigation frequencies (4, 9, 35 and 70 times); one additional treatment (irrigated, but without fertigation); and one control (non irrigated and non fertigated). The fruit characteristics analyzed were- fruit mass with crown, yield, soluble solids, pH, titratable acidity and SS/TA ratio. The N fertigation frequencies had no effect on variables evaluated, however, the K frequencies had a significant influence on fruit mass with crown, yield and pH. The results showed that the effect of K frequencies applied through fertigation on pineapple yield and fruit physical-chemical quality was more pronounced in comparison to the effect of N applications. Monthly potassium fertigations, followed by four applications throughout the crop cycle, provided the greatest increase in fruit quality, allowing higher values of fruit mass, yield and pH.