Different doses of potassium nitrate applied through fertirrigation in papaya

Abstract

The aim of this work was to study the effect of the application of increased doses of potassium fertilization, using potassium nitrate as fertilized source. The studied crop was papaya, Formosa group, Tainung Nº 1 variety. The study was carried out at Distrito de Irrigação Jaguaribe Apodi (DIJA), Ceará, Brazil. It was used a randomized block design with three replicates. The treatments consisted on the application of four different amounts of potassium nitrate (69; 137; 172 and 206 kg KNO3 ha-1 month-1). This quantity represented the 50; 100; 125 and 150% of the recommended soil analyses. The analyzed tributes were: diameter of stem, length of fruit, average weight of the fruit, number of fruits per plant, productivity of the fruit and total levels of soluble solids in the fruit. The use of large dosages of potassium nitrate increases the number of fruits per plant until certain boundary-value, from now on the value of this variable starts to decrease. The application of large doses of the fertilizer increases the average length of the fruit