Effect of potassium application on Deglet Noor date production and quality

Traditionally date palm mineral nutrition in Tunisian oasis is based on organic matter given every four years. However, with news oasis extensions, growers start to use chemical fertilizers for their date palms. Potassium is one of the major mineral elements and it is a key element involved in fruit quality. Present experiment was established in a commercial garden of 'Deglet Nour' in Rjim Maatoug Area in South Tunisia, to study the response of date palm to potassium fertilization using potassium sulfate in reference to a control. Potassium was supplied by two ways: soil spreading or foliar spray at 2%. Results showed an increase of yield in response to K supply. Foliar spray of potassium also improved date quality. An increase of average fruit weight was observed from treated palms. Mineral analysis of leaves and fruits from the two treatments with potassium showed significant differences over control fruits.