Determination of potassium critical level in date palm leaf and effect of potassium on yield and quality of date fruit (cv sayer)

In order to determine the potassium critical level in date palm leaf, fertilizer experiments with four treatments from 4 levels of potassium, including: 0, 250, 500 and 750g K from potassium sulfate source were carried out in randomized complete block design with three replications on 24 date palm (c.v Sayer) in Khuzestan Province. Potassium critical level in date palm leaf was determined by Cate- Nelson graphical method and quantitative data and qualitative characteristics were analyzed using SPSS statistical program and the means of data were compared using Duncan’s Multiple rang test. Potassium critical level in date palm leaf, 0.95 percent, was determined by Cate- Nelson graphical method. Also, the results showed that potassium treatments had a significant effect on yield and some quantitative characteristics such as weight, diameter and volume of fresh fruit, weight of pulp and pulp to seed ratio of fresh fruit.