Study on the effect of different amounts application of NPK on quantitative and qualitative characteristics of date palm cv "Sayer" in Khuzestan Province.

Khuzestan Province is considered as one of the important regions of date production in Iran. According to agriculture statistic book of Iran (2003-2004), mature date plantation area and production of this province are 26000 hectares and 142,000 tons, respectively. Among the date palm varieties in province, Sayer date palm with more than 68 percent of date palm plantation area is one of the most commercial varieties. The yearly average of production for this variety is reported approximately 60-70 kg for each tree that this production is low. Then finding solution for this problem is necessary. In order to increasing quantitative and qualitative characteristics of date palm (cv Sayer), this experiment with twelve treatments from mix of 3 levels of net nitrogen including: 700,1000 and 1300g from urea source, 2 levels of phosphorus including: 500 and 650g from triple super phosphate source and 2 levels of potassium including: 1000 and 1300g from potassium sulfate source carried out in randomized complete block design with four replications on 48 date palm (c.v Sayer) during 2004-2008 in Khuzestan Province. In this experiment, fertilizer treatments along with 20 kg of manure and micronutrient chemical fertilizers based on general recommendation applied for each tree in winter by soil application method. The number of 20-25 leaflets from middle leaf of second row took, and mineral nutrients of them analyzed, each year. At fruit harvesting time, the yield, and quantitative characteristics such as: weight, length, diameter and volume of fruit fresh, weight of seed and pulp to seed ratio and qualitative characteristics such as: pH, acidity, brix, reducing sugar, total sugar and fruit moisture measured. Data analyzed with MSTATC statistical program and means of data compared with Duncan's Multiple rang test. The results showed that Treatment No.6, including: yearly application of 700g N, 500g P2O5 and 1300g K2O due to the highest yield, quantitative and qualitative characteristics of date fruit is the best treatment.