Nitrogen and Phosphorus Application Effect on Yield and some Characteristics of Date Palm in Minab Region

Date palm cultivation has played a valuable role in sustainability and life improvement of poor communities in rural and remote areas for a long time. Iran is the second largest producer of dates in the world with Minab regions of southern province of Hormozgan being the main producer. Cultivation of this crop is the main source of income for the majority of Minab’s farmers; to maintain this industry profitable, orchard management practices such as application of right amounts of fertilizers are required. Annually with each harvest, nutritional elements are removed from orchard soil at various amounts. On average, in one hectare orchard of 121 palms, 42 kg nitrogen (N) and 11 kg phosphorus (P) are taken away with annual harvest. If not replaced, this depletion could negatively affect the following crop loads and fruit quality. Therefore, in this experiment, with the aim of replenishing the soil nutrients, effect of application of different levels of N and P on fruit quality and crop load of Mordaseng, a cv. widely under cultivation in Minab, was assessed over successive fruiting cycles

This study was conducted as a factorial experiment in a randomized complete block design in three replicates using six-year-old trees of Mordaseng cv. at Minab Agricultural Research Station over six successive years. The aim of the experiment was to investigate the effect of N and P nutrients on yield and some characteristics of Mordaseng date palm cultivar. The independent variables were various levels of N (0.0, 150, 200 and 250 (g tree-1)) sourced from urea and pure P (P2O5) (0.0, 66 and 88 (g tree-1)) sourced from triple superphosphate, and the dependent variables were fruit yield and quality characteristics. The following amounts were yearly added to each level of N and P as trees grew older: 0.0, 60, 120 and 180 g for N, and 0.0, 20 and 40 for P.

The yield for N4P2 treatment gained the highest place in statistical group while for N1P1 treatment (excluding N and P) gained the lowest one. The highest fruit flesh weight (FW) and total soluble sugar (TSSu) were obtained for N4P1 treatment whereas the highest total soluble solid (TSS) was obtained from N2P3 treatment.

Application of N and P resulted in a significant increase in the yield comparing to control. Using the highest level of N (250 (g tree-1)) gave the highest fruit FW and TSSu percentage along the highest yield. Application of the highest level of P (88 (g tree-1)) produced the highest TSS percentage. Overall, these results revealed that the application of N and P significantly improved fruit yield and some quality criteria of Mordaseng cv. under the environmental condition of Minab region.