Determination Of The Appropriate Irrigation Interval Based On Soil Moisture Depletion Of Date Palm (Phoenix Dactylifera L.)

Abstract

field experiment was conducted in a date palm farm, southern Iraq, during the 2019 and 2020 seasons, and the purpose of the study was to determine the appropriate irrigation interval for date palms based on soil moisture depletion (SMD) and water consumption, and the effect of SMD on growth, yield and water productivity, three levels were used 30%, 40%, 50% as a percentage of total available water (TAW), from which three intervals were determined, the treatments were placed in a randomized complete block design with three replications. The depth of irrigation water that is applied on the basis of evapotranspiration for each treatment was 50, 66, 83 mm respectively, for SMD treatments. Analysis of variance showed that soil moisture depletion had a significant (P < 0.05) effect on the yield, annual growth of fronds, and water productivity. the highest average yield of dates is 34.2 and 37.2 kg.palm-1 for 30% SMD for the 2019 and 2020 seasons, with water productivity of 0.49, 0.53 kg.m-3, and the highest annual growth rate of fronds 20.22 and 26.40 cm.year-1 for the two seasons. In conclusion, although the date palm tolerates drought, it leads to a shortage of yield, due to the conditions of the study area. An irrigation interval is recommended when 30% of TAW is consumed with an irrigation depth of 50 mm to achieve the highest water yield with the highest yield and annual growth rate. Further research is also recommended in the field of SMD for palms for different conditions.