Impact of Superabsorbent Materials on Fruit Quantity and Quality Characteristics of Zahedi Date Palms under Deficit Irrigation Condition

To study the effect of different drip irrigation regimes and superabsorbent materials on the fruit quantity and quality characteristics of Zahedi date palms, a field experiment was carried out in split plot arrangement using randomized complete block design with three replications. Deficit irrigation treatments with three levels including 100%, 75%, and 50 percent crop water requirement based on the Ntional Water Document were in the main plots and superabsorbent treatments with three levels including without superabsorbent (control), use of Aquazorb superabsorbent (300 g per date palm), and use of Zeolit superabsorbent (4 kg per date palm) were in the sub plots. The results of analysis of variance showed that the effect of deficit irrigation on fruit weight, fruit length, water productivity, and potassium, and the effect of superabsorbent materials on fruit length, potassiom and total sugar was significant at 1% level. Also, intraction effects of deficit irrigation and superabsorbent materials on fruit weight and potassium content (at p<1%) and on the fruit length (at p< 5%) was significant. Use of superabsorbent materials in condition of irrigation with 100% crop water requirement did not have a positive effect on the quantity and quality characteristics of date fruit. But, under irrigation with 75% and 50% crop water requirement, superabsorbents significantly improved some quality characteristics of the fruit. Water productivity with 75% crop water requirement increased by 29.4% as compared with the 100% treatment, and use of Aquazorb and Zeolit superabsorbents increased water productivity (14.5% and 17.7 percent, respectively) as compared with the control. In general, irrigation with 75% crop water requirement (with consumption of 8052 m3 ha-1) and use of Zeolit superabsorbent for date palms (Zahedi cultivar) is suggested for Ghasreshirin area.