Date of Award

6-2014

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Agricultural Education

First Advisor

Dr. Elke Neumann

Second Advisor

Dr. Shyam S. Kurup

Third Advisor

Dr. Kenneth B. Marcum

Abstract

In this study young clonal date palm plants were transferred into horizontal split-root pots filled with compost-amended soil of the UAE. The pots were constructed from two adjacent plastic containers, fastened together by adhesive tape. Once the plants had established new roots in the containers, the soil moisture level was measured every two to four days in all soil compartments. In the control treatment, the soil moisture level was brought to 30% w/w after soil moisture recording. Deficit irrigation treatments received exactly 60% of the average amount of water supplied to the pots of the control treatment. In the homogeneous deficit irrigation treatment, irrigation water was distributed over the two adjacent root compartments of each pot in a way that the soil moisture level was kept the same between the two parts of the plant root system. In partial root zone drying (PRD) treatments, irrigation water was supplied only to one of the two adjacent pots. The PRD treatments were shifted every 2, 4 or 6 weeks, in a way that the formerly dry soil part of each split root pot was irrigated, and the moist part fell dry. In the ‘permanent PRD’ treatment, water supply was not shifted, and only one compartment was irrigated throughout the experiment. The irrigation treatments were maintained for 240 days. By the end of this period, no visual differences could be detected between palms of the different irrigation treatments. Leaf elongation measurements did not reveal an effect of deficit irrigation on leaf growth. Though leaves of the control treatment grew faster during the first phase of development, they grew slower compared with the other treatments during later stages, so that in the end no significant differences in leaf length were detected. There were no differences in the nutritional status between plants of the different irrigation treatments, suggesting that date palms are very well able to take up nutritional elements from dry soil.

The result of this study indicate that date palms respond to high amounts of irrigation water supply with a severe reduction in water use efficiency. Since PRD and homogeneous deficit irrigation yielded the same results in term of plant growth and nutrient uptake, homogeneous deficit irrigation is recommended for date palm production, as it does not require the expansion of the existing irrigation system

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Horticulture Commons

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