Effect of Deficit Irrigation on Almond Kernel Constituents

The effects of deficit irrigation on almond fatty acid and tocopherol levels were studied in a field trial. Mature almond trees were subjected to three levels of deficit irrigation (85, 70 and 55%), compared to control (100%) and over-irrigation (120%). Two deficit strategies were used: regulated deficit irrigation (RDI) and sustained deficit irrigation (SDI). Results from two harvest years showed moderate deficit irrigation (85% RDI and 85% SDI) had no negative impacts on almond kernel lipid content. Moderate to severe deficiency, 70 and 55% had variable impacts on lipids. USFA and SFA fluctuated under the treatments and no fatty acid was resistant to water deficiency. gamma-Tocopherol levels were relatively stable under deficit irrigation but not alpha, beta-tocopherol and alpha-tocotrienol. The variation between years indicated climate has an effect on almond fruit development. We concluded it is feasible to irrigate almond trees using less water than the normal requirement, without the loss of kernel nutrition quality.