Approach to Yield Response of Young Almond Trees to Deficit Irrigation and Biostimulant Applications

Water is the most limiting resource in many semi-arid areas of Mediterranean countries. Among the strategies to improve water productivity, the implementation of deficit irrigation (DI) strategies and the introduction of drought-tolerant crops in irrigated areas (such as almond) are being widely studied. Recently, the use of biostimulants to enhance crop tolerance to drought under water-scarcity scenarios is increasing. This work examines the response of three almond cultivars (‘Guara’, ‘Marta’, and ‘Lauranne’) in terms of yield and associated physiological responses in the main phenological stages to biostimulants (HYT ？ A and HYT ？ B plus) applied to young trees subjected to different irrigation levels: (i) a full irrigation treatment (FI), irrigated at 100% of crop evapotranspiration (ET C); and (ii) sustained-deficit irrigation (SDI 75), irrigated at 75% of ET C. Significantly higher yields were obtained with HYT applications in 2 of 3 cultivars; these differences were most evident in the SDI 75 treatment. In particular, ‘Guara’ registered the most significant improvements in nut yield when the HYT product was applied (15–20% higher). With regard to crop physiological responses, higher values of leaf water potential and stomatal conductance were noted with the HYT application in some cultivars and phenological stages. These results indicated that the use of biostimulants can be a feasible strategy for almond cultivation, especially when SDI is used. View Full-Tex