Development of a new protocol for a sustainable foliar nutrition in almond orchards
The almond market is experiencing a period of steady growth in terms of both production and consumption. In Italy, the interest in almond cultivation is increasing, as confirmed by the presence of new almond orchards in areas not fully suited to its cultivation and where the knowledge of plant behaviour related to soil and climate conditions is still poor. Optimizing fertilization is one of the most important factors to guarantee high yields and nut quality, as well as to reduce environmental pollution. The trial was established in 2019 in a commercial orchard located in Viterbo province (Italy), with the aim to evaluate the effect of total foliar nutrition applications on almond trees compared to plants managed applying traditional soil fertilization as a control. Plants were subjected to four foliar nutrition applications with two different foliar fertilizers containing macro- and micro-nutrients. The effects of foliar nutrition were evaluated in the second year of trial (growing season 2020) by applying foliar diagnostics, the deviation from optimum percentage (DOP) for each nutrient, and eco-physiological traits such as leaf chlorophyll and flavonol levels and the nitrogen balance index. Furthermore, the yield efficiency was also calculated. No differences were observed for leaf nitrogen, potassium and calcium concentrations between treatments, while the average concentrations of phosphorus and magnesium were higher in plants subjected to foliar nutrition than in the controls. In general, the concentrations of micronutrients in the leaves, as well as the nut yield, were higher in plants subjected to foliar nutrition. The experiment is still in progress and will contribute to develop a sustainable protocol for nutrition in almond orchards, limiting the environmental impact caused by the addition of fertilizers to the soil.
Pica, A.L., Silvestri, C., Tofi, D., Pierini, E. and Cristofori, V. (2022). Development of a new protocol for a sustainable foliar nutrition in almond orchards. Acta Hortic. 1333, 307-316
Prunus dulcis (Mill.) D.A. Webb, mineral nutrition, leaf diagnostics, DOP index, yield efficiency