Effect of Foliar Fertilization on the Characteristics of the Leaf Surface of Pear Varieties in the Arid Climate of the Astrakhan Region

The effectiveness of foliar fertilization – spraying leaves with solutions of macroand microelements on light chestnut soils of the region – on the characteristics of the leaf surface of various pear varieties was studied. The changes in leaf area under the influence of various nutrient solution compositions in the arid conditions of the Astrakhan region were analyzed in detail. We have studied 3 main indicators: the individual leaf area (cm2), the total leaf area per adult tree (m2/tree) and the leaf area per 1 hectare of plantings (m2/ha). The study was conducted at the experimental site of the Caspian Agrarian Federal Scientific Center of the Russian Academy of Sciences. The site was laid out in 2014. Records and observations were carried out in 2022–2024. The object of the study was 3 varieties of pears widespread in the region: Nadezhda, Krasavaya, Victoria, characterized by their drought resistance and demanding availability of nutrients. Solutions containing various combinations of macronutrients (nitrogen, phosphorus, potassium) and trace elements (boron, iron, zinc, manganese, copper), such as Aquarin, Ultramag Boron, and Ultramag Calcium, were used as foliar top dressing. An analysis of individual applications of micro-fertilizers showed that treatment with Aquarin alone of the Nadezhda variety led to a 94.4% increase in leaf area. This indicated the high effectiveness of this drug for providing plants with nitrogen and other macroand microelements important for leaf growth. The combined use of Ultramag Boron and Ultramag Calcium in the same Nadezhda variety proved to be less effective, demonstrating an increase of only 44.4%. This indicated a synergistic effect from the combined use of Aquarin with the preparations Ultramag Boron and Ultramag Calcium, where each drug complemented the action of the others, providing a more complete nutrition of pear trees.