PHYSIOLOGICAL INDICATORS PEACH RESISTANCE TO UNFAVORABLE FACTORS OF SUBTROPICS RUSSIA

Abstract

The results of long-term studies of various introduced varieties of peach grown on the field and characterized by early fruiting, resistance to destabilization of weather conditions in the subtropical zone of the Krasnodar Territory are presented. The purpose of the investigation is to assess the functional state of peach plants, their resistance to changes in weather conditions on the Black Sea coast.  Variety study of the Persica vulgaris (Mill.) collection is carried out at the Federal Research Center of the Subtropical Scientific Center of RAS (Sochi), on the basis of the Laboratory of Plant Physiology and Biochemistry. Field work is carried out on an area of 0.5 ha on test peach trees. Landing pattern 5 ? 2 m, 2011 trial establishment. Crown pruning is V - figurative with annual cosmetic pruning for fruiting. For physiological and biochemical studies were used Redhaven (control), Bellao Dio Cesena (early ripening), Rich Lady (medium ripening), Bolero (medium ripening), Gladis (late ripening), Michelini (late ripening) varieties. The varietal resistance of peach to unfavorable environmental conditions was assessed by a set of indicators (the thickness of the leaf blade, water deficit, hydration of leaf tissues and photosynthetic activity). The objects of study were physiologically mature peach leaves, selected in triplicate - 7 - 9th from the base of the shoot. Application of fertilizers in doses of N₁₂₀P₉₀K₉₀, without irrigation of plantations. The soil of the site is brown forest, 60 cm deep, humus content 1.39 - 2.95%, pH = 6.49 - 7.86 [1]. The selection of peach leaves for physiological analyzes was carried out from the beginning of June to September, depending on the variety, the timing of leaf growth and the onset of stress conditions (drought, high air temperatures). During the study of peach plants a high water deficiency of leaves was noted in Gladis, Michelini and Bolero varieties, which exceeded Redhaven (st.) by 1.3 times, and low water content of leaf tissues was established (lower by 3.7-6.1% in comparison with the control), which characterized them as less resistant to abiotic environmental factors. It was revealed that regardless of the water-thermal disturbance among the tested plants, the varieties Redhaven, Bellao Dio Cesena and Rich Lady contained a significant amount of carotenoids, reaching 0.3-0.4 units, which confirmed their adaptability to unstable weather conditions of the subtropics of Russia.