TATYANA NIKOLAEVNA DOROSHENKO*, GALINA FEDOROVNA PETRIK, LYDMILA
GEORGIEVNA RYAZANOVA, SERGEY SEMENOVICH CHUMAKOV AND NIKOLAY
Kuban State Agrarian University, Kalinina Street, 13, Krasnodar, 350044, Russia
*(e-mail : firstname.lastname@example.org; Contact : +7 (861) 221-57-76)
(Received : March 25, 2020; Accepted : May 20, 2020)
In the present paper, the authors substantiated the possibility of optimization of the formation of mandarin plant (Miyagawa-Wase variety) economic yield with the use of new agents at the final stages of fruit
development : Melafen growth regulator and Controlfit Phosphorus-Potassium (potassium phosphite) fertilizer. Laboratory and field experiments in the fruiting stands of mandarin in Russian humid subtropics (Sochi, brown forest soils) were carried out. According to the results of these experiments, the application of the tested agents 40 days prior to the fruit collection did not have a noticeable effect on the growth rate of plant shoots? At the same time, treatment of plants with Melafen, as well as foliar nutrition with phosphorus-potassium fertilizer, led to an apparent improvement in the indicators of generative activity : an increase in the number of fruits preserved on the plant, their average weight, and, ultimately, the economic yield. Moreover, the use of Melafen led to a more significant increase in the economic yield, while the use of potassium phosphite increased the average weight of the fruits. At the same time, both agents contributed to the acceleration of their maturation to a certain degree. The late-summer Melafen treatment, which stimulated an excessively intense movement of plastic substances from leaves to generative organs, led to a weakening of the photosynthetic activity of the leaves of evergreen mandarin plants and their resistance to stress factors during further development. At the same time, the use of potassium phosphite did not cause serious functional disorders in mandarin plants and did not affect their resistance to stress factors. The authors had concluded that the use of this fertilizer for the optimization of the generative activity of mandarin in humid sub-tropics was promising.
Key words : Humid sub-tropics, mandarin, new agents, economic yield, fruit mass, pigments, resistance, stress factors