INFLUENCE OF PLANT IMMUNITY INDUCERS ON APPLE CULTIVARS GOLDEN RANGERS AND IDARED YIELD IN THE CONDITIONS OF THE REPUBLIC OF ABKHAZIA

Abstract

The inclusion of immunity inducers in the technology of agricultural crops cultivation activates growth processes that lead to an increase in yield up to 30–50 %, however, the effectiveness of these drugs is regional and variety-specific. The purpose of the research is to assess the effect of immunity inducers on the productivity of Golden Rangers and Idared apple varieties when inducers are included in the protecting crops system from scab in the Republic of Abkhazia. The study of the effectiveness of immunity inducers on apple in the conditions of Abkhazia is carried out for the first time. The studies were carried out in 2016–2019 on the basis of the Institute of Agriculture of the Academy of Sciences of Abkhazia. The experiment was laid in the experimental apple orchards (planting in 2013, planting pattern 3 × 1.5 m, area 1 ha, stock M9 on a trellis with drip irrigation) in the Gulripshsky district of Abkhazia on varieties that differ in the degree of resistance to apple scab — susceptible Idared and the relatively resistant Golden Rangers. The experiment included immunity inducers of various chemical nature — Albit ® (poly-beta-hydroxybutyric acid, 6.2 g/kg), Immunocytophyte ® (ethyl ester of arachidonic acid, 0.167 g/kg); Ecogel ® (chitosan lactate, 30 g/l). The inclusion of these immunity inducers in the apple trees cultivation technology steadily increased for 4 years the average fruit weight and yield in the tested varieties compared to the variant of adopted in the region technology. The influence of the studied preparations on the weight of fruits and the increase in yield turned out to be variety-specific. The maximum values of the increase in fruit weight were noted in the third and fourth years of the experiment — on the Idared variety up to 10.1–24.3 % and on Golden Rangers variety up to 13.5–19.4 % compared with the economic processing (standard variant). The scab-susceptible Idared variety showed the maximum yield increase in the second year of the use of immunity inducers, while the Golden Rangers variety showed more stable yield increase in all years of the experiment. All variants with plant immunity inducers showed higher yields than in the case of economic treatment (standard variant). Among the immunity inducers, Albit ® stood out, which increased the yield relative to economic treatment by 22.6–82.9 %, and Immunocytophyte ® was the least effective (the increase was 9.9–58.8 %).