Influence of plant immunity inducers on the degree of apple scab development when applied in plant protection systems in the zone of humid subtropics of Abkhazia

Abstract

One of the ways to reduce pesticide load and prevent emergence of pathogen resistance can be the use of plant immunity inducers in plant protection systems. The purpose of these studies was to evaluate an efficiency of natural plant immunity inducers Albit® (poly-beta-hydroxybutyric acid), Immunocytophite® (arachidonic acid ethyl ether) and Ecogel® (chitosan lactate) in apple scab protection systems in Abkhazia. The maximum resistance of apple trees to this phytopathogen was recorded in the experimental variants with Albit® and Ecogel® application in half dosages of fungicides and in the variant of production processing (biological efficiency reached 79.4 %). Plant immunity inducers used on apple trees showed cultivar-specificity. For the four-year research period, the greatest efficiency of immunity inducers was achieved on the susceptible cultivar Idared in the second year of the experiment, while on the relatively scab-resistant cultivar Golden Rangers – it was achieved only in the third year. The greatest stability in the efficiency for a four-year period was observed for the tank mix Albit with half dosages of fungicides. Immunocytophyte® was characterized by lower inducing activity, which is associated with its activation of the jasmonate pathway for the formation of non-specific induced immunity.