Harmfulness of the plum moth (Grapholitha Funebrana Tr.) in different types of plum plantations in the Northern Forest-Steppe zone of Ukraine

Abstract

Goal. To study the degree of fruit damage by the plum moth in different types of plum plantations. Methods. Entomological studies were carried out in 2012–2016 on Oda, Stanlei, and Bohatyrska varieties, grafted on clonal rootstocks of BVA1, Evryka, and seed rootstocks (cherry plum seedlings). The field method was used, which involved periodic determination of fruit damage by the moth in summer (once every 10 days) and monitoring of the seasonal dynamics of the flight of the plum moth, which was carried out with the help of pheromone traps. Statistical processing of research results was carried out using the Statgraphics Plus computer program package. Results. During the research period (2012–2016), seasonal dynamics of moth flight were observed with an average of 5.7–8.4 (2012–2014) and a maximum number of 9.0–14.1 imago/trap in 7 days per season ( 2015–2016). Damage to the fruits of the fruit drop of Grapholitha funebrana was mainly determined by the number of imago generations that had overwintered. The degree of damage to the fruits of the harvest depended significantly on the summer generation of the moth. The greatest damage to fruits was observed in years with a higher intensity of flight of pest butterflies (2015–2016). The Stanlei and Bohatyrska varieties had a lower level of fruit damage compared to the variety Oda. It was established that the damage of fruit drop by the moth (53%), and that of plum fruits (48%) depended on weather predictors and their interaction with varieties. It was noted that the plum yield was mainly influenced by varieties and weather conditions. Conclusions. It was proven that in the zone of the Northern Forest-Steppe, in different types of plum plantations, the seasonal dynamics of the flight of the plum moth was of 2 types — with the average and maximum number of imago during the growing season. The harmfulness of the fruit moth and the productivity of plums mostly depended on weather predictors and their interaction with varieties.