Efficiency of copper-containing fungicide in protecting apple trees from scab under the conditions of the Orel region

The aim of the research was to improve the phytosanitary condition of young apple orchard through the use of fungicide Abiga-Pik, VS (400 g/l copper chloroxide) against fungal diseases. The research was conducted on trees of resistant and medium resistant to scab of apple varieties Antonovka Obyknovennaya, Orlovskoye Polosatoye and Veteran, trees without fungicide treatment served as control. The garden was planted in 2021 according to the scheme 3,0 x 5,0 m, height of trees was 1,5-1,7m. The stock apple was 54-118 semi-dwarf. The plants were treated with fungicide Abiga-Pik, VS (400 g/l copper chloroxide) at the rate of 50 ml/10 litres of water with a knapsack during the period of bud isolation - the beginning of inflorescence, during the period of ascospores beginning of summer. The disease was counted by means of continuous survey of plantations during the whole vegetation period every 10 days on 5 trees of each variety in threefold repetition. In 2024, the disease developed more rapidly than in the previous year, and prevalence on control variants without fungicide application was higher between 4 and 8% compared to 2023. The Antonovka Obyknovennaya and Orlovskoye Polosatoye varieties are more resistant to the scab pathogen compared to the Veteran variety, which is confirmed by the prevalence of the disease and the degree of damage. On trees of the Veteran variety, the disease incidence was maximum and it was 86% in 2023 and 94% in 2024. The degree of damage also exceeded this indicator for other varieties and it was 3.1 and 3.5 points, respectively. Biological efficiency of fungicide Abiga-Pik, BC was 62.8% in 2023 and 59.6% in 2024. Biological efficiency of the drug application in average for two years for Antonovka Obyknovennaya variety was 71.5%, for Orlovskoe Polosatoye variety was 73.7%.