Біологічна та економічна ефективність мікробних препаратів проти борошнистої роси (Podosphaera Leucotricha Salm.) на яблуні в умовах Західного Лісостепу України

It was established that the studied biological preparations in the conditions of the Western Forest Steppe of Ukraine in 2021–2022 showed high effectiveness against apple powdery mildew. The disease manifested itself in the period from the «bud extension» phenophase to the «pink bud» phenophase, affecting 1.5–1.6% of apple leaves. Further, the level of disease spread increased during the flowering of the apple tree to 3.4–4.1%, at the end of flowering — to 6.5–9.6%, in the «period of fruit formation» — to 9.8–17.9%, in the phenophase of «fruit growth», when the fruit was the size of a hazel — up to 12.6–18.0%. In the «fruit growth» phase, when the fruit was the size of a walnut, the level of powdery mildew spread reached values of 15.3–18.1% of the affected leaves. The highest efficiency was obtained when using the preparation Fluorescin BT, at the rate of 2.0 l/ha in the «fruit growth» phenophase, when the fruit was the size of a walnut — 73.0%. The lowest efficiency was obtained from the use of Fitosporin BT, r. at the rate of 5.0 l/ha and Bactophyt BT, r. at the rate of 3.0 l/ha in the «pink bud» phenophase — 43.4%. The use of the Bactofit BT preparation, r. in the norm of 3.0; 4.0 and 5.0 l/ha reduced the development of powdery mildew by 43.4–69.5% 7 days after treatment. The yield with the use of this preparation was from 11.5 to 11.6 t/ha. Efficiency of use of Fluorescin BT, r. in the norm 1.0; 1.5 and 2.0 l/ha 7 days after spraying was 49.2–73.0%, with yields from 11.5 to 11.6 t/ha. When using the preparation Fitosporin BT, the norm is 5.0; 7.0 and 10.0 l/ha were effective against apple powdery mildew 7 days after spraying in the range of 43.4– 61.5%. The yield with the use of this preparation was from 11.5 to 11.6 t/ha. For the use of the preparation Ampelomycin BT, r. in the norm 2.0; 4.0 and 6.0 l/ha, the efficiency 7 days after treatment was 45.1–68.6%, and the yield was from 11.4 to 11.6 t/ha. Effectiveness of Topaz 100 ES fungicide, k.e. at the rate of 0.4 l/ha, which was used as a chemical standard, against powdery mildew was 83.6–86.7%, with an apple yield of 12.1 t/ha. Research and calculations have shown that the largest conditional net income and the highest profitability were obtained from the use of the preparation Fluorescin BT, r. — 1743.0–2448.0 UAH/ha and 167.3–212.5%. The payback threshold of this preparation was the lowest and showed that to cover the costs of applying the preparation, an increase in yield of 0.11–0.15 t/ha is necessary. When using the preparation Bactofit BT, they received conditional net income in the amount of UAH 573.0–1083.0/ha, at a profitability level of 26.9–55.4%, and the payback threshold was 0.19–0.28 t/ha. Threetime application of the preparation Ampelomycin BT, r. made it possible to obtain conditional net income in the amount of UAH 453.0–693.0/ha, profitability from 23.8 to 33.6% and a payback threshold of 0.150.32 t/ha. The lowest income among the preparations used against powdery mildew was obtained from the use of Fitosporin BT, r. — from 369.0 to 873.0 UAH/ha, with a profitability level of 15.8–47.8%. The payback threshold for the use of this preparation is 0.20– 0.34 t/ha, which is the highest among the studied preparations.