ASSESSMENT OF INTRODUCED APPLE VARIETIES BY SCAB AFFECTION (VENTURIA INAEQUALIS (COOKE) G. WINTER)

Abstract

The article presents data on the identifying of apple varieties resistant to scab for their further use in breeding. The research was carried out on the basis of the Orenburg branch of the Federal Horticultural Research Center for Breeding, Agrotechnology and Nursery from 2010 to 2020 in the orchard established in 2004. The objects of research were introduced apple varieties and local hybrids. Scab (the causative agent is the marsupial mushroom Venturia inaequalis (Cooke) G. Winter) causes great damage to the apple tree. This disease affects the fruits and leaves, while dramatically reducing the apple productivity and marketability. According to the results of the studies, the greatest development of scab was observed in 2011, 2013 and 2016. In dry years (2010, 2012, 2014, 2015, 2017-2020 years) scab lesions were not observed. We have identified apple introduced varieties, which over the years of observation had a weak scab lesion and few spots on the apple leaves. In the control variant, in summer varieties in 2011, the scab on the leaves of the Serebryanoe kopytse variety was 0.9 points, all other studied varieties had a lower parameter. In autumn varieties, the varieties Sverdlovchanin and Gornist had the lowest parameter — 0.3-0.4 points, respectively, with a control parameter of 0.8 points (Prizemlennoye variety); in winter varieties, all the studied samples were lower than the control variant — 0.9 points. Weather conditions 2013 and 2016 also showed apple varieties less susceptible to scab in the conditions of the Orenburg region. As a result, we identified apple varieties that are weakly affected by scab: summer varieties — Letneye polosatoye, Mechtatel’nitsa, Solntsedar, Chudnoye; autumn varieties — resident of Sverdlovsk, Hornist; winter — Anis Sverdlovsky, Krasa Sverdlovsk, Persian. The obtained data can be used in breeding to create new apple varieties resistant to scab in the conditions of the Orenburg region.