Yanovskii, Y.P. 2001 [The resistance of apple to San Jose scale.]. Sadovodstvo i Vinogradarstvo No. 1: 13-14.

Notes: Studies were carried out during 1993-99 in the central forest steppe zone of the Ukraine on the resistance of 47 apple cultivars to San Jose scale [Diaspidiotus perniciosus]. Generally, young trees were more resistant than old trees. Resistance varied between cultivars, with 100% resistance found in cultivars Rosavka, Sapphire, and Kiev Winter. A study on the development of the scale on cv. Rosavka showed a high natural resistance of this cv. to the scale.