Laboratory testing of grapevine yellows in Slovenia indicates a widespread presence of bois noir

Abstract

Grapevine yellows are dangerous diseases caused by different types of phytoplasma. The two most important types are Flavescence doree (FD) and Bois noir (BN). Infected grapevine express exactly same type of symptoms regardless of the type of the phytoplasma. In order to control the grapevine yellows it is essential to know the phytoplasma type, which provides basic information for choosing proper and efficient control measures. Only the laboratory testing methods provide tools for the determination of the phytoplasma type. The testing included the vines expressing more or less typical disease symptoms. In majority of vines which tested positively, we were able to determine the phytoplasma type. The results showed the widespread presence of the BN phytoplasma in all wine growing regions of Slovenia.