Abstract:
In Hungary, the most important disease of stone fruit tree species is induced by the Prunus necrotic ringspot virus (PNRV). The most severe economic damage occurs on sour cherry.
In the early 1960s, the average PNRV infection ranged from 3 to 5% in the central nuclear stocks and in the increase blocks.
The infection of orchards and gardens was more severe, reaching almost 100% at certain locations.
As a result of the National Certification Scheme for the production of virus-free fruit propagation material, PNRV infection has been reduced to 0.1–0.3% in the central nuclear stocks and to 0.02–0.1% in the increase blocks.
The infection of sour cherry plantations and gardens in the 1960s was compared to that of the 1990s with representative surveys.
The average infection level was reduced from 69% in the 1960s to 14% by the early 1990s.
A new symptom, enation on the leaf surface, has been also observed on heavily infected trees.
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