G. Morvan, C. Castelain
The decline of apricot trees represents a problem since at least 40–50 years. A definite explanation of this phenomenon has not yet been given; consequently, no satisfactory control has been proposed.

We meet difficulties of different kinds which contradict the important progress made in this domain.

First of all, there is a problem of terminology:

What may be reasonably called apricot decline or apoplexy?'/ Must we follow certain authors who give long lists of pathogenic agents, just as well infectious or not infectious ones, which they suppose able to provoke the decline? Nevertheless, we notice the same disease in other countries too, where the term decline is never used. We are thinking here particularly on the English speaking countries. Is the decline in fact a special phenomenon only known in apricot trees? Someones point out that cases of apoplexy occur also in other fruit tree species.

May be one or even several diseases reasonably considered as factors determining this decline?

The opposite ideas conceived by different authors give rise to a regrettable situation. We think that everybody will agree that this problem is a complex one. In order to resolve it, collective research is required which makes necessary for us to use a common language.

Morvan, G. and Castelain, C. (1969). CONNECTIONS BETWEEN INFECTIOUS AGENTS AND APRICOT TREE DECLINE. Acta Hortic. 12, 153-180
DOI: 10.17660/ActaHortic.1969.12.6