Articles
WHY IS COLLETOTRICHUM ACUTATUM A QUARANTINE ORGANISM, AND C. GLOEOSPORIOIDES AND C. FRAGARIAE ARE NOT?
According to EC guidelines this fungus is a quarantine organism, which may not be imported into the EC member countries. C. gloeosporioides and C. fragariae, which are also pathogenic on strawberries, are not listed as quarantine organisms.
Isolates of C. acutatum, C. gloeosporioides and C. fragariae are difficult to distinguish from each other.
In a phytosanitary inspection of imported plant material, Colletotrichum was found in young strawberry plants stored under special conditions, with 80% of the plants showing black, sporulating lesions on petiols.
It could not be determined which species of Colletotrichum was causing the disease.
In our opinion it is of no importance to know which Colletotrichum species, causing similar symptoms, destroyed these plants.
Colletotrichum fruit rot is becoming more and more of a problem in some strawberry growing areas of Switzerland.
Until now, it was assumed that the disease had been imported with young plants from neighbouring countries.
On the other hand, Colletotrichum sp. causing bitter rot on sweet cherries, apples, elderberries, blueberries, red currants and blackberries is well known and widespread in Switzerland.
It would be helpful to know:
- why C. acutatum is a EC quarantine organism, and C. gloeosporioides and C. fragariae are not,
- why Colletotrichum spp. are not on the quarantine list of EPPO,
- if C. acutatum is more aggressive, causing more damage on strawberry plants than the other Colletotrichum species,
- a simple, fast and reliable method to detect any Colletotrichum in symptomfree, latently infected plant material,
- if Colletotrichum strains pathogenic on cherries and other hosts can infect strawberries under field conditions.