Recent Outbreak of Phomopsis Leaf Blight, Caused by Phomopsis obscurans, on Strawberry Petioles and Stolons in Connecticut. W. H. Elmer, Department of Plant Pathology and Ecology, Connecticut Agricultural Experiment Station, Box 1106, New Haven 06504. . Plant Dis. 74:331. Accepted for publication 26 February 1990. Copyright 1990 The American Phytopathological Society. DOI: 10.1094/PD-74-0331D.
An outbreak of disease symptoms appeared in 1989 on strawberry
(Fragoria × anonassa Duch.) petioles and stolons in commercial fields
in Connecticut. Symptoms included sunken reddish elliptical lesions
thai in many cases girdled the petiole and killed the leaflet. Petiole
lesions resembled those of leaf scorch caused by Diplocarpon earliana
(Ell. & Ev.) Wolf and anthracnose caused by Colletotrichum spp.
However, isolations from petioles on potato-dextrose agar yielded
Phomopsis obscurans (Ell. & Ev.) Sutton (syn. Dendrophoma
obscurans (ElL & Ev.) Anderson). The foliar infection phase of the
disease had been common but minor in previous years. That phase
appeared as reddish brown spots with light to brown centers that
expanded into elliptical lesions (1-3 cm) with purplish halos or
advanced along major veins producing V-shaped lesions. Inoculations
of healthy leaves with conidial suspensions of P. obscurans produced
similar foliar lesions, and the fungus was reisolated. The economic
impact of the petiole and slOlon infection phase may be greater than
that of the foliar infection phase in Connecticut (1).