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Disease Note.

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).

Reference: (1) J. L Maas. Adv. Strawberry Prod. 4:l4. 1985.