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Disease Note. Phomopsis Dieback of Peach Shoots in Alabama. A. J. Latham, Department of Plant Pathology, Auburn University, AL 36849-5409. G. Morgan-Jones, and H. L. Campbell. Department of Plant Pathology, Auburn University, AL 36849-5409. Plant Dis. 76:426. Accepted for publication 7 October 1991. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/PD-76-0426A. During 1991, an epidemic of shoot dieback occurred in 75% of
the peach (Prunus persica (L.) Batsch) orchards in central Alabama.
Disease was observed as chlorotic, wilted, or necrotic leaves on shoots
girdled by the Phomopsis anamorph of Diaporthe pemiciosa Marchal
(syn. Phoma persicae Schulzer & Sacc.) (1). On 24 April, lesions were
found on 1-yr-old wood, with infections centered on buds. Diseased
and healthy shoots were counted on one limb per tree on each of
four randomly selected trees per cultivar in a 1 ,600-tree block. Cultivars
and percent disease were: Sentinel 96%, Coronet 89%, Redhaven 88%,
Topaz 80%, Loring 73%, Harvester 71%, Sure Crop 56%, Dixie Land
19%, and Redskin Elberta 5%. On 17 May, lesions were found at
the base of juvenile branch shoots. These infections appeared to result
from spores washed down the diseased shoots. Phomopsis dieback
has become a problem of increasing importance for Alabama growers,
since the pathogen rapidly destroys fruiting wood of susceptible peach
cultivars. |