Gilbertella Rot of Peaches Caused by G. persicaria in South Carolina. C. Ginting, Department of Plant Pathology and Physiology, Clemson University, Clemson, SC 29634. E. I. Zehr, Department of Plant Pathology and Physiology, Clemson University, Clemson, SC 29634. Plant Dis. 76:753. Accepted for publication 4 March 1992. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/PD-76-0753D.
Rotted peaches (Prunus persica (L.) Batsch) with fruiting structures
characteristic of the Mucorales were collected from floors of 14
orchards in five South Carolina counties. Gilbertella persicaria (E.D.
Eddy) Hesseltine (1) was isolated more frequently than Rhizopus spp.
Representative isolates of G. persicaria mated with either NRRL 1546
(-) or 2357 (+) mating types of G. persicaria. The first symptoms
observed after inoculation of wounded peaches (cv. Redglobe) with
a spore suspension were tan lesions that appeared 2 days after
incubation at 21-24 C in closed plastic containers; after 5 days, fruit
were completely covered by sporangiophores and black sporangia.
Fruit incubated between 4 and 40 C showed symptoms at 16-34 C,
with 28 C the optimum. Symptoms of Gilbertella rot developed in
0-23.8% of peaches collected from packing lines and incubated at
21-24 C. This is the first known report of Gilbertella rot of peaches
in the southeastern United States.