Response of Young Peach Trees to Ambrosiella sulphurea, a Symbiotic Fungus of Xyleborinus saxeseni. Joe Kovach, Cornell University, IPM Support Group, New York State Agricultural Experiment Station, Geneva 14456. Clyde S. Gorsuch, Department of Entomology, Clemson University, Clemson, SC 29634. Plant Dis. 72:225-227. Accepted for publication 8 September 1987. Copyright 1988 The American Phytopathological Society. DOI: 10.1094/PD-72-0225.

Young peach trees were infected with Ambrosiella sulphurea, a primary ambrosia fungus of the ambrosia beetle Xyleborinus saxeseni, using two different inoculation techniques. Primary and secondary growth, flower bud set, and yield of peach trees were monitored. Percent discoloration in woody tissue was calculated and nutrient composition of peach leaves observed between treatments. Trees infected with A. sulphurea had 22% more secondary growth and 138% more discolored wood than control trees. Primary growth varied according to inoculation technique used. Yield and flower bud set were not affected by A. sulphurea. Nutrient composition of leaves from control and infected trees was similar for most minerals analyzed except Ca, Fe, K, Mg, and Mn, which were higher in leaves from infected trees than in those from control trees. These levels were within sufficiency ranges for normal peach tree development, however. Results from this study indicate that peach tree decline observed in association with X. saxeseni is not due to A. sulphurea.

Keyword(s): peach diseases, peach insects, plant injury, wounds, Xyleborus.