Potential Relationship between Peach Tree Short Life Symptomology and Aberrant Wood Anatomy

Abstract

Peach tree short life (PTSL), a major disease complex impacting peach culture in the southeastern United States for decades, accounts for millions of dollars of losses annually. In spite of the overwhelming amount of research that has been conducted on PTSL, many uncertainties still exist regarding the factors involved in the syndrome and the true cause of tree death. As a consequence, we examined the wood structure and anatomy of 6-year-old peach trees, some showing the initial visible symptoms of PTSL, and others that appeared unaffected and healthy. Very dramatic differences in wood anatomy were observed between healthy and stricken trees. Stricken trees showed a total lack of vessel formation in some earlywood zones, a decrease in vessel formation in latewood, and a marked increase in ray parenchyma cells. Healthy trees showed normal vessel and ray formation. Preliminary results indicate that in some way PTSL may be associated with increased gum production in the xylem and decreased earlywood vessel production, thereby significantly reducing water conduction, leading to tree death. Results of studies currently in progress to further investigate this hypothesis will also be presented.