Bartlett Tree develops novel pest management for Beech Leaf Disease

Research scientists at the Bartlett Tree Research Laboratories – the research arm of the F. A. Bartlett Tree Expert Company – have developed novel Integrated Pest Management strategies to treat Beech Leaf Disease. 

“At times in the past seven years, while researching beech leaf disease, I’ve felt as if there would be no hope for management," says Andrew Loyd, plant pathologist and mycologist leading Bartlett’s BLD research. "But through painstaking and tedious work, we have now been able to find two successful treatment options: a foliar application program designed for smaller trees, and a root flare injection suitable for large trees. And, although frustrating at times, it has been a very rewarding process.” 

This follows the discovery and publication of the research team’s first successful foliar treatment option that targets the invasive microscopic worm, a nematode (Litylenchus crenatae mccannii), causing BLD. A new injectable treatment discovery shows excellent potential to protect larger beech trees for up to several seasons, staving off the defoliation and canopy dieback that results from severe infection. 

“It is important to keep our goals in mind with integrated pest management development,” says Matthew Borden, another plant pathologist on the research team. “This disease-causing nematode has spread at an astounding pace, quickly climbing into the ranks of other ecosystem-shifting catastrophes we have seen over the past century, like Chestnut Blight and Emerald Ash Borer. Where containment and eradication are no longer feasible, we strive to develop IPM tools and techniques to protect individuals or groups of susceptible trees.” 

While these discoveries and treatment options are not designed to address BLD at the forest level, scientists at Bartlett say many beech trees can be protected in places such as landscapes and arboreta, where beech are valued as shade trees.

The ongoing work of other scientists investigating the nematode’s life cycle, how it spreads and physiological impact on beech trees is also critical to finding future solutions. 

Bartlett’s new treatment builds upon the work of scientists and arborists who developed treatments for Dutch elm disease in the 1970s and 80s, particularly the “Tree Doctor” R. Jay Stipes, professor emeritus at Virginia Tech, as well as a good friend and mentor. Jay was thrilled that the chemistry and tree injection techniques he helped pioneer to preserve many elm trees will find new success against yet another tree epidemic. 

“BLD is unlike any other widescale tree disease we have ever had to face,” Dr. Borden adds. “As Jay likes to say, ‘Tree medicine, as human medicine, is an uncertain art.’ The nematode poses unique challenges we have had to overcome with out-of-the-box thinking. It takes a full year to properly evaluate a single treatment in the field, and we have conducted many field studies to test a wide range of management options and fine-tune treatments that show potential. The ongoing support of our research department, New England Division leadership, and especially Robert A. Bartlett, Jr. has made these discoveries possible.”