Bartlett Tree Experts makes progress in fight against Beech Leaf Disease
Research scientists at the Bartlett Tree Research Laboratories – the research arm of the F. A. Bartlett Tree Expert Company – have broken new ground to protect beech trees by developing novel Integrated Pest Management (IPM) strategies to treat Beech Leaf Disease (BLD).
“At times in the past seven years, while researching beech leaf disease, I’ve felt as if there would be no hope for management,” said Dr. 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 successfully 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 Dr. 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 now feel confident that we can protect many beech trees in places such as landscapes and arboreta where beech are valued as shade trees, historic specimens, and represent genetically diverse collections that should be preserved for future work.
Over time, the scene will change, leading to the development of new resistant or tolerant beech varieties. In addition, Bartlett will continue to develop new management strategies to conserve beech culture. 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.
“BLD is unlike any other widescale tree disease we have ever had to face,” said Borden. “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.”
