On January 27, 2011, “Al from Dadeville” called into the Paul Finebaum Show, a syndicated sports radio program, to boast that Auburn fans would not be enjoying the traditional rolling of the two iconic live oaks (Quercus virginiana) at Toomer’s Corner much longer because, to retaliate for the University of Alabama’s 2010 Iron Bowl loss to cross-state rival Auburn University, he had poisoned them with Spike 80DF. What followed was a five-year ordeal that only ended in February 2016 with the replanting of 10 progeny of the original live oaks located at Toomer’s Corner.
No one expected the call to be anything more than a disgruntled Alabama fan venting frustration after the Crimson Tide went ahead 24-0 before losing 28-27 at home. Even so, Charlie Crawford, then-AU Superintendent of Landscape Services, and Auburn Horticulture Professor Dr. Gary Keever collected soil samples the following day in the presence of Jimmie Cobb, a representative of Spike 80DF manufacturer Dow AgroSciences. The samples were delivered to the Alabama State Pesticide Residue Laboratory, located on Auburn’s campus, and that launched an official investigation that entailed the collection of duplicate samples by the Alabama Department of Agriculture & Industries (ADAI). Because of a December 2010 explosion that had damaged Alabama’s pesticide lab, however, the samples were forwarded to the State Lab in Mississippi for analysis. Two weeks later, the ADAI confirmed the soil samples tested positive for Spike 80DF.
Spike 80DF. The Toomer’s oaks were poisoned with Spike 80DF herbicide. The active ingredient in this herbicide is tebuthiuron, a member of the substituted urea group of herbicides. When applied to soil around vegetation, the herbicide is absorbed by the roots, translocated within the xylem, and carried upward into the foliage where it remains.
Upon entering the foliage, the herbicide becomes lethal in that it inhibits photosynthesis by blocking the movement of electrons (i.e., energy) between the two chlorophyll photosystems within the membranes of the chloroplasts. Energy flow stops immediately. The secondary step, which occurs as a result of the blockage, also can be very damaging itself. With the block in place, the energy that had been collected by the chlorophyll cannot be “moved on down the line,” but instead is dissipated as heat, readmitted as light, or reacts with oxygen.
Reaction with oxygen results in the formation of hydrogen peroxide, which in turn results in superoxide radicals, better known as free radicals, that are very damaging to membranes. With membrane integrity lost, cells collapse, and the tissue appears burned, leaf margins, where the tebuthiuron would have accumulated in the highest concentration, are rendered necrotic in appearance, and leaf tissue between the veins is yellowed. Plants have no ability to counter the effects of tebuthiuron.
Once the herbicide reaches the foliage, damage will result if photosynthesis is occurring. These herbicides have no biological activity other than blocking photosynthesis, and thus have minimal toxic effects on mammals. In addition, tebuthiuron is practically nontoxic to birds, fish, and other aquatic species.
Tebuthiuron is unique in that it is more persistent and more water soluble than other substituted urea herbicides. While this precludes tebuthiuron from having any utility in agronomic crops, it makes it ideal for the control of vegetation, including trees, along highways, railroads, parking lots, and utility rights-of-way. In these situations, soil longevity and the ability to become dispersed within the soil profile become assets.
Testing, Remediation, and Decline. Toomer’s Corner is where College Street and Magnolia Avenue intersect and where town meets gown in Auburn. In 2011, the University’s corner was anchored by brick portals donated by the Class of 1917 and two 85-year-old live oaks in approximately 300-square-foot beds surrounded by a large brick plaza. This corner of Samford Park is where the post-victory ritual of rolling the trees with toilet paper plays out . It is also where the poisoning occurred. Following confirmation of the poisoning, a task force of horticulturists, soil scientists, foresters, engineers, and chemists was quickly formed. At that time, task force members did not know when, where, or how much herbicide was applied. What was known was that the aggregate samples showed tebuthiuron levels of 0.78 and 14.6 ppm in one bed and 43.5 and 51.7 ppm in the other bed. According to Dow AgroSciences, 100 ppb is lethal to live oak. What followed was a series of measures to determine the distribution of the herbicide beyond the beds, to minimize further movement of the herbicide in the soil and uptake by the Toomer’s Oaks, to remove the herbicide from the beds, and to prolong the lives of the trees.
Two days after the poisoning was confirmed, a grid system was set up over and around the plaza, and soil samples were collected and shipped to Illinois for testing. Beds also were covered with tarps to exclude water and barricaded to reduce access (image 2). Results indicated limited contamination outside the beds, suggesting that the herbicide was applied only within the beds and that movement of herbicide beyond the beds resulted from foot tracking, movement in rain or water applied to remove toilet paper, or both (image 3). After soil samples were collected, the tree beds were drenched with liquid activated carbon in an attempt to bind herbicide in the beds until the soil could be removed, and the tree canopies were sprayed with anti-transpirant to reduce further uptake of herbicide.
In late February tents were constructed over the two beds and soil was removed from around the roots, first with an air-spade and then with high-pressure water and a vacuum truck to minimize water movement into the soil.
Prior to 2008, when the two beds were enlarged and the plaza resurfaced, tree roots within the beds were greatly restricted by concrete curbing. Soil removal from the part of the root system previously bound by curbing was extremely difficult due to the density of roots, in sharp contrast to the enlarged areas of the beds (image 4a, 4b or 4c). Samples were taken from the soil that was removed as well as from undisturbed soil at the limits of excavation. Roots were sprayed with liquid activated carbon, backfilled with a mix of topsoil and powdered activated carbon, watered, and mulched. Herbicide levels were very high (4 to 7 ppm) in bed samples taken from undisturbed soil, and the decision was made to remove more soil. By using higher-pressure water and a super-vacuum truck in the second removal, soil was removed as deep as four feet in places, although the dense root masses still created problems (image 5). Herbicide levels in samples collected from undisturbed soil in the beds following the second soil removal were much lower (1 to 16 ppb in one bed and 23 to 132 ppb in the second) or undetected, but there were doubts that levels were as low within or below the root mass.
From the first announcement of the poisoning, the Auburn University’s Office of Communications and Marketing began fielding questions about the safety of the Auburn drinking water. While the ground water beneath Toomer’s Corner doesn’t flow into the City’s drinking water source, the University had five wells drilled and 15 three- or four-foot borings, which were fractioned into one-foot sections, made on the plaza and in the adjoining Samford Park to alleviate concerns. Relatively low levels of tebuthiuron were present in any of the fractioned borings, and either were not detected or detected in the low parts per trillion in the water samples. The ground water was not considered a source of contamination of the City’s drinking water.
The first symptoms of poisoning — heavier than normal flowering and fewer immature leaves — appeared on the live oak closest to College Street in late March 2011. Fruit would set but abort before maturing. By early May, immature foliage, and, to a lesser extent, mature foliage, was chlorotic with burgundy margins. These symptoms progressed to foliar necrosis and leaf drop. A new flush of shoot growth typically appeared before leaf drop or soon afterward.
Throughout the summer and fall, the trees went through repeated cycles of leaf drop and reflushing, with each cycle less vigorous than the previous. By late September, canopies were only 20% to 30% that of healthy live oaks (image 6), and by January 2012, the College Street tree was completely defoliated (image 7). Task force members didn’t know whether the trees would leaf out in spring, but if they did, the focus would be on stimulating growth in hopes of promoting photosynthesis.
Beginning in March 2012, as the trees began to break bud and leaf out, and continuing through May the two beds were drenched with 300 gallons each of a 100 ppm N complete fertilizer + micronutrients and with 200 gallons of a compost extract (EarthMax/HuMAX) every two to three weeks. Insecticidal drenches and directed trunk sprays were applied in April and June to control ambrosia beetles. Also in March and May, the root flares of the trees were injected with 20 to 25 gallons of a 1.5% sugar solution (2 glucose: 2 fructose: 1 sucrose) and a 10% sucrose solution, respectively. There was no visible response to these measures, other than a temporary greening of the foliage, and trees continued to decline over summer.
The University allowed the rolling of the Toomer’s Oaks in fall 2011 but required that toilet paper be removed by hand instead of with adjustable-pressure water hoses, a process known to be deleterious to the trees. In June 2012, Auburn’s Tree Preservation Committee met with upper administration to discuss the development of a landscape plan for the corner, one that included replacing the trees. Removal was not to occur until after the 2012 football season and one last rolling.
By August, shoot dieback was extensive in both trees. To minimize potential injury to fans during rolling, the trees were pruned before the beginning of the fall term (image 8). The trees never flushed after being pruned. The 2012 football team won only three games, all non-conference. Following the victory over Alabama A&M, the trees were rolled, but later that evening, the toilet paper was either accidentally or intentionally set on fire, scorching the remaining foliage in the canopy, the bark and rhizomic shoots at the base of the trees (image 9). If not after the pruning, the trees were now aesthetically dead.
The Final Rolling of the Toomer’s Oaks occurred following the spring 2013 inter-squad football game with an estimated 80,000 fans participating (image 10a or 10b). Three days later, the trees were removed (image 12). In 2014, three feet of soil beneath the plaza and six feet where replacement trees were to be planted was removed, and a designed landscape was installed that included Silva Cells, a sand-based soil similar to that found in live oaks’ native range, seat walls, and an expanded plaza. Two 14-inch DBH replacement live oaks from a South Carolina nursery were root-pruned, dug, shipped, and planted at Toomer’s Corner on Valentine’s Day 2015 (image 11a or 11b). However, one tree declined and was replaced by a similar-sized live oak from Florida in July. Both trees now appear healthy, but spring and summer will indicate how they are adapting to their new environment. The University is optimistic they will be ready to roll by fall 2016.
Al from Dadeville. On February 17, 2011, Auburn University held a press conference on the steps of Samford Hall, the main administrative building, to announce that Harvey Updyke, alias “Al from Dadeville,” has been arrested and charged with the poisoning of the Toomer’s Oaks. Updyke, a retired Texas state trooper and a rabid Alabama fan who had named his daughter Crimson Tyde and his son Bear Bryant, was charged with criminal mischief, desecrating a venerated object, and damaging an animal or crop facility. As a part of a 2013 plea agreement, Updyke pled guilty to the Class C felony of damaging an agriculture facility. He served six months of a three-year sentence, was placed on five years of supervised probation, and was ordered to pay more than $800,000 in restitution to Auburn, plus court costs and legal fees. As of February 2016, he had paid $2,284.
The Future. The poisoning of the Toomer’s Oaks was a disruptive and costly personification of a rivalry gone awry. The replacement trees, however, appear healthy and in good condition, have a greater volume of soil to expand into, and are better situated to anchor the Class of 1917 portals. The plaza is more expansive and includes a new arching walk that will soon be lined with seedlings from the original Toomer’s Oaks. Other trees on campus are more appreciated and protected.
Since the poisoning, AU Facilities Management has incorporated more rigorous and expansive tree protection measures into its Design & Construction Standards, including costly penalties. The first ISA-certified arborist has been hired to manage campus trees, and the University was recently recertified as a Tree Campus USA. While many of these changes are small steps, cumulatively, they speak well for the future of trees on Auburn University’s campus.
Dr. Gary Keever is the Tom Dodd, Jr. Endowed Professor of Horticulture at Auburn University and served as the University Spokesperson for the Toomer’s Oaks Poisoning and as Head of the Remediation Task Force.