RESEARCHING MAINTENANCE

Bored to death What are the options for controlling tree borers now that lindane and chlorpyrifos are gone? - Missouri

Actually, several products currently on the market are labeled for borers and are used in much the same way as lindane. That is, applications to tree trunks and branches in spring and summer catch newly hatched larvae before they can bore into the plant's tissues beyond the reach of chemical controls. Until recently, the most frequent recommendation for preventive treatments was chlorpyrifos (Dow's Dursban and other brands). With the loss of chlorpyrifos, professionals are using permethrin. FMC, Prentiss, Bonide and Micro Flo all have products containing permethrin.

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Another option for preventive treatments is imidacloprid. Bayer recently received registration to allow soil drench and soil-injection treatments with Merit for borers (and other pests), but not all imidacloprid-containing brands are registered for borers. According to Dr. Douglas Spilker, turf and ornamental product manager with Bayer, roots take up the chemical, and concentrations in the plant gradually rise to a level that provides control. The reason Bayer recommends this as a preventive rather than curative treatment is because it takes several weeks for adequate uptake to occur. Also, according to Spilker, concentrations of the chemical don't always reach high enough levels to entirely control heavy, pre-existing infestations. By contrast, effective prevention requires relatively low levels of active ingredient.

Trunk injections are the most effective and rapid way to treat an existing infestation, though it is not always possible to kill every borer present, particularly when they are larger and nearing maturity. Injection products containing imidacloprid are effective against coleopteran (beetle) borers, which include the round-headed and flat-headed borers. Lepidopteran borers, such as the ash-lilac borer, require different active ingredients.

Micro-injections are becoming a common method for dealing with borers according to Marty Shaw, a tree injection specialist with TIPCO, Knoxville, Tenn. "The micro-injection treatment uses the tree's own natural transport system to move pesticides throughout the [tree's] living tissues, making the entire tree toxic not only to adult borers laying eggs, but also to the larvae that are actually causing damage," states Shaw.

It's difficult to overstate the importance of good cultural management for preventing (and treating) borers. Healthy trees are capable of repelling many borer attacks by initiating heavy sap flow at attack sites. Stressed trees, by contrast, cannot mount much of a defense, which apparently is why borers attack them preferentially. By giving infested trees help in the form of supplemental water and fertility, and correcting other existing problems (compacted soil, for example), infested trees often will recover if you take appropriate control measures in the meantime.

Shaw uses his "one-third" rule as a prognosis tool. If a tree has lost no more than a third of its canopy, it probably will survive assuming proper steps are taken. However, infested trees often succumb to secondary problems, such as fungal pathogens, resulting in a "downward spiral." If a tree is too far gone, according to Shaw, eliminating the borers may not be enough to save it.

Leaky engines On some of my older equipment's engines, there's a lot of oil seeping through the head gaskets. Can I just tighten the bolts to put more pressure on the gaskets and stop the leaks instead of replacing the gaskets altogether? It seems like this would help, but it would mean exceeding the manufacturer bolt torque specs. - via the internet

Head gaskets, over time, may leak. According to Robert Sokol, editor of the Clymer Powersport Blue Book, the theory is that when the engine was assembled, the head gasket was maybe 6/64 of an inch thick. Over the course of time, along with wear and tear, the head gasket was compressed, and might now be perhaps 5/64 of an inch.

This little gap is where the oil will escape. Can you just tighten the head bolts and expect the oil to stop? Perhaps. Sokol suggests that, about 75 percent of the time, you can just tighten the head bolts to the factory-recommended torque to stop the oil leak. Remember, on older automobiles, it once was a common practice to re-torque the head bolts. However, under no circumstances should you ever surpass the recommended factory specification for torque. The bolts, threads and component parts are all designed for a specific torque. Going beyond this torque could cause broken bolts, stripped threads and warped parts, according to Sokol.

If re-torqueing the head bolts does not stop the oil seepage, then you will have to decide whether the seepage is enough to warrant replacement of the head gasket, a more expensive repair.

Misinformation and regulatory stranglehold - is this where our lawmaking process is headed? All green-industry professionals should ask this question because it directly affects us. New laws and regulations are constantly enacted that limit our ability to practice our profession, and schools have become the most hotly debated battleground. Over the past few years, at least 23 localities have restricted or attempted to restrict the use of pesticides on school property. Here are two examples.

Last year, the Los Angeles School District enacted a policy prohibiting the use of pesticides on school grounds. The policy was enacted with little attention to feasibility studies to determine the consequences. The result has been disastrous. Weeds are overgrowing the playgrounds and athletic fields. Without the use of herbicides, the grounds crews have tried implementing blowtorches and scraping blades attached to utility carts to rid weeds. Neither of these ideas worked, and crews can't use hoes and shovels to dig out weeds because they damage asphalt. String trimmers are employed, but are expensive - the crews use more than 800 feet of trimmer line per school. The financial estimate of chemical-free weed control was so grossly underestimated by the school district that its original budget has more than doubled to $1.35 million annually.

The ban also has caused a backlash among grounds-care employees who feel like they are being punished when they have to shovel weeds in 100ø F heat. And one principal commented that his school looks like part of a slum.

On the federal level, proposed legislation would ban pesticide use on school property nationwide. The School Environmental Protection Act (SEPA), introduced in October 1999 by Senator Torricelli, D-NJ, suggests the establishment of a 12-member board in every school district to oversee the process of eliminating pesticide use on school property. The 12-member panel would consist of parents, education administrators, integrated pest management (IPM) specialists and environmental advocacy groups, with no representative from the applicators industry. All decisions concerning the integration of IPM and pesticide use in schools would be decided by this board. Whether the bill will pass is unclear at this point.

As these examples show, onerous regulations can occur at all levels of government. Be aware of regulatory initiatives in your area. Voice your side of the story. These regulations will continue to pop up throughout the country. They offer a chance for chemical applicators to educate the public and help bring some common sense back to environmental regulations.

Have you ever marveled at the dark-green color of a healthy sward? Nutrition has something to do with it, but the result is primarily due to genetics. The American public prefers dark-green turfgrass and breeders know this. They are constantly improving varieties to produce a darker-green color. Color is also important to breeders because they must consider it when blending varieties or mixing species. But turfgrass color evaluations are performed by individuals and, therefore, are limited by subjective perception. Even experienced evaluators can perceive color differently on different days.

Drs. Peter Landschoot and Charles Mancino at Pennsylvania State University recently tested a new colorimeter to evaluate its effectiveness in determining color differences in bentgrass. The colorimeter measures several parameters when placed directly over turf. It blocks all external light from the measured area. A lamp inside the unit emits a brief flash of light. The light reflected back from the turfgrass is then analyzed by the colorimeter to determine hue, lightness and other parameters. Hue is the evaluation of color with respect to red, orange, yellow, green, blue or any mix of them whereas lightness is judged by how well a substance reflects light.

The researchers found that visual color assessments by the most experienced evaluators were relatively consistent while the least experienced evaluators visually assessed color differently. They found that all of the evaluators ranked the cultivars the same from light to dark, but their ratings of darkness (on a scale from 1 to 9) of each cultivar differed.

The researchers' work also indicated that hue measured by the colorimeter was consistently correlated with the visual lightness (or darkness) assessment made by the evaluators. This means it is possible to use the equipment to rank turfgrass darkness using the hue readings in a way that should match traditional color evaluations. The hue measured by the colorimeter may not be as sensitive to color differences as the evaluators' visual assessment. It does, though, provide consistent measurements no matter who uses it.

The researchers agree that the greatest use of the colorimeter may be in determining like-colored cultivars for use in blends. They suggest that cultivars with hue, lightness and other measurements that are similar are likely prospects for blending. They also are careful to note that these tests were conducted only with bentgrass, and results could differ when other species are evaluated.

The colorimeter may assist breeders in cultivar selection for blending. While visual evaluations will continue to be the common method for color analysis in trials and breeding, they still are limited by the experience of the evaluator. Because visual perceptions differ, colorimeters may allow for more objective and consistent evaluations of turfgrass.

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