Landscape & Irrigation

26 July/August 2016 Landscape and Irrigation www.landscapeirrigation.com but, because of the age of that research, a lot of folks just don't know about it. So we tried to put it together in a more readable form so they could find it more rapidly. Bernick: As far as some of the data gaps that are still out there, it would relate to some of the comparative assessments of the different devices and how they may or may not cause adverse affects over longer periods of time, with repeated annual injections or injections performed every few years — those longer-term studies seem to be missing. I think the kind of things that are hard to study in a replicated trial are "what are the long-term impacts if these treatments are done correctly — using some of the practices laid out in the BMP?" and then, "what are the long- term impacts to the tree if done incorrectly?" That was one of the challenges putting the BMP together — taking information of the industry that there may not have been university or replicated research on, and then coming to a consensus on those industry recommendations for which we may not have a fully vetted research project. We just didn't have published research to fall back on, so we had to rely on industry experience for many of these recommendations. Smiley: That's right, a lot of BMPs — whether this one or others — are based on what is done in the field, not necessarily what is known in the research. I think smart and opportunistic researchers can look at these BMPs and probably find at least a dozen opportunities for further research studies. Certainly, we do that here at the Bartlett Lab, where we are working on these BMPs we can see the voids. Sometimes it's a quick experiment and sometimes it's a longer experiment, but it can guide future research to answer some of these questions. Q: What were some of the challenges to putting this guide together? Bernick: Right off the bat, just defining some of the terms that were being used differently. For example, "injection" versus "infusion" and how they were being used differently in the industry. Coming to a consensus is what I like about the BMP, including the glossary of terms in the back. So as we are out training practitioners we can be using these terms to create a common language. Another challenge out of the gate was knowing that we wanted this document to stand the test of time — to not have to go back and revise it every year. So a challenge was "do we want to include the common active ingredients and trade names?" and while we felt that would be a benefit, it was probably outside what we were trying to accomplish with the BMP. It's probably not what a BMP is intended to have, but it would be good to have that out there. We felt that got too into the commercial piece, and saw challenges from the device manufacturers and wanted to steer clear of that. Smiley: Certainly there were challenges out there from the different injection products, all the different materials, and a lot of people doing the treatments in different ways. I think Shawn did a really god job of overcoming all of those. Q: How often do documents like this get updated? Smiley: It varies a bit based on the origin of the BMP. Most of our BMPs are based on the ANSI 300 standards, and there is a schedule for updating the ANSI A300s that is a five-year schedule. Once a new standard comes out, we review that standard with an eye on the BMP and then revise that BMP. With ones like Tree Injection, where we don't start with an ANSI standard, we would try to stick pretty close to that five-year schedule, but it is not as rigorous. I think we will take a look to see if anything has changed that will substantially alter the recommendations in the BMP. Not every BMP needs to be updated every year, but certainly they need to be looked at every five years. Q: Why do you think there is controversy surrounding tree injection wounding that we don't see in other practices, such as pruning? Smiley: I think some of that comes from the difference in anatomy, like if you are taking a branch and not cutting the trunk, we've got a pretty good natural defense system going on there. But we also have a pretty good defense system in the trunk and root flare — one of the reasons we like root flare injections more than the trunk injections is that most trees tend to be pretty good compartmentalizers in that root flare area. I think the main reason [it can be controversial] is that it is seen as an option in many people's minds. And we do mention that if you can spray or soil apply a treatment that you may be better off. We try to reserve tree injections for those cases where we just can't get the efficacy with spray or soil treatments. Bernick: I think, for me, it comes down to the techniques, whether pruning or drilling, if you are able to do them properly and well timed [they are beneficial]. We know with both of them if we do them too often or do them poorly they can be harmful. TREE CARE PHOTO PROVIDED BY RAINBOW TREECARE SCIENTIFIC ADVANCEMENTS

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