Irrigation Leader
Photo of Dr. Andrew Skibo and Kate Mohatt wading through water and applying chemicals to the water. Mountains in the background.
Innovator,  Interview

The Preemergence Perspective How Andrew Skibo Is Changing the Mindset on Weed Control

One of an irrigation district manager's main challenges is costeffectively ridding his or her systems of aquatic weeds in order to ensure a smooth flow of water. Traditionally, irrigation districts have injected chemicals directly into the irrigation water to control weeds. Alligare, a renowned vegetation management solutions company, has been working successfully with preemergent weed control programs for the last several years. Preemergent weed control, while not a new strategy in the world of terrestrial weed management, is relatively new in the world of aquatics. Its goal is to prevent aquatic weeds from growing in irrigation ditches in the first place, thus eliminating or greatly reducing the need for in-season treatments. Forward-thinking irrigation districts across the United States have been using Alligare’s preemergence solutions for several years with great success.

Irrigation Leader writer Parker Kenyon spoke with Andrew Z. Skibo, PhD, a technical support specialist in Alligare's aquatics division, about the preemergent weed control program, current challenges in aquatic weed management, and Alligare’s vision for the future of the technology.

Parker Kenyon: Would you please tell us about your professional background?

Andrew Skibo: I have been working in agriculture for the past 16 years. I have a background in herbicide mode of action, the environmental fate of pesticides, and invasive species control. I have been working in aquatics, predominantly the irrigation market segment, for almost a decade. My focus has been primarily on the western United States. I was previously based in Colorado, where I led the western research and development focus for another company. I joined Alligare earlier this year.

Parker Kenyon: Please give us some information about your educational background.

Andrew Skibo: I have a dual degree, a bachelor of science in plant and animal science, from the University of Delaware, with a focus on production agriculture. I continued my education and obtained a PhD in plant and soil science, also from the University of Delaware. My focus was on weed science, weed biology, weed population genetics, environmental chemistry fate, and so on. On paper, I am a classically trained weed biologist. By trade, I am an aquatic plant biologist specializing in invasive species control and eradication.

Parker Kenyon: Would you please tell us about the services that Alligare provides?

Andrew Skibo: Many folks in the irrigation world know Alligare as the Magnacide H Herbicide company, but in the niche industrial vegetation management market, we have the most comprehensive portfolio in the industry. We provide solutions to the range and pasture, right-of-way, railroad, forestry, and aquatics markets. While aquatics is a large piece of our portfolio, we have a great team of specialists supporting the broad portfolio of Alligarebranded active ingredients in the industry.

I work in riparian and aquatic areas—basically, from the ditch bank down and then across the water. I would say that approximately 60–70 percent of what I do is related directly to the irrigation market, while most of the rest of my work is on state and federal contracts working with invasive and nuisance species control. Alligare provides solutions to managers working in ponds, lakes and rivers, and irrigation canals, and we provide support to managers of drinking water reservoirs. In short, we go wherever we are needed.

Parker Kenyon: Please tell us about the work that you and Alligare are doing with preemergence technology.

Andrew Skibo: When we’re talking about in-season, in-water treatment options, there are currently only a few active molecules available to the irrigation system manager. Typically, when you ask folks how you control weeds in an irrigation ditch, the thought process has been, “We put something in the water.” Weeds are controlled in season. With this approach, there are only a few available means of control that can be used in an irrigation ditch during the season when you are delivering water to clients. For several reasons, some of those may not be suitable to a specific system, whether because of regulatory concerns or the end use of the water. So, when approaching a new water conveyance system, we always refer to our “toolbox” in the irrigation market. We start with, “What do we have available to us today?” When I talk to an irrigation district manager, the first thing we want to know is where the water is going; what it is being used for; what the dominant cropping systems are; and, ultimately, what the goals for the system are. Then we can start figuring out which tools are suitable.

If we were ever to lose one of these tools because of resistance or regulation, we would really have our hands tied. So we broadened our perspective and asked, “What if we approached weed control in irrigation canals from a slightly different perspective and made the applications in the fall or the spring of the year? What could we do there?” Your prospective toolbox becomes much larger with this approach. You now have a larger number of modes of action that could be used to provide long-term, in-season aquatic control. We approached the market with this in mind, and over the past few seasons, we have really started to build a solid operational program.

The programs that we are continuing to develop could be applied anywhere from several weeks following water shutdown—say mid-October—to up to 30 days prior to canal recharge the following spring. That really expands the window of application in what is traditionally downtime, a maintenance and recovery period after the madness of the water season. Even with traditional off-season maintenance programs, such as reshaping, burning, desilting, and lining, there is plenty of time to put these programs in place. Provided that the proper specifications regarding timing, method, and chemistries used are followed, we usually see season-long weed control. Once the system has been recharged the following season, the only thing left to do is to clean up hot spots where you have breakthroughs and manage algae growth. Unfortunately, there are no preemergent programs for algae, but that can be done cost effectively through traditional aquatic chemistries.

The concept of preemergent aquatic weed control really does turn traditional weed management on its head because you are doing it before water is ever in the ditch. While this approach is relatively new in the aquatics market, our colleagues in traditional row-crop agriculture have been doing it this way for over 50 years. Where preemergent programs have been trialed and adopted, they have worked well.

Parker Kenyon: What are some of the challenges of the preemergence program?

Andrew Skibo: From a technical background, some of my concerns are making sure that we have combined modes of action, because we are not just seeing weed pressure from in-season aquatic weed species. For a lot of ditches that may flood late, particularly those in the Great Plains and Rocky Mountain regions where people may not charge their systems until mid- or late May, we are seeing control of a lot of the spring annual terrestrial weeds. These are typically managed with a preflood burndown application of glyphosate with varying levels of success. We know that a lot of these winter annual species have resistance issues, particularly to glyphosate and to some of the other more traditional chemistries. Thus, when we have combined modes of action, we are following best management practices to gain control of those resistant spring annuals with these chemistries.

One of the biggest challenges is changing the mindset of the irrigation market itself, which is often, “We have always done it this way.” We at Alligare want to challenge that. If you keep doing what you have always done, then you are going to get what you’ve always got. Although there are traditional chemistries available, we have started gaining traction with forward-thinking managers who are aiming to improve their program. These managers understand who we are at Alligare and what we have to offer.

A bigger-picture challenge that we face almost daily is the perception that Alligare is a generic company. I like to challenge customers and competitors alike by saying that in the world of aquatics, there really is no such thing as a generic. There is currently one molecule that is on patent. Everything else is postpatent. What most managers are purchasing is simply a product in a jug. Anyone can put a product in a jug and sell it. Rather than trying to sell convoluted rebate programs that may end up costing you more money or offering limited guarantees, what we are really selling is the technical support and the information on how to use these programs—where they work, where they don’t work, and what caveats to keep in mind while using them.

We are also selling peace of mind with the guarantee that if you use our products and follow our recommended programs, we will be there to back you up if a problem arises. What matters more than knowing that your success is our number-one priority, that we will be there at 2:00 a.m. on a Saturday to assist you in any way you need, and that we will ensure you get to keep more of your hard-earned dollars? I would claim that Alligare has the best technical support available in the industry as well as quality products and the most honest and transparent pricing you will find anywhere.

Parker Kenyon: What message do you have for our readership?

Andrew Skibo: I hope that it doesn’t come across as a cliché, but I would say, “You are not alone.” This information is out there, and there are people who want to help you make informed decisions. I came to this market from a nonsales background: I came from a pure research and development background, where my job was to translate data into a form in which it would be useful in the field to get a job done in a safe and economical fashion. My entire career has been focused on the translation of information to the end user.

When I talk to clients, I always try to preface my advice to them by saying that, yes, I work for Alligare, but I hope I earn the reputation of being a relatively pure source of information, a resource. Here is what is available to you, and here are the relative benefits, downsides, and costs of all these programs. I will always strive to help you get to a point where you can make an informed decision. At the end of the day, it is the irrigation manager whose job is on the line and ultimately, he or she is the one who must make the decisions necessary to supply water to the clients. I am available 24/7, but it is the people in the field who are getting the job done, and I am just trying to support them.

Parker Kenyon: Is there anything that you would like to add?

Andrew Skibo: When you look at the aquatics market in comparison to the global pesticide market, there are no new actives coming down the pipeline. What is available to us in the irrigation market is just a small subset of what is already a small toolbox. We really do need to steward these products as best we can and use our best management practices so that we do not risk losing any of these tools. To that end, Alligare is launching Alligare University, a series of training seminars designed to bring up-to-date information on aquatic and riparian vegetation management to irrigation district managers and ditch riders. Stay tuned for more details coming soon! Finally, I would like to thank Irrigation Leader for the opportunity to discuss this important topic.

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