The term has been around for decades, and it trips off our tongues as easily as “no-till management” and “cover crops.” Yet one of the challenges, even for those in search of a silver bullet in crop management, is the constant evolution of the term “IPM.”
Its meaning is rapidly evolving, and so are the ways of practising it in order to achieve better pest control at lower cost.
Part of the challenge, in fact, is how easily the terminology is tossed around. Are we all really talking about the same thing?
Definitions of the “pest” part of integrated pest management have had to stretch a lot in the past 10 to 15 years, and so have the tools we can use to keep on top of them. Seed traits and technologies have come to the fore, but there are new chemical innovations too, and even strategies such as precision agricultural systems and cover crops that focus on soil health.
Even among the experts, the definition can differ from one agency or individual to the next. The United States Environmental Protection Agency (U.S. EPA) states IPM is “an effective and environmentally sensitive approach to pest management that relies on a combination of common-sense practices.” It goes on to state that IPM is “best described as a continuum” where most growers identify their pests before spraying while a smaller group use “other methods.”
The University of California-Davis says IPM is based on scientific research, and that it focuses on “long-term prevention of pests or their damage by managing the ecosystem.” It goes on to note that IPM brings together approaches that are often grouped as biological, cultural, mechanical and physical, and chemical controls.
One of the more extensive resources on IPM is found on the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) website. The information and guidelines there reflect the province’s multi-faceted agri-food industry, with everything from fruits and vegetables to field crops, and from beneficial insects to weeds and diseases.
The evolution of IPM
Differing definitions are only part of the confusion surrounding IPM. There’s also the hard-to-escape fact that, as the tools of IPM evolve, so do our opportunities for using them, whether they are new traits, crop protection materials, or new trends in cultural practices.
The upshot is, wherever you look, there is no easy route for defining IPM, or for implementing its many facets.
That’s a concern for Tracey Baute. As the field crops entomologist with OMAFRA, she’s seen how the definitions have changed, along with perceptions of what constitutes IPM. In the wake of the current controversy surrounding the use of neonicotinoid-based seed treatments, she notes that growers are accused of not following IPM, under the misconception that chemical seed treatments cannot be part of an IPM strategy.
“Yet IPM is incorporated in almost everything farmers do, to some extent, so to say that they’re not doing it is not correct,” says Baute. “Chemical control, no matter what kind it is, is part of IPM. IPM isn’t going to suddenly save the world: we’ve been doing it all along, and in some cases, chemical control is still necessary.”
According to Baute, there are several messages that need to be reasserted in the farming community, including the four pillars of IPM — biological, cultural, mechanical (physical) and chemical. Each has its unique strengths and weaknesses, and all have their uses from one growing season to the next.
But it’s the idea that IPM is a holistic or total-package approach that can be most important.
“One step in the process, and it is one that I think everyone takes for granted and doesn’t realize is part of IPM, is taking the preventive measures — the crop rotation, or planting early or late, depending on what pest might be a problem, or proper fertility,” says Baute. “All of those aspects help improve the system in a bigger-picture approach, and I think they’re dismissed and growers don’t realize that they’re part of integrated pest management, where you’re doing these things likely for other reasons too, but in some aspects, it’s preventing the issue from the very beginning.”
Of course the other factor to keep in mind is that none of the four pillars of management in IPM are inexpensive, simple answers to the challenges that growers face. Beneficial insects are part of the biological controls, but balancing their introduction with existing cropping practices is both long term and complex. Adjusting planting dates can be a cultural control, yet weather patterns are often more of an influence on performance and yield. Different forms of tillage can provide physical control of weeds, yet there are always concerns about compaction and increased cost. And chemical controls are still a vital part of that holistic approach, sometimes for a pest that has passed its threshold, but sometimes too as a prophylactic measure.
“We’re constantly integrating pest management in what we do, so maybe it’s blurred a bit as to what is IPM now,” says Baute, noting that Bt corn has been one of the biggest advances in IPM, allowing less use of broad-spectrum foliar insecticides. “Some will argue it’s still an insecticide, it’s still a chemical control, but it’s almost more like a genetic control because it’s in the plant. But it’s our way of being able to successfully control a pest like corn borer that was a continuous problem that always needed to be controlled. And you’re reducing these insecticides, which lessens the impact on all other pollinators and predators that are present. I don’t think growers necessarily think of that as IPM anymore — it’s now just another crop to grow, but in all aspects, it is IPM.”
That’s also why it’s harder to establish a rigid definition of IPM. The changes in technology that have altered the agricultural landscape are myriad, but it’s true too that no two farms are the same. In the past 10 years especially, industry stakeholders have recognized that farmers, whether they live across the highway from each other or across the province, are farming on different soil types, or with different pest or weed species, tillage practices or crop rotations. There is no one plan that works for everyone.
“That’s why any decision on pest management usually comes down to economics, first and foremost,” says Baute, pointing to discussions about controlling grubs, as an example. “Homeowners can afford to try nematodes but that’s done at a totally different scale — those things have to be pampered and irrigated. But you take that same concept to a field scale and that’s $400 an acre, and farmers just can’t do that. Not every aspect of these possible control measures is going to be economical or feasible for a grower.”
The use of cover crops is another component. It’s been refloated as a saving grace for growers, and a way of improving soil health, boosting yields and encouraging a symbiotic relationship between certain cropping practices and beneficial insect species. But as Baute points out, there are also risks, including finding the right cover crop species to suit current cropping practices. What’s the best timing for planting? Is it easy to kill or easy to plant into?
“You could actually increase your insect pressure, depending on how you manage the cover crop, so it really comes down to modifying based on your needs and what your ultimate pest issues are,” says Baute. “The concept that by excluding chemical control, IPM will save us is not the case. IPM has to have chemical controls there as options, because with some pests, that is the control measure that we have to turn to if we want to produce a viable crop.”
Bigger and better?
One important consideration impacting the scope and definition of IPM is the physical size of so many farms. Technology like GPS systems or data transfer has provided more layers of information and greater scale. But renting or acquiring more land challenges the incorporation of any or all of the many facets of IPM, something Paul Sullivan has noticed in the past few years.
“Time is a premium for a lot of growers and it’s hard for them to step back and spend enough time assessing and evaluating, and they can get all kinds of information,” says Sullivan, an agronomist and independent certified crop adviser from Kinburn, Ont., just west of Ottawa. “That becomes an important part of making the best decision you can make. Some of the things that come into play for farmers aren’t properly evaluated a lot of times, just because in the race to get everything done and then start the season over again, there can be a lot of loose ends that don’t get looked after.”
Much of what can be learned in a season can also be forgotten in the time between harvest and the next planting season, and often a grower will default to the familiar. Farmers are tied to tradition, says Sullivan, and generally they don’t change things very quickly in spite of how fast things around them may be changing.
Partly that’s because farmers know there’s a price that will be paid if their strategies don’t work. Partly, too, it’s because they know better than anyone else how important it is to have realistic job lists that they can actually get done.
“We probably look at pest management on a fairly regular basis, but don’t recognize that we do,” Sullivan adds. “It’s a total-crop sort of scenario because as we look at some of the technology that continues to evolve and be used by farms, in some cases, some things work for growers and some don’t work at all.”
One example is fungicide in corn. Sullivan notes there’s a group of growers that consistently makes money putting fungicide on corn, and there’s a group that’s tried it and it didn’t work, and it won’t go back to it. But he believes success using fungicides on corn relates to what’s in the field: nutrient levels and the combination of conditions that boost yield might be related more to the genetics and not just the fungicide.
“It’s the same with fungicides, it’s the same with varieties, it’s the same with a lot of things,” says Sullivan.
Logic and common sense
Sometimes it’s best if a farmer tries to keep things uncomplicated and not overthink IPM with its many tools, layers and systems. Sullivan sides with Baute on the notion that some growers don’t realize that crop rotations are a part of IPM. Common sense and logical, basic crop production practices become the basis for the foundation of pest management. And that allows the crop to resist some of the things that could become a bigger issue.
“Keeping a field clean of weeds helps to eliminate cutworm moths from coming in,” Sullivan explains. “And good weed management with a burn-down in the spring, ahead of soybeans, reduces the risk of glyphosate-resistant Canada fleabane from becoming an issue.”
To Sullivan, that burn-down isn’t just a payback to the grower, it also sets the stage for IPM practices later in the year, and it builds on control measures that will be a benefit during the following season. At that point, the grower has a cleaner field that’s easier to control weeds in the subsequent wheat or corn crop.
Yet as much as the technology has added and enhanced IPM practices, Sullivan believes there’s more that advisers, agronomists and dealers can do to help smooth the way as IPM continues to evolve.
“As advisers to growers, we respect their experience, we respect their perspective, but in some cases, I don’t think we’re counselling farmers enough — we don’t try hard enough to help them understand what’s happening,” says Sullivan. “If they decide that that’s not something they’re going to do or that they are going to do, when in our assessment it doesn’t make sense to do it, it’s understanding the parameters that are there. And I think that as a support level for growers, CCAs and other advisory staff within the industry, we have to help growers understand their risk or the actions they’re taking and how those become important considerations.”
Some growers, Sullivan adds, can take the concept of IPM and move it ahead faster within their operations. Often-times, these are the innovators and early adapters, and they’re usually the site of more attention and resources — as a means of spreading the word and sharing ideas. In addition, there are growers who are as comfortable purchasing new equipment as they are in fielding advice via social media from Dave Hooker or Peter Sikkema at University of Guelph’s Ridgetown Campus, or from Bob Neilson at Purdue University. They can incorporate data points from their yield maps and pinpoint fertility issues, and mesh them with weed, insect or disease challenges.
“It’s not that those guys didn’t exist in the past — they did,” says Sullivan. “But we have a sector of growers that is more tech savvy, who have the ability to sort through and apply some of that technology better than a generation ago.”
This article first appeared in the September 2015 issue of the Corn Guide
For more information on definitions and the parameters affected by integrated pest management (IPM) guidelines, check the following websites: