Corn+Soybean Digest
Integrated Pest Management proponents suggest that traitresistant western corn rootworm along with pyrethroid resistant soybean aphids and herbicide resistant waterhemp could have been slowed or prevented had growers followed IPM strategies Bruce Potter IPM specialist Univ of MN notes that while IPM is not easy managing resistant pests is neither easy nor inexpensive

Integrated Pest Management proponents suggest that trait-resistant western corn rootworm, along with pyrethroid resistant soybean aphids and herbicide resistant waterhemp, could have been slowed or prevented had growers followed IPM strategies. Bruce Potter, IPM specialist, Univ. of MN, notes that while IPM is not easy, managing resistant pests is neither easy nor inexpensive.

Is IPM dead or different?

Think Different The idea of scouting for economic thresholds before treating seems less appreciated than any time in IPMs 56-year history. Applying fungicides and insecticides in a single pass as preventatives runs counter to traditional IPM; however Key Co-op agronomist Jason DeBruin suggests that such practices are a matter of logistics. While University of Minnesota IPM specialist Bruce Potter sees traits, seed treatments and applications of insecticides and fungicides as valuable components of IPM if efficacious, their blanket application is not IPM. It's not likely that current economics will force a rebirth of IPM, unless farmers learn to evaluate both the need and the proposed solution for themselves.

When introduced in 1959, Integrated Pest Management (IPM) was hailed as the answer to environmental, worker safety and grower-cost concerns with over-use of crop protection chemicals. With widespread use of traits, seed treatments, fungicide and insecticide treatments designed to prevent potential pest problems, IPM would appear to be dead. Certainly the idea of scouting for economic thresholds before treating seems less appreciated than any time in IPMs 56-year history.

Iowa farmer Blake Crawford gives credit for the change to modern pest control. At the same time, he sees a renewed need for at least some IPM principles.

"I think we've gotten away from IPM," he says. "For my customers, integrated traits in hybrids are the No. 1 option as they are easy to use and affordable versus scouting and using IPM, and give good control of most problem pests."

New rootworm issue

That said, Crawford, who with his brother Justin and father Randy farm and manage a DuPont Pioneer seed dealership, is keeping options open as his pest paradigm shifts. In 2015, post-tassel winds knocked down first-year corn in their area. Field scouting with sticky traps and root evaluation identified all-time high numbers of northern corn rootworm as the culprit. Until now, the southwest Iowa growers and their customers have generally relied on rotation with soybeans to control corn rootworm, leaving trait hybrids for corn-on-corn. Extended diapause corn rootworm is changing that, just as glyphosate resistance changed their weed control.

"On the weed side, we've gone to more mixed modes of action on soybeans than in the past, including using a residual. We also get out and scout more and earlier," he says. "With the appearance of extended diapause rootworm, we decided to put SmartBoxes on our planters. Alone or with stacked traits, they offer another mode of action. While we won't scout every acre, we will do more scouting."


Download this article in .PDF format
This file type includes high resolution graphics and schematics when applicable.

 

Today’s IPM different?

Jason DeBruin, agronomist, Key Co-op, New Sharon, Iowa, argues that today's emphasis on multiple modes of action and switching modes of action are a modern version of IPM. "We call it resistance management, not IPM. However, when guys ask why a product or trait isn't working, we respond with ways to fight it, and that is IPM," says DeBruin. "It is a conversation that is happening more often."

DeBruin admits that applying fungicides and insecticides in a single pass as preventatives runs counter to traditional IPM; however he suggests that such practices are a matter of logistics. Rather than count on scouting, thresholds and in-sufficient windows for application, products are used.

Bruce Potter, IPM specialist, University of Minnesota, claims a different definition for IPM. While he sees traits, seed treatments and applications of insecticides and fungicides as valuable components of IPM if efficacious, their blanket application is not IPM.


Download this article in .PDF format
This file type includes high resolution graphics and schematics when applicable.

"Focusing on individual management components is where we get into trouble," he says. "From my perspective, IPM means minimizing unnecessary input expenses while maintaining yields and using multiple pest control tactics to preserve flexibility in future pest management. It's a long-term management, whole farm philosophy, and I know it isn't easy, but neither is managing resistant weeds and pests. That can be expensive to boot."

Research lacking

Potter notes that public and private funding needed to move interdisciplinary research forward has been lacking. At the same time, while short and long-term economics and long-term production risks may favor IPM, the risk-averse nature of most farmers makes it easy for them to buy into "one size fits all" pest management.

Curt Burns is all too familiar with risk-averse farmers and what he sees as a crop protection industry more concerned with its bottom line than that of its customers. As a Minnesota farmer and a crop consultant, he practices and promotes IPM. While he credits the industry for the products it has developed, the drive for market share at any cost frustrates him.

"The farmers who work with me understand IPM, scouting and when to initiate treatment," says Burns. "As we plan the budget for the banker, the grower knows he can't justify the extra $10 to $20 per acre for seed treatment on soybeans. Later when he hears company claims that a seed treatment will make him an extra two to three bushels per acre, he decides to do it in the heat of the moment. Then he has spent more than he needed to or budgeted."

Burns acknowledges that for some farmers and some fields, a seed treatment may pay. However, he also points out that no independent research suggests that a blanket approach to soybean seed treatment does pay. 

"Seek independent research that tells the whole story with replicated, random block trials that are statistically valid," advises Burns.

 

Blanket control is bad

Jonathan Lundgren, entomologist, USDA-ARS, Brookings, S.D., has long argued against blanket approaches to pest management. Part of that is the systemic failure that has occurred in the past. Part of it is the reality that blanket approaches are likely to kill more beneficials than pests, lowering or eliminating natural controls of surviving pests. Of immediate benefit to farmers facing flat or negative projections is cost savings.

"In the 1950s, 60s and 70s, we saw the collapse of prophylactic pest management as pests became resistant and there were environmental and human health costs," explains Lundgren. "We are starting to see similar patterns today. As margins grow thin, those farmers who abandon neonicotinoid seed treatments are saving money. Those abandoning Bt hybrids are saving money. Public sector research shows these products may not be necessary to use every year. Unless farmers clearly see economic levels of pests annually in a field, the pest pressure simply doesn't justify the use of these tools."

While he continues as a USDA-ARS researcher, Lundgren and his wife Jenna have started Blue Dasher Farm in Deuel County to practice what he preaches. Their goal is to show farmers how to eliminate much chemical use.


Download this article in .PDF format
This file type includes high resolution graphics and schematics when applicable.

"We are pro-farmer and pro-natural resources, not anti-pesticide or anti-GMO," says Lundgren. "We want to show how if you do things a little differently, you don't need these costly chemistries."

Ask more questions

Burns, Potter and Lundgren all emphasize the potential for current economics to force a rebirth of IPM. However, Burns points out that it's not likely unless farmers learn to evaluate both the need and the proposed solution for themselves. He suggests looking at the questions before you accept the answers.

"Ask if there were replications?" says Burns. "Where were the sites? Was there testing against other products? What varieties or hybrids were tested and what level of resistance to the pest did they have? What was the weather? What about soil types? You need as much hands-on statistics as possible."

Potter points out that Minnesota farmers (and others) are paying the price for "easy" pest management. He cites failed varietal resistance to soybean cyst nematodes, resistant weeds, Bt-RW resistant western corn rootworm populations, insecticide resistant two-spotted spider mites and, most recently, synthetic pyrethroid resistant soybean aphid populations as the inevitable results. Unfortunately, as resistance mounts, control options with or without IPM decrease, and crop protection costs rise.

"Rumors of IPM's death may be greatly exaggerated," quips Potter. "That said, it does appear to have been in a state of diapause. I don't believe that insects, weeds, plant disease and economics will allow IPM to die. Some of the human components in agriculture, however, will continue to see some aspects of IPM inconvenient."

Hide comments

Comments

  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.
Publish