Begin Scouting for Black Cutworm in Corn -2022

May 16, 2022

By Ashley Dean and Erin Hodgson

Black cutworm (BCW) is a migratory pest that arrives in Iowa with spring storms each year. It is sporadic and unpredictable, making it essential to scout to determine whether BCW larvae are present in a field and management is required. Because BCW is sporadic, it is usually not economical to use preventative insecticide applications; however, rescue treatments can be very effective if scouting reveals larvae are present. Even though cool, wet conditions have slowed planting progress throughout the state, BCW development is on track with previous years.

It may be even more important to scout this year, because delayed planting may result in the “perfect storm” for BCW injury: small corn plants (less than V5) in the field at the time larvae are large enough to cut corn plants. Moth flights into Iowa will continue throughout the month, so prolonged feeding may occur on young corn plants. Scouting for BCW larvae can be combined with early season stand assessments or scouting for other pests.

Predicting cutting dates

BCW moths lay eggs in and near crop fields, and larvae can feed on leaves or cut corn seedlings. Larvae must attain a certain size (4^th instar) to be large enough to cut corn plants and cutting can occur until plants reach the V5 stage. We can predict when BCW will reach the 4^th instar based on accumulating degree days and when a significant flight occurred. A significant flight occurs when eight or more BCW moths are captured over a two-night period in a pheromone trap. The Iowa Moth Trapping Network enlists the help of volunteers around the state to monitor BCW activity annually. You can keep up with the Iowa Moth Trapping Network with weekly updates posted to the ICM Blog.

Significant flights have occurred in most areas of the state. Counties that have reported significant flights include Taylor (April 13 and May 4), Buena Vista (April 22), Mills (April 22), Marshall (April 24), Mahaska (April 24 and May 4), Washington (April 24, April 29, and May 6), Lucas (April 29), Hamilton (May 2), Benton (May 5), and Polk (May 5).

Figure 1 shows the predicted cutting dates for BCW in each crop reporting district. These cutting dates are estimated by combining actual and historical GDD data. BCW trapping will continue throughout May, and any additional peak flights that occur will be included in our weekly ICM Blog updates.

Estimated black cutworm cutting dates for each Iowa crop reporting district based on initial peak flights in 2022, as of May 11. These are estimates of when cutting will begin, but additional large flights may indicate prolonged feeding by black cutworm larvae

Figure 1. Estimated black cutworm cutting dates for each Iowa crop reporting district based on initial peak flights in 2022, as of May 11. These are estimates of when cutting will begin, but additional large flights may indicate prolonged feeding by black cutworm larvae.

Source : iastate.edu

Video: The 15-Year Bet Behind Every New Variety!

Canada is trying to decide how much agricultural research capacity it can afford to lose. Brian Rossnagel believes the better question is whether the country can afford to rebuild it.

The longtime barley and oat breeder makes the case with a simple fact about his profession: the consequences of today’s decisions may not become visible for 10 or 15 years.

“Pick the right parents. That’s the biggest thing,” Rossnagel says. “If you pick the wrong parents, you’re not going to get anywhere—and you don’t know that until 10 years, 15 years later.”

That warning carries particular weight as Agriculture and Agri-Food Canada moves to reduce spending and streamline parts of its science operations. The department’s 2026–27 plan anticipates the loss of approximately 665 positions by 2028–29 and says some research will be reduced where capacity exists in academia or industry. AAFC says the changes will make its science operations more cost-effective over the long term.

For Canada’s seed industry, Rossnagel’s career illustrates what is at stake.

This fall, the retired University of Saskatchewan breeder will be inducted into the Canadian Agricultural Hall of Fame. During his 35-year career at the Crop Development Centre, he helped develop more than 100 barley and oat varieties, including CDC Austenson—one of Western Canada’s most widely grown feed barleys. His induction recognizes not only those varieties, but the collaboration and research system that made them possible.

Rossnagel is quick to emphasize that none of it was the work of one person.

“The first thing I thought about was all the other people who contributed to whatever success I and my program had over the years,” he says. “We know that it’s not an individual who does this. It’s a group—a team.”

That team extends well beyond the breeder whose name appears beside a variety. It includes technicians, pathologists, quality specialists, statisticians, regional testing sites, seed growers and industry partners. It also includes the breeders who came before and those who will carry the germplasm forward.

CDC Fraser barley, for example, moved through three breeding careers. Its parents came from Brian Harvey’s program. Rossnagel advanced the material after Harvey retired, and Aaron Beattie later guided it through registration and release.

That kind of handoff is normal in plant breeding. The person who makes the original cross may never see the resulting variety reach farmers.

It also explains why lost research capacity cannot simply be switched back on when budgets improve.

“If you shut it off, it’s very, very difficult—and particularly costly—to start it up again,” Rossnagel says. “If you have to start from scratch, it’s going to be at least 10 years before anybody notices whether you’re getting anything done or not.”

The concern is not simply how many experimental lines Canada can process. Modern equipment, statistical tools and genetic technologies allow today’s breeding programs to evaluate tens of thousands of lines—far more than Rossnagel could handle when he entered the field in the early 1970s.

But efficiency and automation do not generate every idea.

“If you pare back down, and instead of having six or seven individual scientists concentrating on wheat breeding, you go down and say three people could handle all this, well, that’s half the ideas gone,” he says. “Particularly if you happen to lose the three people who had the really neat and innovative ideas, boy, that’s a problem.”

It is a timely distinction for Canadian agriculture. Consolidating programs may preserve the volume of material moving through a system, at least initially. It may not preserve the diversity of thinking, regional knowledge or willingness to pursue unconventional crosses.

That regional knowledge matters because Canadian agriculture is not one uniform production environment. A variety suited to southern Alberta may face different disease, moisture and maturity pressures than one grown in Manitoba, Ontario or Atlantic Canada.

“Agriculture is applied biology,” Rossnagel says. “Biology, all around the Earth, moves from the poles to the equator. It does not move from Newfoundland to B.C. like politics do.”