Clarke McGrath

Clarke McGrath currently serves as the On-Farm Research and Extension Coordinator.

Prior to joining Iowa State University, McGrath spent nearly a decade as a retail agronomist and manager in the GROWMARK system, earning three M.A.R.C. of Excellence Awards, five Annual Sales Program Awards, six Iowa Top Gun Awards, and three Regional Top Gun Awards.

McGrath is a Certified Crop Adviser (Iowa and National) and a retired/honorary firefighter of the Harlan Fire Department where he was a Heartland Heroes nominee and was awarded the American Red Cross Certificate for Extraordinary Personal Action, the organization's top award for saving a life. He also serves as a peer advisor/mentor for fellow accident survivors recovering from traumatic injuries. He was raised on farms in Union County, Iowa and Dixon County, Nebraska.

Clarke McGrath photo
September 14, 2017 12:31 PM

It’s always difficult to forecast weather, but if dry field conditions persist, potential for combine and field fires this fall could be a problem. All it takes is a single high-temperature source in the engine area, or an overheated bearing to ignite dry plant material.

During harvest...

Crop Production
June 26, 2017 12:57 PM

We are now past the Summer Solstice, which means daylight hours will be getting shorter and we will starting seeing more flowers on soybean plants in fields, which has triggered questions about when we have to stop using dicamba on Xtend beans.

There isn’t really a true “cutoff date” for...

Crop Production
April 30, 2017 11:59 AM

After a decent start to the planting season, cold and wet weather has put the brakes on field work for a while. As we look ahead into next week, or whenever it starts to dry out enough to get back in the field, growers are figuring on being able to spray a day or two before it is dry enough to...

Crop Production
September 30, 2016 9:57 AM

Seems like I have written an article on stalk rot about every year for the last five or six seasons. Luckily, for the most part, the last few years it was a “heads up” about a relatively small amount of fields that were having lodging issues. However, this year it sure seems like stalk integrity...

Plant Diseases
September 22, 2016 12:22 PM

From a non-farm citizen perspective, safety on the roads is imperative. We have to be aware that during harvest and fall field work season, there will be a lot of large and slow moving equipment on the roads. There will also be a lot of grain trucks on the roads, and it is a tough job to drive...

Crop Production
September 21, 2016 10:22 AM

Safety is always a priority for farmers at harvest, but this year may push us harder than most. If our current wet weather pattern continues into the fall, it could be a muddy, difficult 2016 harvest season.

Crop Production, Equipment and Machinery
September 20, 2016 10:16 AM

Sept. 18-24 is National Farm Safety and Health Week and Iowa Farm Safety and Health Week. Clarke McGrath, on-farm research and extension coordinator for the Iowa Soybean Research Center and extension agronomist at...

Crop Production, Grain Handling and Storage
June 17, 2016 9:27 AM

There aren’t great answers to contend with the root cause (pun intended) of the uneven corn this season. The unusual weather conditions that started last winter and extended into this spring, and long periods of stress magnify small differences within fields and improves the odds of seedling...

Crop Production
June 16, 2016 5:04 PM

I've been getting a lot of calls about uneven corn. Uneven corn can be caused by many factors, and there are usually multiple variables in play. Since a lot of folks have asked, here are some reasons I am seeing uneven spots in fields around west central and southwest Iowa.

Crop Production
June 13, 2016 5:31 PM

Check weed sizes vs. herbicide rates so you can maximize herbicide effectiveness. I am getting calls on some pretty sizeable weeds in fields, especially ragweed and waterhemp. Some of the ragweed (and marestail in some no-till and min-till fields) is already beyond being able to consistently...

June 7, 2016 10:22 AM

Most of the corn is around V3 to V6, with some of the replant corn popping up with the heat. I think (hope) I saw my last replanted corn being put in yesterday, some wet spots that had dried out on the edges of some bottom fields.

Spraying corn...

Crop Production
May 6, 2016 4:08 PM

I've been getting a lot of questions about needing additional N for corn; growers are torn between putting some UAN in with herbicides vs. spreading urea. I’d caution them against using UAN as a carrier on emerged corn if they are applying herbicides. Yes, there are a few products that allow...

Crop Production, Soil Fertility
May 3, 2016 3:12 PM

Replanting is something we hope we don’t have to do a lot of, but if we do, there are some good resources to use to help make those decisions.

Stand assessment and replant decisions are often (OK, almost always) agonizing. It is hard to leave a stand that is below...

Crop Production
April 25, 2016 11:52 AM

Corn typically requires 90 to 120 Growing Degree Days (GDD) from planting to emergence. Of course this GDD range assumes adequate soil moisture and varies with planting depth, tillage system and residue cover. As a rule of thumb, if 120 GDD have accumulated since planting and seedlings haven’t...

Crop Production
April 7, 2016 8:58 PM

I've had a lot of questions/discussions this week about planting corn. I had some growers get started Monday, some others were going to start towards the middle or tail end of this week, a few were going to wait until Monday, and a few were undecided. When to start planting was probably...

Crop Production
March 25, 2016 6:10 PM

Meaghan and Bob’s blog posts on weeds, and seeing a floater spraying yellow herbicide in 30 mph winds on Monday, reminded me to do an update on our newest problem child in the weeds world, Palmer amaranth. While we hoped that the few infestations scattered across Iowa could be contained,...

October 20, 2015 2:45 PM

By Clarke McGrath and Mark Hanna

It’s always difficult to forecast weather, but if dry field conditions persist, the potential for combine and field fires this fall will continue to be a problem. There have already been dozens of significant field fires around the state,...

Crop Production
October 16, 2015 11:02 AM

By: Clarke McGrath

It’s NH3 season, so here are some safety reminders from a guy who has seen how badly NH3 can injure people, first-hand. We work around it so much that sometimes we forget how caustic and dangerous it is.

Crop Production
October 9, 2015 4:44 PM

By: Clarke McGrath

In running plots and talking with growers the last week or so, the shift to more “fall-like” temperatures has people thinking, “Maybe I can run some fall NH3 while (if) I am held up waiting on trucks, grain drying, or other typical fall delays.”

Having been...

Soils, Soil Fertility, Soil Management
October 7, 2015 4:24 PM

By: Clarke McGrath

Stalk rot issues have only gotten worse in recent weeks; in some cases, a lot worse. Stalk rot and resultant standability challenges have reportedly been issues across much of the state, and are not hard to find in most of southwest and west central Iowa.


Crop Production, Plant Diseases