Bob Hartzler

Dr. Bob Hartzler is a professor of agronomy and an extension weed specialist. He conducts research on weed biology and how it impacts the efficacy of weed management programs in corn and soybean. Dr. Hartzler also teaches undergraduate classes in weed science and weed identification.

Bob Hartzler image
March 12, 2017 12:52 PM

Since I inducted the FeXapan advertisement into the Herbicide Ad Hall of Shame for proclaiming to be the answer to resistance, I feel obligated to do the same with TeeJet's recent ad in Wallaces Farmer.  Proper nozzle selection is critical for:  1) minimizing off target...

Herbicide Resistance
March 9, 2017 11:33 AM

ISU's student newspaper recently published a story on Dr. Ada Hayden, the first woman to earn a Ph.D. from ISU (...

Weeds
March 6, 2017 1:12 PM

A bill has been introduced in the Iowa legislature that proposes classifying Palmer amaranth as a primary noxious weed.  The weed law gives counties the authority to fine landowners who fail to control noxious weeds, and, if necessary, enter...

Weeds
February 26, 2017 8:13 AM

It has been several years since I’ve added anything to the Herbicide Ad Hall of Shame, but I feel DuPont’s sales sheet for Fexapan warrants inclusion.  At a time when nearly everyone realizes we are painting ourselves into a...

Herbicide Resistance
February 12, 2017 9:47 AM

The University of Illinois Plant Clinic recently published results of their 2016 herbicide resistance screening program.  For a $50 fee the Clinic analyzes...

Herbicide Resistance
February 11, 2017 11:09 AM

Planning on attending the Commodity Classic in San Antonio in March?   Have experience with herbicide resistant weeds?  

If you are involved in crop production in Iowa, the answer to the second question is yes.  The Weed Science Society of America is sponsoring a listening session at the...

Herbicide Resistance
January 20, 2017 1:30 PM

I've been asked several times at meetings this winter if it would be possible to identify Palmer amaranth in conservation plantings at this time of year.  My response has been 'I think so, but I've never tried'.  To avoid having to use that answer in the future, I went to a field planted to...

Weeds
January 15, 2017 8:43 AM

I recently had a discussion with a farmer regarding the Palmer problem, and he asked if I were 'King for a Day' how would I change Iowa's noxious weed law.  I came up with four suggestions regarding classifying weeds as noxious:

1)  Eliminate any weed from the list that is widely...

Weeds
December 29, 2016 8:22 AM

People involved in weed management for at least 20 years probably remember corn being damaged by glyphosate drift when Roundup Ready soybean were first introduced.  The extensive damage was due to the high susceptibility of corn to glyphosate; equipping sprayers with low-drift nozzles and the...

Weeds
December 22, 2016 7:56 AM

The recent approval of the new dicamba products approved for use on Xtend soybean has been received with mix feelings by the agricultural community; many are excited about the new options to help with the growing herbicide resistance problem, whereas others are concerned about the risks...

Weeds
December 12, 2016 7:34 AM

The 2017 version of WC 94 - Herbicide guide for Iowa corn and soybean production - is now available.  The guide includes several tables providing information on herbicide effectiveness, composition of package mixes, and herbicide sites of action.  In addition the guide...

Weeds
December 5, 2016 9:29 AM

I’ll admit it, I enjoy the laughing weeds in Syngenta’s Acuron advertisements. The Acuron Chronicles remind me of something written by Dutch Sylwester more than 60 years ago.  Dutch was ISU’s extension weed scientist from 1945 to 1975, and his...

Weeds
October 17, 2016 6:26 AM

One of the more popular pages on the old ISU Weed Science website was the Herbicide Ad Hall of Shame. It featured ads that I deemed went against Integrated Pest Management (IPM) principles. Recently, two of my colleagues nominated the attached ad that promotes the effectiveness of dicamba in...

Weeds
October 7, 2016 1:57 PM

A grower provided us a sample of the seed mix used on one of the conservation plantings where Palmer amaranth developed following planting. We were able to extract Amaranthus seed from the native seed mix. Since it is difficult, if not impossible, to visually differentiate the ...

Weeds, Herbicide Resistance
October 6, 2016 7:09 AM

Palmer amaranth has been identified in newly-seeded conservation plantings in more than 30 Iowa counties, and we would not be surprised if the actual number is double that. The number of Palmer amaranth plants per acre has typically been low enough (<250 plants per acre) to make physical...

Weeds
September 19, 2016 6:42 AM

I tell students in my ID class that weed identification is easy since very few species have traits that allow them to persist in disturbed habitats, thus you run into the same weeds over and over. After a few years in the business, you seldom encounter a weed you haven’t dealt with before. That...

Weeds
September 12, 2016 12:48 PM

As you venture around the countryside this time of year you might notice the presence of a plant with white flowers along the edge of woodlands. There is a good chance this plant is white snakeroot, a perennial in the Asteraceae (sunflower family). The plant is adapted to shady areas with low...

Weeds
September 6, 2016 2:00 PM

I took my final Labor Day Palmer amaranth tour on Saturday, visiting the first three known sites of Palmer amaranth in western Iowa. First stop was Harrison County, ground zero for Iowa Palmer amaranth. The Palmer was identified in the summer of 2013 in a 50 acre fallow field; because of the...

Weeds
August 30, 2016 8:35 AM

The first step in managing any pest is correct identification. For Palmer amaranth, we have stressed the need to examine the inflorescences of female plants for the presence of the large, sharp bracts. Farmers/agronomists are not accustomed to examining flowers since almost all weeds can be...

Weeds
August 25, 2016 2:37 PM

Most people are aware of the multiple findings of Palmer amaranth across Iowa this month.  Palmer amaranth has been identified both in crop fields and in conservation plantings using native seed mixes.  Early detection is essential in order to prevent the new weed from getting permanently...

Weeds
August 14, 2016 10:13 AM

Although rain moved us indoors, we had a great turnout for the 2016 Weed Identification Contest.  This year's winner in the Professional Division is long-time participant Cindy Recker of Peosta, IA.  Cindy, a member of ISU's Crop Judging Team when she was a student, correctly identified 37 of 40...

Weeds
July 29, 2016 7:51 AM

Iowa Code 317 is the section of the Iowa Code that defines the Iowa Noxious Weed Law.  Chapter 317.1 is the piece of legislation that actually defines which...

Weeds
July 25, 2016 12:35 PM

Japanese knotweed is one of the most difficult weeds to eradicate due to its extensive woody root system.  In England it is notorious for caving in basement walls where it was planted as a foundation plant.  At least 15 years ago I discovered a 'nice' patch of Japanese bamboo along the banks of...

Weeds
July 18, 2016 11:14 AM

I’ve seen more people walking beans and had more comments about it than I can remember in a long time.  Perhaps it's time for Greg Brown to re-release his classic ‘Walking the Beans’, first released on ‘The Iowa Waltz’ album in 1981....

Weeds
July 13, 2016 1:56 PM

The current epidemic of wild parsnip has garnered much attention due to the toxins present in the plant.  Since wild parsnip is a biennial, mowing is often recommended as a control option.  The theory is that by preventing seed production, mowing can eliminate future infestations.  In practice,...

Weeds

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