Bob Hartzler
After a fairly long hiatus, a tweet from Corteva has earned a coveted spot in the HOS. This is a tough one since the company has used a farmer’s quote to disregard the principles of integrated weed management, rather than someone in marketing dreaming up an irresponsible advertisement.
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Although ‘pure’ botanists often scoff at the use of common names for plants, common names are a useful tool when working with domesticated plants and weeds since the pool of species is relatively small. One problem with common names is they may vary from location to location. When I started...
Waterhemp’s rise to the Cornbelt’s worst weed is one of the Cornbelt’s more fascinating weed-related events over the past 40 years. Waterhemp (Amaranthus tuberculatus) is native to the United States but is a relative newcomer to crop fields. Prior to waterhemp’s ascent, redroot pigweed...
Combines are the most important seed dispersal mechanism for weeds in our cropping system. While a small amount of seed may leave the field with grain, most weed seed that enter the combine with the crop are either spread throughout the field or carried to other fields. Harvest weed seed...
The spread of multiple-resistant weeds threatens Iowa’s production system. In order to slow the expansion of resistance, greater diversity in weed management is necessary. An October 21 workshop will discuss one potential alternative weed management tool that is used in other parts of the world...
Sensing an impending lackluster performance by the Cyclone football team, I spent the Saturday of Labor Day weekend touring several Palmer amaranth infestations in western Iowa. This is the 6th year of this trek, the first stop is always Harrison County at the first reported Iowa...
The current approach to weed management in Iowa is at risk due to rapid expansion of herbicide-resistant weeds. In order to preserve the efficacy of herbicides two things must happen: 1) adoption of integrated weed management, and 2) shift the goal of weed management from protecting crop yields...
The 2019 Iowa State University Extension and Outreach Iowa State Fair Weed Identification Contest was held on August 9 outside the John Deere Agriculture Building. Contestants need to identify live samples of weeds of agricultural, horticultural, and natural habitats in Iowa. Youth are tasked...
Question: If the state and county are so concerned about wild parsnip, why aren’t they out spraying it? The ditches and county roads are full of it.1
Wild parsnip is a biennial that was introduced to North America by the earliest European colonists, it is documented to have been grown in Virginia as early as 1609 as a food crop. In his 1913 book The Weed Flora of Iowa, L. H. Pammel described wild parsnip as ‘common on roadsides in...
Corn planting has been start and stop, and generally delayed this spring. In some situations the decision was made to plant and not apply nitrogen, or planting progressed so quickly that UAN (urea-ammonium nitrate solution) and herbicide applications couldn’t keep up with the planters, and now...
We have always told extension clients and students that the best tool for identifying an unknown weed is a good book, other than finding somebody who already knows what the weed is. We never thought much of the early weed ID apps that were developed for mobile devices.
One benefit of planting cover crops is their contribution to weed management. While several factors contribute to the inhibition of weeds by cover crops, the physical barrier of cover crop residue on the soil surface is most important. Research has shown a strong relationship between the...
The introduction of Palmer amaranth has the potential to significantly impact Iowa crop production in the future. But as the saying goes, there’s a silver lining behind every cloud, and Palmer amaranth’s silver lining might just be the Iowa Noxious Weed Law.
Iowa’s Noxious Weed Law has...
“Why can’t you academics get your stories straight?”, or “What is the optimum soybean seeding rate?”
Recent text from an extension client:
“Mark Licht is telling us to plant 120-140K soybeans. Tells us why more isn’t cost effective. You tell us 160K 15” rows for weeds. I wish you all would coordinate your story. The bottom line is net profit which is a holistic concept but every...
This is the final article of a four-part series originally posted in 2016 on using multiple, effective herbicide sites of action (herbicide groups) at effective rates as part of a long-term weed management system. Read ...
While herbicide resistance is not a new issue, the rapid increase in multiple resistant biotypes in waterhemp, giant ragweed, and horseweed (marestail) is limiting herbicidal options. A waterhemp biotype resistant to six herbicide groups (2, 4, 5, 9, 14, and 27) was recently identified in...
This is part three of a four-part series originally posted in 2016 on using multiple, effective herbicide sites of action (herbicide groups) at effective rates as part of a long-term weed management system. Read ...
This is part two of a four-part series originally posted in 2016 on using multiple, effective herbicide sites of action (herbicide groups) at effective rates as part of a long-term weed management system. Read...
This is part one of a four-part series originally posted in 2016 on using multiple, effective herbicide sites of action (herbicide groups) at effective rates as part of a long-term weed management system.
With the stagnant development of new herbicides and weeds seemingly...
Updated on November 2, 2018
I feel obligated to write something about EPA’s dicamba announcement, but will confess at this time I still have several questions...
While the monarch butterfly is a globally distributed species, the eastern United States population is renowned for its annual migration from the breeding range in the northeastern United States (and Canada) to overwintering sites in central Mexico. Overwintering populations of this cohort have...
It's Labor Day weekend, that means it's time for me to see what's happening at the first three Palmer amaranth infestations in western Iowa. The infestations (Harrison, Fremont, and Page Counties) were first reported in 2013. Harrison County had two fields (approximately 50 acres) with...