Despite the ag science community’s quest to manage Mother Nature, she often has other ideas. A new challenge to farmers appearing in recent years is palmer amaranth. The weed can grow 10 feet tall, has stems as thick as a baseball bat, and if tossed into a field, can reroot itself. Purdue University research has shown a 78% soybean yield loss due to infestation, 91% for corn.
Palmer amaranth grows quickly, making timely herbicide treatment crucial. Other measures, such as reducing soybean row width, keeping the plants from going to seed, and planting cover crops can help reduce the pest’s impact.
Palmer amaranth is on the move from the South into the Midwest and scientists at Kansas State University have confirmed a variety resistant to dicamba and 2,4-D. The Group 4 products have worked in the past, but are proving less effective in recent years. The research is ongoing.
HOW TO MANAGE WATERHEMP
Waterhemp is another unwanted plant that can do serious damage to yields. University of Missouri researchers have now identified a population with resistance to six herbicides. Dicamba and glufosinate were the only two of eight herbicides applied that produced weed control.
Experts recommend a blend of biological, mechanical, and cultural measures to attack the weed. Identification, timely treatment, layering herbicides, planting narrower rows, and using new technologies, all while keeping an eye on other weeds may help.
Herbicide resistant waterhemp has also been identified in Illinois, the first broadleaf species to show Group 15 resistance.
Scientists chalk the resistance up to evolution. Farmers have traditionally applied pre-emergence residual herbicides, but now experts are rethinking the year-over-year practice and the changes in plant biology that result.
USING INSECTICIDES
Resistance is also a problem for insect control. Corn rootworms adapt to control programs, including hybrid corn varieties developed with pest control in mind. Luckily, rootworms don’t travel far, and resistance is often contained to the field where it developed.
Rotating crops can help; even a one-year soybean break can disrupt the rootworm life cycle and lower population density. Some have found using foliar insecticides that kill adult beetles can help, but products are becoming more restricted.
New insecticides are in the development stage, but it may be some time before they hit the market.
Bt traits in corn may not be as effective against rootworms as they were before the rootworms caught on, but the science does protect against European corn borer (EBC). Near eradication of the pest has caused some farmers to plant hybrids without corn borer protection.
For those wanting to use less expensive seed, ECB can be controlled via other means, but fields will require diligent scouting and immediate action.
FUNGICIDE
Safe and effective use of fungicide, like any other pest control product, requires strict adherence to label directions. There are various classes of fungicides, some are curative and some are preventative. All work best before disease is present by preventing spores from germinating.
Again, ardent scouting and timing are crucial.
BEWARE PESTICIDE DRIFT
Safe pesticide application also includes awareness of pesticide drift. Both you and your neighbors will suffer if the product goes astray. Not only can yields be reduced, but in some cases, applicators may be liable legally.
Pesticide drifting to unsuspecting plants in the crossfire can cause environmental damage, including destruction of pollinator and wildlife habitat. So, make sure you are using the right product, at the right time, with the right equipment, under the right weather conditions. Generally you will want wind speeds of less than 10 mph.
Talk to you insurance agent about coverage against damage to yours or your neighbor’s crops. Know your coverage and your limits.
And always, always, always treat any pesticide with the utmost care. Used incorrectly, they can become an environmental hazard. Used correctly, they can protect your crop and your farm’s profitability.
Safe and effective use of fungicide, like any other pest control product, requires strict adherence to label directions. There are various classes of fungicides, some are curative and some are preventative. All work best before disease is present by preventing spores from germinating.
Again, ardent scouting and timing are crucial.
BEWARE PESTICIDE DRIFT
Safe pesticide application also includes awareness of pesticide drift. Both you and your neighbors will suffer if the product goes astray. Not only can yields be reduced, but in some cases, applicators may be liable legally.
Pesticide drifting to unsuspecting plants in the crossfire can cause environmental damage, including destruction of pollinator and wildlife habitat. So, make sure you are using the right product, at the right time, with the right equipment, under the right weather conditions. Generally you will want wind speeds of less than 10 mph.
Talk to you insurance agent about coverage against damage to yours or your neighbor’s crops. Know your coverage and your limits.
And always, always, always treat any pesticide with the utmost care. Used incorrectly, they can become an environmental hazard. Used correctly, they can protect your crop and your farm’s profitability.

