If there’s one thing that farmers can count on, it’s that weeds will return every summer and threaten to crowd out crops in the field, says Meaghan Anderson, central Iowa field agronomist for Iowa State University Extension and Outreach.

“It’s a weed’s job to occupy disturbed soil,” Anderson says. “It’s why weeds show up, in a week or two, in grass. It’s why they show up in crop fields. And weeds can cause very significant (crop) losses. We have to manage weeds every year, because if we don’t stay on top of it, they just get worse and worse.”

Without crop protection products, U.S. farmers would lose an average of 52% of their corn crop and 49% of their soybean crop, according to the Weed Science Society of America.

Anderson says one particularly nasty field weed, known as waterhemp, can produce thousands of seeds if allowed to reach maturity.

“That’s half a million potential plants waiting in the soil to come up next year,” she explains.

Farmers use a variety of weed prevention strategies throughout the year to protect their crops.

Before spring planting begins, farmers select seed varieties that are resistant to problem pests and diseases.

Farmers also use precision ag technology on their planters to optimally space the seed rows – down to the inch or less – so as the crops grow, the plants shade out any weeds.

In addition, farmers work with agronomists to scout fields throughout the growing season, Anderson explains.

If pests start to threaten the crop, beyond what experts consider an economic threshold, then crop protection products may be necessary, Anderson says.

Farmers use application equipment with row shut-offs so they only apply as needed to specific sections in the field, Anderson notes.

The newest precision technology uses smart cameras and machine-learning to identify emerging weeds as the equipment moves through the fields, so applications are targeted only to the weeds.

When you see an applicator working a field, over 75% of what’s applied to the crop is actually water, Anderson says.

In reality, farmers apply only about 1 soda can of crop protection products and 15 gallons of water for every 1 acre field.

“We have a lot of (crop protection) products nowadays that we use only ounces per acre or fractions of an ounce per acre,”
  - Meaghan Anderson, weed scientist and central Iowa field agronomist for Iowa State University Extension and Outreach

Farmers continue to adopt new technologies and work with agronomists to stay up-to-date on the latest weed management strategies, Anderson says.

“There have been amazing advances (in crop protection) to make us safer, and this is something that is just going to get better and better all the time,” she adds. “There’s a lot of research going on, and farmers are learning all the time about new practices.”

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