Worries over the spread of glyphosate-resistant weeds apparently have become a reality, according to a survey by BASF.

Seventy-six percent of the growers surveyed suspected glyphosate resistance was a cause of their tough-to-control weeds this past growing season and already have changed their management program to address the issue.

In addition, many growers have experienced lower yields, which they attribute to resistant weeds. These growers also have spent more time scouting and invested more money in their crops due to resistant weeds.

In the survey, growers identified how they plan to change their programs in 2014.

More than two-thirds of growers indicated that they would be applying a pre-emergence herbicide this season, and more than half of growers are planning to add an additional herbicide to their existing program.

Additionally, 50 percent of growers plan to use more than one site of action, and 47 percent said they plan on using overlapping residual herbicides to control resistant weeds.

The survey also highlighted the weeds that growers found the toughest to control in 2013.

Nearly two-thirds of respondents said waterhemp was the most difficult to control, while 54 percent said that ragweed species were the toughest to control. Lambsquarter and marestail also were identified as difficult weeds.

Weed management isn’t as simple as it was a decade ago, and growers need to use residual herbicides and multiple modes of action in their approach. If not, it’s time to sharpen the old gardening hoe and start walking fields like we did back in the day.