Scouting for weeds is nearly a lost art, Watters says. "When Roundup Ready crops arrived, we threw weed scouting out the window. Some weeds can produce seed in two-weeks. If you miss them, the seed bank is full, and you can have an awful time in years to come.”

Glyphosate-tolerant crops and resistance opened a door for dicamba and 2,4D-tolerant crops – and potential problems as a result, Potter says. With more than 200 weed-resistant species, there is no sure control, making scouting more vital than ever. Resistance puts increased emphasis on pre-emerge herbicides.

"Early evaluation lets you adjust your postemergent herbicides, and later evaluations let you see what worked and what didn't," says Potter. "Live and dead weeds mixed together after an application are a good indicator of resistance.”

With a wider variety of herbicides being used, Potter emphasizes scouting for off-target drift and herbicide injury.

Identification is only the first step; economic thresholds are equally important. "There have been years when we pulled the trigger to protect against aphids too early, killed off the beneficial insects and then had aphids roll in late," Watters says.

Accurate identification and thresholds require more than "drive-by" scouting. Identify a statistically valid pattern in a field and repeat it throughout the season, Watters adds. Apps like Aphid Speed Scout and Western Bean Cutworm Speed Scout from the University of Nebraska-Lincoln, offer detailed scouting and evaluation directions.

However, neither apps nor smartphones are required, assures Watters.

Whether you scout in a W, Z or a circle doesn't matter as much as getting off the same row, out of tillage paths and planter rows to find random situations across the field, he says. "Just use the same pattern each time you scout. It's not a bad idea to use handheld GPS to mark the spots where you stop.”