Controlling weeds is probably a notch or two higher on your priority list this spring than it has been in the past. Glyphosate resistant weeds are making it tougher to get clean fields without adding soil residual herbicides, and/or mixing up the chemistry. It's all about spraying herbicides with multiple modes of action to prevent further resistance from developing.
If you're going to spray residual herbicides, something some haven't done for a while, you need to make sure you get uniform coverage across the soil surface. Greg Lundquist, AgroChem, Wabash, says he's been getting questions from customers about whether they should replace nozzle tips before this spraying season begins.
The materials most nozzles are made of today, a poly material, wears very well, he says. However, even it can eventually wear to the point where nozzles aren't delivering a consistent pattern across the soil surface.
"I first ask guys how many acres they have sprayed on this set of nozzles," he says. "Depending on how much they farm and how many trips they make per year, it isn't uncommon to have 10,000 acres on a set pretty quickly. If you've sprayed that many acres, it could be time to opt for new nozzles."
There are a couple ways to check rather than just making the switch based on acres, he notes. First, you can stand behind each nozzle and collect output in a measuring cup over a specified time. Calculate the amount of liquid that you should collect, and see if it is the same from each nozzle.
The second way is to simply stand behind the boom while it sprays water in the barn lot. "Look for streaks and skips ion patterns coming from a nozzle," he suggests. "If you can pick up streaking or skipping in the nozzles, then that's a pretty sure sign it's time to change them without going any further," he says.