Tips for spraying in wind

How do you spray weeds in a timely fashion when every day seems too windy? Here are some tips:

Early spraying is important, so use low drift nozzles. Using a low drift nozzle so you can spray weeds early is better than waiting longer for a relatively calm day suitable for a finer spray.

Low drift nozzles produce a coarse spray. Ideally, you want to find a nozzle that can achieve a coarse spray at a broad range of pressures. But too coarse and you’re not getting adequate coverage, especially at low water volumes. Click here for a full article with images, including water-sensitive paper that demonstrates coverage based on droplet size and water volume.

Choose a nozzle that produces a coarse spray in the middle of its pressure range. A nozzle that produces a coarse spray through the middle of its pressure range gives you the most flexibility to change spray pattern and droplet size as you adjust ground speed and pressure.

Canola herbicides and droplet size.
—Glyphosate is suited to low drift (coarse droplet) sprays, but remember that at the low water volumes that favor glyphosate, coarse sprays may not provide enough droplets per square inch. A combination of coarse spray and low (but not ultra low) water volume is best to make sure you get droplets on even the smallest weeds.
—Liberty can work with a coarse spray nozzle but it needs at least 10 gallons per acre to maintain efficacy. Instead of increasing pressure to increase volume output consider using a larger nozzle. The Liberty label does not recommend using air induction nozzles. Click here for more Liberty performance tips.
—Group 2 products for the Clearfield system in general perform well with coarse sprays.

Aim for 100% overlap nozzle to nozzle. This provides equal coverage across the whole boom width.

Keep your boom low to reduce drift, but make sure to use a nozzle with a fan angle to provide 100% overlap at low heights. Spray from one nozzle should reach to the middle of the spray pattern of the adjacent nozzle.

Some wind is good. When spraying on dead calm mornings, spray can hang in the air, making it impossible to predict when and where it will settle. This dense cloud can do a lot of damage to a neighbor’s crop or yardsite. Bright sunny days with some wind are ideal times to spray to minimize drift damage. If those days are hard to come by, click here for tips for spraying in wet conditions.

Talk to people who might be affected. If you have to spray on days that are not ideal, talk to neighbors who might be affected by spray drift. Damaging a sensitive crop or a relationship is probably not worth the risk.

Watch sprayer specialist Tom Wolf’s webinar on this topic:


12 tips for better spraying results