It’s Not a Good Agricultural Practice If You Get My Drift

Pests, diseases and weeds – they’re a fact of life for farmers.

When they get out of hand and threaten the crops, growers often have to resort to chemical treatments. It has been especially true this season due to the wet winter.

For almond growers, for instance, weeds have been literally growing like weeds in their orchard. Fungus issues have been a constant threat. And pest issues are starting to crop up.

“We have had a lot of applications,” almond field scout Jenna Mayfield observes. “People who are making all the money this season are probably the applicators.”

Pesticide drift impacts crops, workers and the environrnment.

Jenna is reminding everyone about being mindful of drift when applying herbicides and pesticides.

Drift can be an issue that not only impacts the grower’s farm, but the neighbor’s operations as well. It also can affect the health of workers and water quality.  “Almonds are a high value crop. You don’t want  drift from a nearby field to damage the almond crop,” Jenna says.

 State and local regulators continue to toughen rules on pesticide drift. This year, the state is developing new rules about applications near schools – regulations that will become effective on January 1, 2018.

In recent years, the Almond Board of California has funded research that has demonstrated how improving the accuracy and efficiency of spray applications can generate better returns to growers while reducing drift onto the orchard floor and off site. Simple changes such as slowing sprayer speeds and volumes and modifying nozzles can bring better results.

Growers can take some basic steps to minimize drift.

In an Almond Doctor column, UC Cooperative Extension (Fresno County) adviser Kurt Hembree offered these tips to minimize drift from a ground sprayer:

1. Don’t spray when it’s windy: Do not spray in winds above 6 – 10 mph.

2. Be cautious on calm days: Do not spray under dead calm conditions in early morning, evening or the night. Calm conditions are often associated with temperature inversions which can result in long-distance spray drift (1 mile or more).

3. Check the buffer zones: Refer to the product label to determine adequate buffer zones outside of the field treated. Do not spray if the wind is blowing towards a nearby sensitive crop, garden, waterway, or other sensitive area.

4. Use a shield: Consider equipping your sprayer with a protective shield. A number of designs are available that can reduce drift between 35 and 75 percent. Avoid spraying trunk-to-trunk with unshielded spray booms.

5. Use a spray drift retardant: Spray drift retardants are available that can be added to many products to help reduce off-target drift.

6. Check the formulation: Use amine formulations of 2, 4-D when possible. Use special care when using ester or other volatile herbicides. Avoid spraying these products on or immediately before hot days.

7. Sprayer type: Sprayers designed to apply herbicides at low volumes (<10 gpa), such as controlled droplet applicators, produce extremely fine droplets which can drift long distances. Advances in sprayer technology allow for certain post emergence herbicides (like glyphosate) to be applied through low volume, shielded equipment or in low doses based on weed populations present at the time of treatment.

  8. Watch the nozzle pressure: Avoid nozzle pressures above 45 psi for conventional flat fan tips. Excessive pressure can create fine droplets that are prone to drift. Use a minimum of 10 gallon/acre, unless otherwise specified on the label.

 9. Nozzle height: Operate nozzles at their lowest recommended height. For 80 degree tips, this is 18 inches, and for 110 degree tips, this is 12 inches. Orienting nozzles forward also allows for further height reductions. 10. Nozzle selection: Special nozzles are available by various manufacturers that create coarse, low-drift sprays. These nozzles can reduce drift by 50 to 95 percent.