By. Dr. ElRay Roper, Senior Technical Representative, Syngenta
Pest Management Professionals (PMPs) have a variety of tools available to help them manage insect pest populations, and the proper use of each of these tools is vital to achieving control. This article will discuss the proper application process for granular insecticides.
There are several key points to remember about granular insecticides, including:
- Granules are generally manufactured by applying an insecticide onto a carrier particle
- Carriers include corn cob grit, sand, compressed cellulose and fertilizer.
- Granular insecticides are applied dry to open areas
- The insecticide is activated and released from the granule when it contacts water
- Many granular insecticide labels require that the area treated with the granules be watered immediately after application to assure release of the insecticide.
Where to Use a Granule Insecticide
Granules are designed to treat the following areas:
- Turf
- Mulch such as pine straw or coarse bark
- Low growing ground covers
- Vegetation where liquid sprays will not reach the soil
It’s also important to remember that granules should be swept or blown from hard surfaces such as sidewalks and driveways back on to the target areas. If they are left on hard surfaces the active ingredients can end up in waterways instead of controlling insects for your customer.
How to Apply a Granule Insecticide
Granules work best when uniformly applied over the treated area. Granules are usually applied using a mechanical fertilizer spreader. There is a variety of spreaders available and your distributor can help you select one that is best for your needs.
Each granular insecticide label specifies a weight of the product to be applied over a certain area. Before application, it is important to calibrate your applicator to know how much material you will be applying. PMPs can use the following four steps to calibrate granular applicators and to determine how much area is being treated per pound of product.
Determining area treated per pound of product:
- Step One: Determine the area treated by your spreader for a given opening setting.
- This area is the width of the spread pattern multiplied by the length of your step.
- For example, if the spread pattern on your spreader is 10 feet and the length of your step is three feet, the area that you treat per step is 30 square feet.
(width of spread) x (length of technician’s step) = area treated per step
- Step Two: Weigh 1 pound of granules into the applicator.
- Step Three: Count the number of steps required to empty the spreader.
- For example, say it takes 20 steps to empty your spreader.
- Step Four: Multiply the number of steps by the area per step.
- For you, this calculation is 20 steps multiplied by 30 square feet per step.
(area treated per step) x (number of steps to empty one lb) = area treated per pound
In the example, if it takes 20 steps to apply one pound of granule at 30 square feet per step, then one pound is being applied to every 600 square feet. At this rate you will be applying 1.67 pounds per 1000 square feet.
1000 .
area treated per pound = rate per 1000 sq/ft
If you use the Syngenta granule, Demand® G, the label calls for two pounds per 1000 square feet. You now know that you're treating at 1.67 pounds per square foot and need to adjust the calibration to achieve the label rate.
How can you adjust?
- Increase the spreader opening setting
- Adjust speed by walking more slowly
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