Airblast Mistblowers

Airblast sprayers use a combination of air propelled by a high speed fan and liquid to deliver the pesticide to trees. Nozzles operate under low pressure which deliver the spray droplets directly into the high-speed airstream. The blast of air shatters the drops into finer droplets and blows them into the field. In Christmas trees, typically airblast sprayers direct spray only to one side as the sprayer moves forward, and are mounted to a tractor and powered through the PTO. Tank capacity may be 100 to 400 gallons. An airblast sprayer may cover a swath of up to 100 feet.

Advantages:

• quickly covers large spray areas
• uses less water
• lower labor costs
• less worker exposure to pesticides as fewer workers are needed to apply materials and tractor cabs can be equipped with safety features
• can apply materials at night when pollinators are not present

Disadvantages:

• field must be laid out with adequate access roads running parallel to each other
• drift hazard
• uneven distribution across rows — coverage of first few rows often poor
• uneven distribution from top to bottom and around all sides of the tree especially in large, heavy density trees
• poor control in the interior of blocks
• may only suppress and not completely control difficult to control pests such as balsam woolly adelgid and elongate hemlock scale
• difficult to use in small areas
• hard to confine to limited target area
• requires the use of 40 to 50 gallons of water per acre for effective control of insects which may be hard to deliver
• spraying over uneven terrain may result in uneven coverage

Most Effective Spray Pattern:

To get the best control of pests, treat 12 to 15 and no more than 20 rows at a time. Treat trees from opposite directions. Not having adequate access roads is the most common cause of spray failure. Use of a drift reduction adjuvant will not only decrease drift but result in more even coverage.

Other Types of Sprayers:

• High pressure
• Backpack mistblowers
• Boom sprayers
• Backpack sprayers