By Chris Dysiak

As farmers we are all looking for a faster, better, and cheaper way to do a good job. The answer to the question, "Can the Spray-Air System Sprayer help you do a better job?" is yes. You need to know, however, that this system is absolutely not for everyone.

Allow me to review the Spray-Sir System and the reasons why I chose it. The sprayer itself consists of a large motor-driven fan that pressurizes a hollow sprayer boom. on the bottom of the boom at seven inch intervals are large rubber grommets with a small winglike foil. The spray solution is introduced at low volume and water pressure into these grommets and onto the small foils. As the pressurized air leaves the boom through the grommets, the air wisks the liquid from the end of the foil. This wisking action results in a relatively small droplet that is approximately one-half the size of a conventional sprayer droplet but at eight times the number. The small droplets are carried downward with the air blast and into the standing crop.

As the solution droplets are forced down into the standing crop, their small size allows them to adhere to more of the leaf surface. The topside and underside of the leaf are well covered with the droplets. This results in superior crop coverage.

The Spray-Air model I chose is a forty-nine foot truck mount unit. To further enhance its flexibility and operation, I mounted the unit on the back of a fifth wheel trailer. I farm approximately 2,400 acres growing a mixture of cereals, oilseeds, and special crops and using mostly zero till. ~ base of operation is centrally located to the fields, but there are about seventeen miles between the distant quarter sections.

Because of the diversity of crops and the spread of the operation, I wanted a lot of flexibility in my new spray system including the ability to spray at lower water volumes.

In addition to the sprayer's 200 gallon tank, I mounted a second 300 gallon fresh water tank on the front of the trailer. I spray at about 2.5 US gallons, or 2 Imperial gallons per acre. This rate with the two tank set up means that I can enter a 160 acre field, spray it without going for water, and still have enough water to rinse the sprayer in the field and go home with a clean unit.

The following are what I have found to be the advantages and the disadvantages of my Spray-Air System. First, I will discuss the advantages. They are:

1) The small droplet size and the strong air stream give superior crop coverage.

2) The low water volume means that I do not need to use a second person to haul water nor do I need to spend a lot of time with tank refills.

3) The truck mount design gets me to the field and operating faster and with this convenience I am more likely to do that bit of spot spraying nine miles from home.

4) The fifth wheel trailer gives me the extra water and doesn't tie up the truck at the end of the field.

5) The superior crop coverage does allow me to reduce some chemical application rates, particularly with grassy weed herbicides.

By reducing chemical application rates, as mentioned above, I have been able to substantially reduce my costs. I regularly spray grasses at 60% - 70% of the label rate and receive good results. With broad leaf sprays, I normally use 80% of the label rate. These savings of 25% plus in post-emergent chemical cost have more than paid for the sprayer.

The disadvantages of the Spray-Air System are as follows:

1) The low water volumes mean using fine mesh water filters which increase the potential of problems when applying suspension and granular herbicides

2) The higher chemical tank concentration needs good agitation and results in more tank foaming.

3) The low water volume requires the use of an automatic spray rate controller if you want high application accuracy, and more machinery means more cost and breakdown.

4) The stream of air blowing from the pressurized booms can cause dust problems in dry condition.

5) Reducing chemical applications is a learning process mostly accomplished by trial and error.

Further to this last point, published rates are for generally all growing conditions and they include a safety margin. Excellent conditions with lush, succulent crops will allow for 40% - 50% reduction in application rates; these conditions do not happen as often as a person might think. For example, some chemicals will work better with evening application rather than with morning application. The quality of crop stand is important too, as good crop competition is vital to reducing rates. My experience has been that it is better to spend that extra dollar or two per acre on chemical than to respray a field.

In summary, if you are willing to pay attention to the little things, if you are willing to spend the time on being truly aware of individual field growing conditions, and if you are interested in cutting your input cost without hurting production, then the Spray-Air System of field sprayer may well be for you.