Selecting Spray Nozzles to Reduce Particle Drift

This technical bulletin presents characteristics drift watch   of various nozzles to allow the efficacious utility of pesticides and to decrease particle motion to non-goal organisms and soil.
Tom Peters, Sugar Beet Agronomist, NDSU Extension Service
Andrew Thostenson, Pesticide Program Specialist, NDSU Extension Service; John Nowatzki, Agricultural Machine Systems Specialist, NDSU Extension Service; Vern Hofman, Professor Emeritus, NDSU Agricultural and Biosystems Engineering Department; James Wilson, Pesticide Training Coordinator (retired), South Dakota State University
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Determine Your Needs
Pesticide Label Compliance
Low-particle-waft Nozzles
Nozzle Costs
Drift Management Strategies
Droplet Size Classification
Selecting Spray Nozzles
Conventional Nozzles
Extended-variety Flat Fan
Drift-discount Nozzles
Turbo TeeJet Nozzle
Hypro Guardian
Venturi Air-induction Nozzles
Greenleaf TurboDrop
Greenleaf TurboDrop XL
Greenleaf TurboDrop XL-D
Greenleaf AirMix
Air Bubble Jet
Hardi Injet
TeeJet Air Induction (AI)
Turbo TeeJet Induction Nozzle
Air Induction XR Flat Fan
Hypro Ultra-Lo-Drift
Hypro AVI, Air-inducing Venturi
Delavan Raindrop Ultra
Hypro Guardian Air
Other Drift-discount Technologies
Capstan Ag Syncro Blended Pulse and Raven Spraying System
Issues to Consider
Venturi Tip Spray Pressure
Nozzle Size Selection
Boom Height
Nozzle Wear
Nozzle Plugging
The Bottom Line
Nozzle Manufacturers1

“What nozzle ought to I use?”

That’s a complicated question. And the solution to the question is becoming extra complex, specially with extra emphasis on tank-combos to deliver multiple effective pesticides in opposition to goal pests. Some of the numerous nozzles in the marketplace can lessen particle go with the flow. Would those nozzles be proper for you?

Whether a low-drift nozzle suits your program relies upon upon your spraying desires and operation. Drift-reducing nozzles generally produce larger droplets and penetrate the plant canopy while goal flora are larger, but larger droplets may shatter and be misplaced to the soil surface while the usage of touch pesticides and goal plant life are small.

Nozzles that produce smaller droplets provide better insurance and the pesticide is retained better at the leaf surface, mainly while the goal plant is smaller. However, small droplets are greater liable to particle waft.

Which scenario is right for you? Probably a aggregate of each.

Determine Your Needs
Consider your priorities before making your nozzle choices. Nozzles are fantastically cheaper, however they may be the most important component of your spray device.

Should you be concerned approximately particle waft?

Are you the use of highly energetic or nonselective herbicides and herbicide-tolerant trends?
Does the pesticide label specify nozzle selection and spray volume?
Are you spraying close to sensitive plants or touchy regions (shelterbelts, neighboring fields, rural houses)?
Does the label specify environmental situations (wind velocity, relative humidity and air temperature) while you will be spraying?
Are you involved about the impact of pesticide glide at the surroundings?
The Environmental Protection Agency (EPA) has weighed in, developing a policy to inspire the development of spray technologies scientifically demonstrated to lessen particle drift. To comply with coverage, pesticide and adjuvant manufacturers will decide every new pesticide’s potential for go with the flow, considering software ground pace, spray stress, nozzle selection, pesticide, pesticide-aggregate, adjuvant and wind pace.

New pesticide labels will comprise written tips for ensuring more of the carried out pesticide reaches the crop and, accordingly, enhancing normal pest control and reducing the loss of pesticide from the target.

Pesticide Label Compliance
Whatever nozzle you select, the pesticide label is the law and continually have to be accompanied. You might be breaking the regulation in case you go with to spray if a pesticide label prohibits utility above a selected wind speed.

Be aware that go with the flow-reducing nozzles most effective lessen particle flow; they do not take away all flow. Spraying when a susceptible crop is downwind still might also cause harm. Drift-reducing nozzles do now not reduce volatility.

This book summarizes traits of conventional and coffee-go with the flow nozzle technologies, demonstrates the nozzle and includes an photo on water-sensitive paper of the spray deposit it produces. The pictures were constituted of nozzles with water volumes of about 8 gallons/acre for all nozzles at their standard or top-quality pressure. Spot cards were sprayed lying on a horizontal surface and do not imply coverage on an inclined or vertical surface.

Figure 1 compares the relative flow constituted of a fashionable flat fan, a pre-orifice flat fan and a venturi nozzle. The venturi nozzles indicates approximately a ninety percentage reduction in go with the flow, as compared with a flat-fan nozzle at general pressures. Figures 2 and 3 compare the differences in drift among a flat fan and a waft-lowering venturi nozzle.

Figure 1

Pressure loss across the length of the increase may additionally motive variation within the discharge from nozzles, so checking running pressure along the boom is crucial to make certain it’s far uniform and at the nozzle manufacturer’s minimum pressure.

Low-particle-flow Nozzles
Low-flow nozzles are designed to supply large spray droplets with fewer driftable fines. Larger droplets are produced with the use of a pressure-decreasing chamber in the nozzle and with numerous nozzles by using incorporating air into the spray droplets. These nozzles are brilliant at decreasing however will no longer cast off all waft. You nonetheless must use warning whilst susceptible plants are downwind.

Spray insurance is commonly reduced while particle float is decreased through increasing droplet size due to the fact fewer droplets may be deposited on the plant. Larger droplets combined with low service rates may not offer adequate coverage and could lessen the effectiveness of the software.

Low-flow nozzles normally are advocated to be used with systemic pesticides that translocate within the plant and commonly do not require entire insurance of the leaf surface. Low-go with the flow nozzles normally are not endorsed for use with touch-type insecticides. Consult the pesticide label for precise regulations.

Nozzle Costs
Nozzle fees range extensively. Nozzle guidelines made from chrome steel or ceramic typically cost greater than plastic guidelines however usually final longer. Nozzle designs that include air induction generation additionally usually cost greater than popular flat-fan nozzles, however again, the cost can be well worth the extra expense if they prevent glide damage.

A flow problem frequently can fee heaps of dollars, so some greater dollars for a set of flow-decreasing nozzles may be a worthwhile investment.

Drift Management Strategies
The maximum important element in lowering drift is the size of the droplets produced with the aid of the nozzle. For conventional flat-fan nozzles, the nice approach to lowering excellent droplets is to growth the nozzle orifice length and reduce the spray increase operating stress.

Another concept is to consider the usage of a a hundred and ten-diploma nozzle. It allows a decrease increase height and offers the wind much less possibility to hold small drops away even though it produces a smaller drop.

Booms need to be set as little as possible above the goal, based totally on nozzle discharge angle and nozzle spacing, whilst preserving uniform coverage. Check along with your nozzle manufacturer to fit right boom height and overlap.

Droplet Size Classification
The American Society of Agricultural and Biological Engineers (ASABE) gives a Droplet Size Classification System that is a helpful aid in choosing spray nozzles. The category tiers from extremely best to ultra-coarse (Table 1).

Table 1

This widespread is based totally on the average size droplet, known as the volume median diameter (VMD), measured in microns, this is produced at an working strain. One micron is 1/1,000 millimeter, or approximately 1/25,000 inch. In evaluation, a human hair is set one hundred microns in diameter.

The VMD is a droplet dimension that shows half of the spray quantity is in droplets smaller than this wide variety and half of of the spray volume is in droplets large than this length. It also often is indicated by way of Dv0.5.

Two other important values are the 10 percentage quantity and 90 percent extent droplet length indicated by way of Dv0.1 and Dv0.9, respectively. The Dv0.1 cost suggests that 10 percent of the spray quantity is in droplets smaller than this fee and can be a chief a part of the waft-prone fines. For great glide control, this number ought to be near or above 200 microns, so that you can help minimize go with the flow.

The Dv0.Nine price shows that 90 percentage of the spray volume is in droplets smaller than this cost, or 10 percentage of the spray volume is in droplets larger than this fee. A big range indicates excessively huge spray drops could be produced and can result in bad leaf coverage or droplets misplaced to nontarget regions together with the soil.

Newer soybean varieties designed for use with glyphosate and 2,4-D or glyphosate and dicamba generally have to be sprayed with nozzles that produce an “extremely coarse” or “ultra-coarse” spray drop. This records is based totally on the Spray Drop Classification System (Table 2).

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