Herbicide Spray Drift Demonstration

Herbicide Spray Drift Demonstration


Today we’re looking at a series of
herbicide drift demonstration plots. The purpose of this
demonstration is to show people the off-target
movement possibilities and capabilities of
different droplet size classifications. The application rates here were 64
ounces of glyphosate applied with a 30-foot sprayer at approximately how forty pounds of
pressure and this application how was applied on June 28. The first
plot that we’re going to be looking at is an XR flat fan plot. In this situation the nozzle so was an
02 size in terms of volume and the
spray droplet classification here will be classified as fine. In terms of
the area that was sprayed behind me we have
the oats in a situation here and you can see it’s
turned brown from the application of the glyphosate at 64 ounces and the white pole in the background
indicates that where the boom stopped
immediately in the area to the right or to the south of
me is green and that situation shows the fact that was not applied. but because of the wind speed that
occurred at the time of application which varied anywhere between five to 17 miles per hour, we did have off-target movement into the untreated area that was not
directly applied and you can see the result in
terms of damage to the oats when the fine droplets did move off-target and that’s something we normally see with a fine droplet type of a nozzle
and the flat fan. There’s a percentage that’s always
fine and has the ability to move off- target. The second plot that we’re going
to be looking at is a turbo flat fan. This style of nozzle from Spraying Systems
Company is similar to a flood jet laid on
its side. It has a turbulence chamber but it is not air induction. It produces
droplets that are more concentric and more even in size. The classification here would be a
medium-size droplet for the primary area. It can
become small depending upon the pressure range that was applied. Again it’s an 02
nozzle size and if we look back to our pole here
at the end of the plot and immediately to your right or farther to
the south you’ll again see some off-target movement,
but maybe not quite as much as we had enough in fine droplets classification for the
XR flat fan previous to this but certainly there’s a percentage of
droplets that are capable at normal pressures
here at forty to forty-five PSI of moving off target. The next nozzle that we’re going to be
looking at he is a style called turbo twinjet. This is evident of
the nozzle styles that have a dual outlet or 2 openings as opposed to one outlet.
Previously we looked at a turbo flat fan that had just one single outlet. This is
the same style of nozzle. In this situation, we have two
openings. The idea behind two openings is to improve weed control, improve efficacy of pest control, et
cetera., at one time looking at the possibility
of this style nozzle with twin outlets used for fungicide applications in
soybeans such as for the potential soybean
rust in the southern United States. In this situation we would also call
this a medium size classification of droplet although at higher pressures it can
become small rapidly. In this situation we have some off-target
movement, but again less than we had at the
earlier plot where we had an XR flat fan or fine droplet. In this
particular plot we are looking at a nozzle style that provides a coarse
droplet. This happens to be this situation
involving a tip that actually uses an air induction principle. We have air filled droplets and they
become much larger in the coarse category. This
happens to be one that has a dual twin-jet outlet from Spraying Systems
Company, and in this case, the control
pattern is very good but also the degree of off-target movement has been lessened to some degree because of the size of the droplets,
even though we are into some plot areas that were subject to increasing wind speeds during the application time. In this
particular plot we are looking at a nozzle style called an air induction flat fan. We are looking
at a very much of a flat fan pattern, similar to the very first
plot that we looked at with the marriage of an air induction capability called an AIXR operated at forty PSI. This style of nozzle
is capable of developing and delivering a coarse droplet as well as a medium sized droplet very
adequately within the different ranges. Its a nozzle style that works well
with automatic spray controllers because of the fact that pressure may be
going up and down and holding its pattern very well, but in this case the principal and take
home message here is a flat fan product in terms of
developing very good efficacy but as well as coarse
droplets. In this situation we seem to have a
capability of holding that line in terms of drift
management. This last style of nozzle is probably
the most striking we have today in our field plot demonstrations.
this happens to be a turbo TeeJet induction style nozzle that develops and
delivers ultra coarse droplets almost entirely through all
pressure spectrum, anywhere from between 15 to 20 pounds of PSI well up to sixty or higher making it
very suitable for systemic products such as glyphosate, dicamba, other types of products where it is very important to absolutely limit off-target particle movement to sensitive crops and
sensitive areas downwind. In this particular situation, we’ve had
wind gusts between 12 to 17 miles per hour that came through and I think it’s very
striking in this situation that the droplet sizes were large enough
not to move off target but yet adequate in terms of the control for giant ragweed that’s in the plots as
well as for the oats and it gave satisfactory control again at a fairly high rate of glyphosate at 64 ounces but certainly efficacy was provided
for that. But again, has a fit for systemic situations much more than it would be for a contact action
where we would probably not recommend its placement. So, again, very specific and will become I
think a popular tip in the future for a lot of those
systemic products and specific crops.

2 thoughts on “Herbicide Spray Drift Demonstration

  1. Dear Sir, I liked your demonstration, can you answer my question please, As per my understanding the air induction nozzles have clogging problem during field operation, there is any solution for that problem. And secondly for very large droplets the runoff could be a big problem which will contribute the runoff and cause soil and ground water contamination.

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