I agree with Peter Werts' comments. At the Hudson Valley Lab, Peter Jentsch
and I set up a tall spindle orchard (3 ft X 11 Ft) about 5 years ago. We
decided to spray it with a home-made vertical boom attached to a 3-pt hitch
Pac-Tank sprayer, using air-induction nozzles as Peter Werts suggested. When
we looked at coverage following applications of Surround, it appeared that we
were getting pretty decent coverage on 3 and 4 year old trees. However, the
reason that I would not recommend this to others is that effective coverage
without the air-assist is dependent on using water rather than air as the
propellant. Because we need to maintain high pressure at the nozzles to get a
decent trajectory of the spray droplets, we found that we needed a minimum of
150 to 200 gallons of water per acre, depending on travel speed of the sprayer.
Even on small blocks of 3 to 5 acres, the need to refill the sprayer so
frequently is a real disadvantage. As I recall, at the time we built our
sprayer, the air induction nozzles had a some limitations that meant we could
not set them up to deliver really small quantities per minute, and that limit
along with the need for pressure to create a droplet trajectory, made it
impossible to develop a low-volume boom sprayer for the tall spindle spacing.
We might have been able to use less water if we used conventional nozzles to
create a mist, but then the small spray droplets would not have had enough mass
to penetrate the tree canopy.
I much prefer to spray our small orchard blocks with our 3-pt hitch TurboTeuton
mist blower which we have calibrated to deliver 50 gal of spray per acre,
although one could deliver much higher volumes if desired. The tank on our
model holds about 130 gal of water, but the same kind of sprayer design is
available in a trailer-mounted design. (I’m sure that there are many other
sprayers that could be set up to accomplish the same things that I have
described above. I’m not trying to promote any one brand, just relating
personal experience.) The advantages of this sprayer (from my perspective) are
that
(1) it is a tower sprayer with an infinite number of adjustments for
height, angles of air delivery, nozzle arrangements, etc..
(2) We can maintain uniform output and nozzle pressure at relatively low
fan speeds. That means we can use lower PTO speeds while maintaining
calibration so long as we use higher gears to maintain ground speed. I found
that I can operate this sprayer at three different gear/RPM settings while
maintaining 3 mph ground speed. The lower RPM is very useful for small trees on
a calm morning whereas higher RPM is necessary to fight wind or cover larger
trees.
(3) The sprayer is relatively quiet compared to most air blast sprayers,
and that is a real advantage for orchards that are close to neighbors. I wish
we had a standard comparison of sprayer decibel levels when the sprayers are
operating at comparable RPMs because small growers with noise-sensitive
neighbors should certainly consider the noise factor when purchasing a sprayer.
The disadvantage of the TurboTeuton that we have is that it does not move
enough air to fight winds greater than about 6-8 mph, and for that reason it
will not work well on large trees or in orchards with rows more than about
15-18 ft apart. However, I am convinced that tower sprayers are essential
for spraying tall spindle orchards with minimal drift.
********************************************
Dave Rosenberger, Plant Pathologist,
Hudson Valley Lab, P.O. Box 727, Highland, NY 12528
Cell: 845-594-3060
http://blogs.cornell.edu/plantpathhvl/blog-2014/
********************************************
On Mar 27, 2015, at 10:29 AM, Peter Werts
<pwe...@ipminstitute.org<mailto:pwe...@ipminstitute.org>> wrote:
Hi Tatum,
I have calibrated 20+ airblast sprayers in Minnesota and Wisconsin over the
last two years, many for growers with tall spindle systems. I still think the
airblast sprayer is still the way to go. There is much you can do with sprayer
calibration to improve performance and accuracy of pesticide deposition. I
received my training from seminars led by Dr. Andrew Landers, Ag engineer at
Cornell. I think his work is right on target to address your questions. If
you have the time to research and read about your options I would get his book,
“Effective Vineyard Spraying”, http://effectivespraying.com/. This publication
offers an in-depth review of all sorts of sprayer technology and how to select
for your production system.
A couple considerations could include:
1. Look for an airblast sprayer with an adjustable fan speed or a lower fan
speed. Reducing the fan speed will help you keep your sprays on target! I
know AgTec makes a vineyard sprayer with a lower fan speed. The AgTec’s have
been real popular in the upper Midwest, though I don’t think they are the
standard in New England or Mid Atlantic. This sprayer from Durand Wayland is
an example of a rig with a multi-speed gear box for the fan and the option for
a tower attachment, http://durand-wayland.com/spraying/redline_600HP.html
2. Buy a sprayer that will allow you to use air-induction nozzles.
Air-induction nozzles encapsulate little bubbles of air inside the droplet,
creating a larger droplet less prone to drift. When this larger droplet makes
contact with the plant surface, it breaks into smaller droplets.
3. Regarding your concerns for pesticide drift to neighboring organic farms,
proper calibration is essential regardless of what sprayer you purchase.
Additionally, documenting your air temperature, wind speed and direction, on
days you spray will demonstrate your awareness of this risk to the neighbors
and may help mitigate accusations of drift, if such unfortunate events occur.
Thanks,
Peter
=============================
Peter Werts
Project Manager
Specialty Crops
IPM Institute of North America, Inc.
1020 Regent St.
Madison WI 53715
Office: 608 232-1410
Cell: 612 518-0319
Fax: 608 232-1440
pwe...@ipminstitute.org<mailto:pwe...@ipminstitute.org>
www.ipminstitute.org<http://www.ipminstitute.org/>
From:
apple-crop-boun...@virtualorchard.net<mailto:apple-crop-boun...@virtualorchard.net>
[mailto:apple-crop-boun...@virtualorchard.net] On Behalf Of Tatum Stewart
Sent: Thursday, March 26, 2015 3:07 PM
To: apple-crop@virtualorchard.net<mailto:apple-crop@virtualorchard.net>
Subject: [apple-crop] Airblast Sprayer for Tall Spindle?
I have a small (3 acres) established orchard on M7 that I have worked for about
10 years. I have some new land about 15 miles away that I have began planting
a new orchard using the Tall Spindle method. I only have about one acre
planted now, but it will end up being about 5 acres of apples as PYO. I also
have peaches and blackberries.
I have been planning on purchasing a new airblast sprayer for the new orchard
in the future so that I don't have to haul it and my tractor back and forth
from each place. And it is hard to get good spray timing when the sprayer is
at the other orchard.
However, do I need an airblast with the tall spindle system? With the M7 trees
and bigger you need the air to push through the tree to ensure good coverage,
but with the M9s the canopy is so much smaller. Could you not use a tower type
sprayer with-out the airblast? Drift would be greatly reduced (a big deal with
organic farms on surrounding my property), Tractor requirements would be less
allowing for tighter row spacing, and obviously the cost would be less.
What would be the down side? Poor coverage of the underside of the leaves due
to no swirling air? Droplet size too large?
Thanks
Tatum Stewart
Stewart Orchard
Ashland City and Nashville, TN
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