The Combine Forum banner

Water volumes with fungicide

6K views 19 replies 14 participants last post by  custom_farmer 
#1 ·
Just curious if anyone has any experience with lower water volumes and fungicides. Local spray plane sprays 2 gal/acre and charges a dollar more than ground which will spray up to 20 gal/acre reluctantly. I have used the plane in the past and it seems to work ok at 2 but i asked about spraying 4 gallons and rate almost doubled in price. I never done any trials but wondering if anyone else has and what your thoughts are. I usually hire the plane for some acres just to keep him around but i would still like to know if im getting value from the fungicide at the low rate?
 
#2 ·
I spray my own fungicide with a ground rig but I try to let mother nature put the water on for me. If I can spray in a super dewey morning, then I cut back to 10 gpa. I use a good sticking agent like APSA 80 or Rainfast, so theres no runoff. If leaves are bone dry, then I go to 13-15, depending on field size. Have had good success so far
 
#3 ·
I think with the plane the conditions are more important than the water volume. I wouldn't allow spraying in a hot or windy day but have had the plane spray some on a calm evening several years ago and it gave excellent coverage at probably similar water rates.

Having said that I do all my own spraying if possible, usually contact herbicides and fungicides at 9.2 GPA because that's 120 acres on the 1100 gallon tank. Usually run at close to 100PSI through air induction nozzles and the coverage is excellent. Again I will shut down mid-day if it's hot or windy.
 
  • Like
Reactions: Licensed to kill
#6 ·
If you need penetration of the canopy with a fungicide like getting to the bottom of a lentil for anthracnose protection, then a ground rig with lots of water is the only way. I would take a high clearance any day over a plane unless it is too wet. Planes charge a lot for a poor job.
 
#9 ·
The plane can sometimes be your best coverage due to vortices created with speed and downdraft. There have been studies done to support this.

Sounds like low water volume, but I wouldn't bet against the plane doing as good or better of a job than a ground rig with 5 times the water volume.
 
#11 ·
Ive watched the plane spray on a dead calm evening and you see some go down but theres also some that seems to hang in the air so thats what makes me question if its actually a good coverage? Would extra water be better? I would think with extra water then you are running higher pressure which would then create more fines or is that not how it works?
 
#15 · (Edited)
I think you definitely have to babysit them. I’ve sprayed fungicides during the day thinking man this is the last tank when the spray pattern looks like 80% was going up not down only to have a spray plane show up right beside me!!!

I have to legitimize my high clearance sprayer! :22: One aerial pass of everything would be $125K! One fricking pass.
 
#16 ·
The best job i have ever done with fungicide was with a sprayair boom at 4 gallons per acre. It got chemical on the top of the leaves, the bottom, the sprayer and the neighbors crop while it was at it. Did a better job than i do now at 10 gallons. I would still have it but the sprayer was a complete piece of junk and the drift was unmanageable.
 
#19 ·
Without testing out in the field, everyone thinks that their current setup is doing the best job. Put down some water sensitive paper in different configurations to mimic your targets (on the ground, taped to leaves, vertical wrapped around rebar for fhb, etc) and start changing variables to optimize the job.

It’s really no different than setting a combine or drill, some small changes really help out. One thing that was apparent is increasing water volume improved the job quality. I was happy with fungicides with 12.5gpa or more, 15gpa with diquat.
 
#20 ·
I'm curious what the per acre rates are you got quoted? $8-$9 p/acre will cover most acres here.

My brother is a cropduster, and my dad did it for 20 years or so. "Here" 5 gallons is the minimum rate, with a lot at 7 gallons, and occasionally 10 gals. A lot of trials have been done here over the years examining water rates for different chemistries. Long story shorter, a blind coverage test determined that 5 gpa actually had better fungicide coverage than 7 gpa. The nozzles on the planes are CP, which use a little different technology theory than ground rig nozzles. If applying phosphites on potatoes however, then the minimum is 7 gpa, anything less and leaf burn occurs. Once in awhile my brother will bring a plane from another region to help out if he gets behind in the summer, first question he asks is if the plane is capable of 7 gpa because most of the Midwest planes max out at 5 gpa, and 5 gpa with phosphites = upset farmer.

Cerone/Ethephon is a great shower of coverage patterns. Anything less than 5gpa shows significant streaking later in maturity. That's the same pattern your fungicide is going on with.

A few years ago a neighbor that has a history of contending with DON split a pivot. 1/2 with plane and 1/2 with ground rig. Plane was 5gpa and ground rig was 20gpa. Upon testing the grain, there was no statistical difference, but the plane side was slightly lower. Should note, the ground rig was NOT using forward/back nozzles.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top