SPRAY RIG CALIBRATION

Example: you want 10 gal/acre with twenty inch spaced nozzles.

20x10=200
200x.0244=4.88 ounces in 100 feet for 10 gallons an acre.

I hope this helps.

Wes

Secondly you should calibrate total gpm of all nozzels at various presure settings. Then calibrate your tractor speed in feet per min., and note your gear and rpm.

Those three factors along with width of boom will give your answer. These guys have the idea on calculations, they are just not being accurate enough in their systems. Accuracy or lack of it can save or destroy a crop, it can also save or cost you a lot of money.

But when it comes to "on the farm" calibration and mixing to follow what teejet has in their manual. You need a scale or a certified meter to get accurate spraying results each and every tank full. The charts are a starting point and will point you to nozzles that are or are not withing acceptable paramaters which will effect uniform coverage.

The markings on the poly tanks used in farming operation and the pressure gauges bought over the counter leave a LOT to be desired for accuracy.

The coverage per acre can be anything you want and you won't hurt the crop any one iota as long as you add the chemical to fit your application rate.

It's the CHEMICAL applied per acre that is important, not gallonage per acre applied. For effectiveness, total gallonage is important.

One thing to remember also, your speed will vary from one pass through the field to the next. Just by running 'in the wheel tracks' vs 'virgin ground' can and will throw your application rate off by as much as a gallon per acres due to the fact the radius of tire in relation to the ground changes.

rule of thumb is to use a half tank full of carrier when doing your field calibration. Reason I say carrier is if you use 28% nitrogen as your carrier, it has different properties than water does. The charts are for water, nothing else. Sitting on the yard in front of the shop is a starting point. Final calibration is done in the field under operating conditions.

When you talk with any chemical rep "off the record", anything within 10% is considered 100% as far application is concerned as long as you aren't overapplying. It's the state that will be tougher on the mixture rate than the chemical companies will be.

I've applied fert and chemical on over 100,000 acres commercial in the past. Both with tractor pull type sprayer and the big floaters.

The key is too know how well calibrated your tank markings are, and do your spraying accordingly. Remembering you are applying the chemical at a particular rate per acre and are using the carrier to get that job done. I've changed rates applying by as much as 4 gallons per acre from one tank to the next due to the fact of the chemical added to the mixture.

Do your figuring on the chemical sprayed per acre, not gallonage and you will have many fewer problems.

If you don't know the gallons per acre being applied there is no way of knowing how much chemical you applied. I really don't care if you wish to waste money, however we have some awfully good chemicals that have been banned due to cavalier attitudes such as yours.

You may not think accuracy is important, however with insecticides, fungicides and to a lesser degree with herbicides your products are being tested almost every shipment, for chemical content. Every day the wholesale and retail trade are monitoring who is being careful and who's not. If you are one of the guys not being careful, they are not going to run the risk of having your product on their shelf. I can tell you from running my own retail outlet, the consumer is getting very wise also. They are quite leary of that perfect carrot, cabbage or turnip. I had a lady tell me one day," If the root maggot was able to do some dammage, I can be quite sure an over application of chemical was not used."

We are getting chemicals on the market today, concentrated to point the rates of application are in ounces per acre. Materials costing $300. per quart. You may as well learn to be precise, as spraying is a precission job.

Oh i'm accurate, no doubt about it. I usually am within 1 pint over 300 acres spraying roundup at 32 oz per acre.

What i was trying to imply, that the calibration on the yard with the calibration meters is a start. That tells you if and when the nozzles are or not in calibration, and if your pressure gauge is accurate or not. The unit as a whole ie. ground speed, pump speed, etc has to be done in the field. There isn't a tractor around that has an accruate enough speedometer to just hit the field and go set according to the manual.

That's why I run a radar unit with my monitor. And utilize the auto feature to insure my application is correct (although I don't care to use it because if a nozzle plugs that is in my blind area, the rate application showing on my moniter doesn't alert me to that) at any speed, both ground and pump. The small time hobby farmer trying to cut costs doesn't have that luxury. He has to go by when the tank says he has 50 gallons in it, that is what he has to reference by.I have done checks on doing post emerge application and the rate will vary up to a gallon an acre following the planter tracks vs running in the "virgin row". To set the rpm of the tractor for a set speed due to calculations done on paper is where the faults and missapplications occur that you are referring to. Read any manual for any sprayer and the recommended procedure is to set it up with a half tank of water/carrier and preform the final calibration in the field under field conditions. Do a test for yourself, calibrate a ground speed unit on the road, then calibrate it in the field, you will find a difference in the numbers.

When we calibrated the floaters when I was in commercial apps. We would set them on the road to get a starting point, then do the final in the field with only fertilizer and/or water for a final cal. With the pumps calibrated to scaled weights, that is what we operated under. Big difference between tank markings and true amount. THEN we were ready to do chemical apps, and only then.

As far as accusing me to be part of the cause of the tighter restrictions, you are way off base. Because of the following.
1. You have not been around when I calibrate and apply. You are only going on a short description that I posted. BTW, i always spray at a 5% reduction of rate, based on my calibrated monitor, sprayer and speed unit so I assure myself a greater chance of NOT overapplication. I spray chemicals at the rate of 2/3 oz/acre that cost me in the range of 15-$20 per acre, so yes I do know what they are and aren't. Remember I was in the retail end of things myself.

2. If you reread my first post, you will notice that I mentioned I have varied my application rate by up to 4 gal/acre to achieve the correct chemical app.

3. 25 years ago when spraying was done as a hit and miss (monitors were rich farmers toys) is when the restrictions started coming into play. I was the first in my area to spend $1000 on one for my family's operation to assure accuracy of application. It was the mind set of those farmers such as my dad's (gew up in 30's to the 50's), it's close enough ...if some is good then more is better, that caused the restrictions to be implemented.

Maybe I wasn't clear enough in my first post, but what I hoped to get across was an emphasis on being aware of the CHEMICAL being applied on a per acre basis rather than just concentrating on the total application only. And to calibrate the unit according to measurements and pressures that consumer has to go by, not what a book says it should be. A poly tank with the molded gallonage is far from being acrruate measurement, but without a certified meter or scale, the consumer has only that to go by, so one calibrates accordingly to be as accurate as possible.

My rig is calibrated to the marking on the tank and the pressure gauge that I have on my unit. Maybe I'm putting out 22 gallons per acre instead of 20 when the carrier is accurately measure out, but that is of no consequence because I am only adding 2/3 oz per acre of chemical in that mix.

The rules in Eastern Canada came not so much from abuse or even agricultural use. 95% of the land down there is forested, and that forest is a very valuable cash crop. Of course the fact forestry uses aerial spraying they became the traget of every enviormental group going. About 40 years ago we first encountered the spruce bud worm. It hit New Brunswick 15 years before Nova Scotia. In New Brunswick they mounted a massive spray campaign and managed to keep the crop alive until harvesting and marketing. This program was not without contraversy. When the bud worm hit Nova Scotia in the 1970's the government would not allow the spraying. The result was a crop loss of prime spruce, that has been judged to be, at that date the largest crop loss (roadside value) in North American history. That includes all agricultural and forestry crops. There was enough forest product lost that it would have been a 40 year supply for the processing facilities in the province.

Then what to do with all this land, They allready had tracts of land growing second generation forest that regenerated in undesirable species. Next came forest management to control the undesireable species. This started of with controlling broad leaf deciduous species with the old stand by brushkiller. Of course, you guessed it every enviormentalist from here to kingdom come showed up arguing the use of brushkiller but using agent orange as used in Vietnam as their criteria. The chemical being used today for this purpose is Roundup.

The farmers found themselves caughup in this whole contraversy. You wouldn't believe how many people would stand up in public meeting argueing against the use of chemicals in forestry, yet they accepted that it was okay to use on their food supply. I have sat through public meetings of some of the most senceless arguing known to man.

It was actually the farmers that decided something had to be done. They actually decided to propose the licensing program to the government. Farm organizations decided to go with a plan that was tough. The government bogged down in all this contraversy jumped at the farmers plan, and quickly passed it into law. Since the farming community had the expertize they pretty well got to run the program. That my friend is precisely why it was made tough. They did put policing in place. I personally was never stopped by them, while spraying but I know people who have.

Somebody check my math!

You divide your square footage BY 43560 instead of into it.