 I'm Chip East and I'm here with Edgar Vinson and David Lawrence. We're with the Alabama Cooperative Extension System and today we're going to discuss backpack sprayer calibration. There are several methods that can be used to calibrate handgun sprayers. In this example we will be using the 1 1 28th acre method. This method can be used to calibrate a backpack sprayer powered by a hand pump an ATV sprayer powered by an electric pump or a large sprayer powered by a tractor's PTO. First you will need to check and clean the sprayer to make sure it's working properly. Then measure 340 square feet and with only watering the tank spray the 340 square feet at the same speed and pressure as you would if you were applying pesticide. Keep a record of how long it takes to spray this area. You may be best to spray this area several times and get an average. Next, while keeping the pressure the same, collect water from the handgun into a measuring cup for the amount of time it took to spray the 340 square feet. The number of ounces collected is the gallons of water per acre the sprayer is applying. If you would like to apply more or less water per acre an applicator can speed up slow down change tips or change pressure. Whenever a change is made the applicator will need to recalibrate the sprayer to find out exactly how many gallons of water per acre is being applied. In this example it took 70 seconds to spray 340 square feet. The farmer collected water for 70 seconds into a container and that was found to be 28 ounces. Therefore the farmer was applying 28 gallons of water per acre. With a four gallon sprayer the farmer is covering 0.142 acres with every tank full. If a farmer wants to apply 16 ounces of a pesticide per acre and treating 0.142 acres with every four gallon tank the farmer should add 2.3 ounces of pesticide per four gallon tank. There are several different methods for calibrating a backpack sprayer or a handgun sprayer. This method today is the 128 acre method for this method we measure off 340 square feet and that can be done in different ways. In this example it's 18 and a half feet by 18 and a half feet. We have that marked off to spray that known area. Then we're going to collect spray for that amount of time. Every how many ounces of spray we collect and in this case we're just going to use water. Every how many ounces of water we collect in that amount of time is how many gallons we're putting out per acre and that's all we're trying to figure out is how many gallons of water we're trying to apply per acre. It took a minute and 10 seconds to cover this 340 square feet with the backpack sprayer so now we're going to collect water into a measuring cup for that amount of time for a minute and 10 seconds. Every how many ounces we collect is how many gallons of water per acre this backpack was applying. When we calibrated the sprayer we this was found it was applying 28 gallons of water per acre. We have a four gallon tank so I take four divided by 28 I get 0.142 so I'm spraying 0.142 acres every time we fill that tank up. If you're applying pesticide at a pipe per acre I would take 16 or 16 ounces in a pipe multiply 16 times 0.142 the amount of acres that is sprayed with each tank full the amount came out to be 2.28 so if I say 2.28 or 2.3 I put 2.3 ounces of a pesticide in this tank every time I fill the tank and I'll be applying to create them out. Air blast sprayers are commonly used in tree fruit production and vineyards. Matthew Price is going to show us how to calibrate them. Hi I'm Matthew Price the director here at the Chilt Research Extension Center and we're going to look at calibrating air blast sprayers and the first thing that you need to know is you need to know the speed that you're going to be traveling and you're going to need to know your row spacing that's going to determine how many minutes it takes for you to cover one acre. Now some things that you need to know is when it comes to speed the slower you go the better coverage that you're going to have in your orchard it gives it more time turning the leaves and drives the spray up into the trees. So a rule of thumb that we use is we're going to set it at two miles an hour is what we're going to be traveling and a constant of that and setting your speed on your tractor is two miles an hour is 44 feet and 15 seconds. So if you can mark off 44 feet and take a timer and select a gear and your rpms drive at 44 feet and 15 seconds you'll be set. Now the next thing you need to figure is your row spacing how many feet do you have to drive per acre let's say you have 20 foot rows okay so you want to take 43,560 that's how many square foot an acre and divide it by 20 you'll wind up with 2,178 feet that you're going to have to drive okay and then as we're going two miles an hour we'll be traveling 176 feet a minute. So it's going to take us 12.375 minutes to cover that one acre. Now after you have all that figured out and your tractors rpms and gears figured out then you're going to need to know how much water you're putting out per minute. Now there's two ways to do this and the one method we have set up right here with these tubes is we have tubes on each nozzle on this side of this sprayer. Now this has been precult yesterday and we figured out that we're putting out five gallons a minute and this is just two slits over the nozzles and we'll catch it in the bucket and then we measure it after a minute so we found out we're putting out five gallons a minute on this side and the other side is putting out five gallons a minute as well. So that's 10 gallons a minute so we want to multiply that times our 12.375 and that gives us 123.75 gallons per acre that we will be applying. Now the other method to find out what you have to have a water meter with is you can mark a spot on your tank and you can back it out and set your tractor on the desired rpms for your speed and run it for a minute that way with both uh booms going and after you run in a minute you just take your water meter over here and you run the water in it until your level comes back up to your mark and tells you how many gallons you put out in that minute. So there's two methods that you can use to figure out how much water your sprayer is putting out per minute. There are several methods that can be used to calibrate a booms sprayer. In this example we will be using the one 128th acre method. First you will need to check and clean the sprayer to make sure it's working properly. This includes cleaning the tips. Turn on the sprayer and collect water from every tip. Make sure they are applying an equal amount. Then measure the distance in inches between nozzles on the boom. Use this chart to determine the length of the calibration course. If the nozzles on the boom are spaced 18 inches apart the calibration course will be 227 feet. The length of the calibration course is determined by how many feet you will have to travel for one spray nozzle to cover 340 square feet. To determine the length of the calibration course for a nozzle spacing not on the chart simply divide 340 by the nozzle spacing expressed in feet. A 19 inch nozzle spacing is 1.58 feet. Divide 340 by 1.58 to get the calibration course of 215 feet. Once you determine the calibration course measure that distance and put some type of marker at each end. Then drive the calibration course and record how long it takes. Use the same gear and RPM that will be used when applying pesticides. While the sprayer is stationary and with only water in the tank collect water from one nozzle for the length of time it took to drive the calibration course. The tractor should be operating at the same RPM when collecting water as it was while driving the calibration course. Measure the volume of water caught in ounces. The number of ounces equals the gallons of water being applied per acre. Adjust the pressure, speed or nozzle size to achieve the desired volume per acre. If the speed is changed you will need to drive the calibration course again and repeat the process. When a change is made to the nozzles or pressure you will need to collect spray in a container to check the gallons per acre again. In this example nozzles are spaced 20 inches apart and needs a 204 foot long calibration course. While driving the calibration course in the same gear and at the same RPM that will be used while spraying we find that it takes an average of 26 seconds. With only water in the tank the farmer stops the tractor and sets the RPM the same as in the calibration course and turns on the sprayer. The farmer collects water from one nozzle for 26 seconds and the volume of water caught is found to be 16 ounces. Therefore the farmer is applying 16 gallons of water per acre. If the farmer is applying 16 gallons of water per acre and has a 150 gallon tank then he can spray 9.4 acres with one full tank. If the label recommends one quart of pesticide per acre then the farmer will add 9.4 quarts of pesticide to every full tank. When calibrating a boom sprayer we need to just put water in the tank and turn on the PTO and collect spray from every nozzle. They need to be within 10% of one another. Once you do that we need to measure the distance in inches between nozzles on the boom. These are found to be 20 inches apart. The calibration distance for the one 28th acre method is 204 feet for nozzle spaced 20 inches apart. So we measure off 204 feet, drive that distance at the same gear and RPM that you'll be spraying and time yourself. In this example that we were found to be doing 26 seconds is how long it took to drive that 204 feet. So with just water in the tank we collect spray from one nozzle on the boom for 26 seconds. That was found to be 16 ounces. So this at that speed at that RPM at that gear we found that we're putting out 16 gallons of water per acre. So if you're putting a quart of a product of pesticide per acre for every 16 gallons you put in that tank you put in a quart of pesticide.