Dr. Ajay Sharda Discusses Sprayers

(Jim Shroyer) Good morning, folks. Welcome to That’s My Farm. I’m Jim Shroyer, your host, and we’re in luck because we’re going to be speaking to Dr. Ajay Sharda from the Department of Agricultural Engineering at K-State. We’re going to be talking about sprayers, and they’re not what they used to be. Stay tuned, we’ll be right back after these words from our sponsors.Closed Captioning Brought to you by Ag Promo Source. Together we grow. Learn more at agpromosource.com.

(Jim) Welcome back to That’s My Farm. I’m Jim Shroyer and Dr. Ajay Sharda is with us. Ajay, good to see you. Thanks for being on the show this morning. Let’s talk about sprayers. We got a little miniature one right here behind us for research purposes. Tell us a little bit about the evolution of sprayers, because like I said in the opening, they’re not like they used to be. (Dr. Ajay Sharda) No, they’re not, Jim. Thank you again for having me. Well, a lot has happened over the last 10, 15 years in terms of how the sprayers used to be. We used to have a very typical base system where we have a pump, we have a pressure regulator, we have a flow control, a manual on and off system. We have a boom and some nozzles put on that. Now, the goal was that I knew what speed I want to apply the product on. I know what pressure I’m going to maintain. (Jim) You hope. (Ajay) I hope, yes. That’s a very good point. We are going to talk about that all along this time frame. Then, I used to, I used to calibrate my sprayer in some fashion. I used to go out and apply product. Now if you notice, the premises, I want to maintain my speed all the time so that I can maintain my application pressure. It was important, because if I go over that speed or under that speed, I’ll be either over-applying or under-applying the product. (Jim) Because the pressure will be going up as you speed up, and the pressure will go down as you slow down. (Ajay) Absolutely. That was the base system. The thing was, a lot of studies were done in the past where people went out and checked how the sprayers were doing. How the end users were doing in terms of calibrating those sprayers and making use of the technology. A lot of that came out that the sprayers were not calibrated, wrong nozzles. They were not applying the product in terms of how it should be applied. A lot of over-application and under-application in terms of the way people used to drive on the farm. (Jim) Over-application, there are all sorts of things, over; under-applications and all sorts of things that could go wrong. You could kill the crop and the weeds too, or vice versa. You don’t kill the weeds and they do damage. (Ajay) Absolutely. That is the whole thing, we want to apply just the right amount of product for good efficacy, for good pest control, and not damage our crop. It has all signs of bearing. Jim, we’re talking about the cost of labor, making sure that we maintain straight paths. We did not have that technology at that time. I was just guessing that I’m not leaving any space unsprayed or overlapping too far, because I have to either come back, or I’m spending more time, fuel and chemical on the part which I have already sprayed. These were a lot of the things that used to happen in terms of the areas that were on the field, and we did not have a technology to control those system inaccuracies at that time. (Jim) Okay, Ajay, we’ve got to take a break right now. I know we’re going to talk some more about these things behind us here, so hang on there. (Ajay) Thank you. (Jim) Folks, we’ll be right back after these words from our sponsors. See you in a minute.

(Jim) Welcome back to That’s My Farm. I’m Jim Shroyer, and Dr. Ajay Sharda didn’t run off during the break and I see you guys didn’t either. Welcome back. Ajay, in the last segment, we were basically talking about a spray and pray type of a system. And in the evolutionary process, we’ve moved up a little bit. Now, take us to the next step. (Ajay) Well, Jim, the next step was an obvious one where people want a little bit more control in terms of how the sprayers used to function. A little bit more knowledge in terms of how they were using technology, and some more assistance when they’re using the technology in the field to be more productive and precise. If you talk about these two or three things, the whole thing started with having some rate control systems on the sprayers. Rate control system means it’s not a spray and pray system anymore. It means that you set your system up for a certain application rate to apply at a certain pressure, because we have to follow product label, and at a certain speed. Now, when I slow down or speed up to keep up my productivity and efficiencies of time and everything, my rate control system will help me to keep my application rate constant all the time. That means that if I slow down, it will ramp down the RPMs on the pump, so that I can still put out the amount of product going out of those nozzles to have an application rate, which I decided to put on. If I speed up, then I can ramp up my pump to put more product at the nozzle ends, so I can put the same amount of product needed for that kind of application. (Jim) And this system is called what? (Ajay) Rate control systems, so they were rate control systems. (Jim) Or a flow-based? (Ajay) These are flow-based, because as you very rightly pointed out, because I’m saying, “I’m ramping the amount of product flow rate in the system.” When that happens it means that I’m changing the flow based on speeding up or slowing down. We also started to see some guidance systems and all those tiers. Now, that was helping the growers in terms maintaining a straight path. I have lesser chances of doing stuff like over-application or leaving gaps on it. We also started to have a system called Automatic Section Control Technology on it. Which means that if I have sprayed that area before, or if I know that I do not want to spray that area, or if that spray area lies outside my boundary, then that system will automatically shut off. It keeps track of the areas that have been sprayed in the past, or I don’t want to, so I can reduce my double applications and save on chemical, save on fuel, labor, and other costs. This system starts to help growers to be much more efficient. They used to give at the very end, a very unique piece of information, which is called as applied data. (Jim) As applied data. (Ajay) As applied data, and those can be turned into maps, and I can see how I did in terms of my application rate. It greatly reduced the amounts of over and under-applications. Now, I can optimize on my productivity. I know the product application, and I was able to minimize my overlaps and misses as well. (Jim) That’s dollars and cents we’re talking about? (Ajay) Absolutely. (Jim) Not wasting or saving, so to speak. (Ajay) Yes, sir. Yes, because the chemical is costly. The chemical is potent, and we want to be very sure that we apply the product in the right manner. (Jim) Ajay, we got to take a break. (Ajay) Thank you. (Jim) Folks, we’ll be right back after these words from our sponsors.

(Jim) Welcome back to That’s My Farm. I’m Jim Shroyer, and Dr. Ajay Sharda is still with us. Thanks, Ajay. Ajay, there was a big jump to go from the flow-based system recently, or in the recent past. What are some of the problems though with that system? And that’s going to lead us into some more discussion of what’s going on now. But what are some of the problems? (Ajay) Well, I will not say the – (Jim) Or gaps? (Ajay) – Gaps. Yes, so where we were, if you’re using a flow-based control system, we still have to understand that the application pressure is really important. I’m going to keep pounding that idea of following the label because the label is the law. When you select a product, there’s a clear indication of which application pressure you want to apply. What should be your droplet size? What should be your speed? Speed is an irrelevant thing, because if you can maintain your droplet size and pressure, you can go slow or fast. When we’re talking about flow-based control systems, we talk about we are ramping up the amount of product flow rate in the system. Now, what that does is, that increases the pressure when I’m speeding up, and that decreases the pressure when I’m slowing down. And you’ll be amazed that people drive anywhere from 4 to 18, 20 miles per hour in the field. Your application pressures can be anywhere from 30, 35 to 85, 90 PSI. What does that do to the droplet size? (Jim) A wide range of droplet sizes. (Ajay) Exactly, so I did not have the kind of droplet size distribution I’m looking for, because when I slow down, I have lot more droplets which are bigger, but when I speed up, I have lot more droplets which are finer or smaller size. That increases the chances of drift. (Jim) Killing the neighbor’s tomatoes – (Ajay) Absolutely. (Jim) – that are a mile away. (Ajay) [Laughs] That’s true. When I’m on lower pressure, I don’t have the coverage I needed. When I’m higher, I have lot more driftables, so drift increases. My coverage goes down. My application goes down. I have chances of off-target application going on on my neighbor’s farms. (Jim Shroyer) Right, okay. (Ajay) These are some of the things which are getting more and more important in terms of farmers to be careful about. People can still keep using this technology, but they have to be mindful that they still have, they should be maintaining a tighter speed range, so that their application pressures are constant. Their droplet size distribution is what they need. They still need to do calibration, whether it’s calibration of nozzles, calibration of the flow meter. They have to select the right system parameters. They know how to program that. It can happen, if you want to maximize your productivity, maximize your time and profitability, maybe we need something different. (Jim) Okay, we’re going to take a break now Ajay, and then we’re going to talk about where we are now in those changes. Folks, we’ll be right back after these words from our sponsors.

(Jim) Welcome back to That’s My Farm. I’m Jim Shroyer; Dr. Ajay Sharda is with us. Ajay, we talked, we’ve been talking about the flow rate system basically. Now, there’s a newer system called the what? (Ajay): Pulse with Modulation. (Jim): Pulse with Modulation. Okay, PWM. (Ajay): PWM, yes. (Jim): Okay, that’s what we have here. (Ajay): That’s what we have here. We talked about flow-based systems, great systems; we still have a lot of those systems on the farm. They can work great, but if you understand how they work, and you understand their constraints in terms of making them to put to use in a right manner. Now, what we have is a lot of manufacturers, Be Driven, Top Gun, or Tee Jet, or Capstan, John Deere. All these people are moving to this pulse with modulation technology. What technology does is it modulates. Turn the nozzles on and off in a tiered fashion or individual nozzle parts. (Jim) I guess I’m old school. That just makes me scratch my head. How does that work, but you’re going to tell me. (Ajay) Yes, I will. Now, the thing is, we talked about putting the right amount of product along around the nozzle. What we do is, we have what we call as a cycle in a second. As you have mentioned the systems that are 10-hertz systems; John Deere system is a 30-hertz system. If you have 10-hertz system, there are 1,000 millisecond cycles. In each hundred millisecond cycle, the longer I stay on, the more product I can put out from this nozzle. That means if I am going faster – (Jim) You want that modulation to be on. (Ajay) – on for a longer duration. The time for which I keep the nozzles up open using the solenoid, is called duty cycle. (Jim) Duty cycle. (Ajay) Duty cycle. The faster I go, the longer duty cycle or the higher duty cycle I have. The slower I go, it’s conversely. Some of the advantages that we get are that this system is able to maintain constant pressure at all times. We modulate the flow. We are increasing or decreasing the flow by modulating means by changing the duty cycle. There is no ramping up of the pump RPM and getting the right flow in the system. All I have to do is change the duty cycle and start putting the new flow rate out of these nozzles as I speed up or slow down. (Jim) That would mean that each one of these nozzles is independent. (Ajay) Absolutely. (Jim) When you’re making that turn, the inside is slowing down, so the duty cycle is slower, and the outside is going faster. It opens up automatically. (Ajay) Absolutely. That’s a very good point. That is some of the advantages of having a technology that can control the flow on each individual nozzle, which is called turn compensation, contour farming. When we talk about the planting systems, is that I can change that duty cycle. I can still maintain my application pressure. I will have the same type of droplet size distribution, which is very important for coverage and or overlap at all times. (Jim) Ajay, we got to stop and take a break here. Folks, we’ll be right back after these words from our sponsors.

(Jim) Welcome back to That’s My Farm. I’m Jim Shroyer. Ajay, thanks for being with us in this last segment. Ajay, in that last segment, we were talking about the pulse system, the pulse with modulation system. On off, on off, all the time through the field. It just seems to me, can you see that? Can you see that thing? The nozzles going on and off? What does that look like? (Ajay) Well, Jim. We know what this is, we’re going to turn the sprayer on and now you can see that as the nozzles spray on and off, and the cylinders go on and off, and the way they turn on, you can actually see those things very fast happening. You cannot differentiate, but we can slow down that movement and you can see in a slow motion, and you can see the nozzles coming on and nozzles going off at a very rapid pace. That’s a beautiful thing to see. You can see in your monitor that my pressure is constant. You can also see on your monitor that your duty cycle goes up and down as you speed up, slow down. When we use the typical flow-based system, I cannot control the flow rate in each individual boom, because then I have to have individual flow control systems for each boom. Now, I only have a solenoid to change that flow rate, and that is, I’m not saying that is the problem of the chemical resistance, or ineffective weed control on headland, or turning, just because of that, but if you can have a system which can accurately apply product everywhere. (Jim) Where you wanted to at the right. (Ajay) Exactly. Especially, things happen. Things happen, because people say that we don’t know when we enter into headland, or when we exit headland, how our systems behave. Sometime it takes five, six, seven, 10 seconds to apply. These things can turn a little bit faster than that. Those are some of the big advantages in terms of what you want to do. Another thing is, that in flow-based systems that are boom controlled valves, and they are great as well. Now, we have individual nozzle control, which keeps my pressure intact. Just like my individual nozzle control in a flow-based system, these also hold my pressure all the time, because I am just turning the solenoid off. The moment I turn it on, it immediately catches up. Then when I close, it shuts off immediately. (Jim) What are we going to see in the future? (Ajay) Well, from my perspective, coverage, understanding coverage, understanding how my system is putting product on my crop is going to be of utmost importance, because chemicals are becoming costly. They are becoming more important. They are – (Jim) They’ll be potent. (Ajay) Exactly. I really want them to be on my field. If I’m spending money or for whatsoever, I don’t want them to leave my field onto somebody’s yard, or water bodies or soil. Understanding coverage, how good good or effective coverage I can get from my system is going to be very very critical. (Jim) Ajay, Thanks for taking the time showing us this little apparatus here. Appreciate it. Folks, thanks for being with us on this episode of That’s My Farm and don’t forget next week about this same time, we’ll have another one of That’s My Farm. See you then.

Closed Captioning Brought to you by Ag Promo Source. Together we grow. Learn more at agpromosource.com.

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