Enhancing efficacy | Tackling Spray Water Challenges | Villa Crop Protection | Dr Brian de Villiers Unlisted

Are spray water conditions reducing your product performance without you realising it?

In this webinar, Dr Brian de Villiers, adjuvant expert, explains how water quality affects spray efficacy, from mixing in the tank to droplet drying on the leaf.

He unpacks key factors like cations, pH, buffering capacity and turbidity, and shows how they influence absorption, compatibility and overall control.
You’ll learn how to identify risks, adjust spray water correctly and use adjuvants to improve efficacy and protect your investment.

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Transcript

Well, good afternoon, everyone, and welcome to today's webinar on, enhancing the efficacy, by tackling spray water challenges in the tank. My name is Brian de Villiers, and I'm currently working as a consultant for, Villa Crop Protection. I've spent about 17 years full time, with the Villa team. Thank you for joining us today. I trust you will find this session insightful and valuable as we discuss how a spray water quality can impact product performance and efficacy. And, you know, just a special word of welcome to everyone that's tuned in today. Everyone from South Africa know the people from Zambia that have, on in the webinar as well. So welcome, welcome all of you. Just a few, house rules before we, start of, presentation. The first thing is, you'll see, I'll put off my, camera just as I start the presentation, if you don't mind. I'll put it on again. Once we do the conclusion right at the end. And then, just to think about questions, if you don't mind. If you have questions, I think it will be better. If we discuss the questions afterwards, you can phone me. They're my contact details. Or you can email me. And then we can discuss it in detail. So, yeah, we probably not going to have a question and answer session at the end of the webinar, but you're more than welcome. To contact me on, on that, cell phone number or on my, email address. And then another thing that I'd like to say before we even start the presentation, I'm going to show you a lot of photographs today of trials that we've done with adjuvants. And then your immediate response will probably be, but look how poor the control is. But I just want to explain that this is how we do adjuvant trials. If we want to see the differences between adjuvants, and we really want to determine the influence of water quality, we normally cut the rate of herbicides, especially, to show those differences. So you'll see in some of these slides that there's going to be very poor control. But draw the focus on the differences that we get there. Okay. Good. So, you know, they might contact details. Like I said, you're welcome to contact me at any time. Just a bit of content. About today's presentation. First of all, I'm going to give you a bit of background as to why water quality is so important. The the first the first step. And I think after I've showed you a few slides, you'll realize that water quality is probably one of the main factors when it comes to the efficacy of some products. And then just to show you, a bit about what, what Villa specifically does about water quality, how we warn, the end user about what has to be done about water quality. And then we're going to break up the the presentation into three or into four components. Basically. First of all, we're going to talk about Captain Antagonism. And when I talk about cation antagonism that's salt antagonism. It's also called that is basically the antagonism of especially certain post emerge herbicides. By antagonistic cations that are naturally dissolved, in water, like for instance, calcium, magnesium, sodium, potassium for instance. So that's what we're going to do under cation antagonism. So that's mainly about herbicides. Then we're going to do a whole section on pH. Why it's important why we use buffers. But also a few warnings about where a low pH sometimes caused by buffers but sometimes also caused by other components in the spray tank where these products going to have a really negative influence. We can talk about pH. We've spoken about buffering capacity now. Buffering capacity always goes. It's goes hand in hand with pH. Buffering capacity is the is the ability of water to resist a change in pH. So therefore you're using a buffer, for instance, you think that, that you decreasing the to a certain level, but because the water has a high buffering capacity, the pH doesn't go down as much as what you, suspected. It's not acidified enough. And then you have problems. On the other hand, very low buffering capacity allows the water to be acidified very easily. And then lastly, I think there's only one slide. About that, we're going to talk about turbidity of water. You know, frequency trouble like fun water that how the clay minerals, organic matter, that is suspended in water.

Okay. So let's begin and set a bit of a background as far as, water quality is concerned. If you look at various companies labels, but especially the value labels, in this case, you'll get a very good clue as to products that are sensitive to, some form of water quality. And I've got three of them that I'm going to show you today.

Now, why is water quality so important? And this is an important slide just to show you the magnitude of, the influence of water, and spray water on on the efficacy of products. We've got three phases that we've covered in the spraying process. First of all, we've got the spray solution phase, then we've got the spray droplet phase. And you'll, remember that the last webinar that done did was about this spray droplet phase. And then the last phase is the plant phase. Basically, what crop protection products and adjuvants do, in those three phases? Now let's just, just give a bit of explanation about each phase. If we look, first of all, at the light blue phase, the spray solution phase. So that's when, from when you mix your, crop protection product in the spray water, where they'd be in a mixing tank or the tank itself doesn't matter until the droplet has fully dried on the leaf surface. And this is where we often make a huge mistake. We think the spray solution phase is just in the tank. It's not just in the tank. It goes much further than that. It goes to on the on the leaf in the droplet. And a further reactions occur there as well. And if we realize that these reactions occur, we'll be even more careful, with these particular products. And then the spray droplet phase that you did the last time that, you guys, that that, tuned in last time to the webinar, the spray droplet phase is from when the droplet is released from the nozzle until it impacts the leaf, and then the plant phase is from when the droplet impacts the leaf till the process is completed, till all the herbicide or its systemic other products insecticide has been absorbed, or the contact action has been finished, etc. etc.. So so so that's the plant phase. But one thing that you can see there very, very clearly is that the spray solution phase, it encompasses the spray droplet phase of the spray droplet phase is encompassed in the spray solution phase, and a big part of the plant phase is also encompassed in the spray solution phase. And this is why the spray solution, and this is why, pH cations, the adjuvants that rectify them are so vitally important because it, it's such a, it's such a play, such a huge role in the whole, efficacy process that although I divided them into three phases, it's actually just one application process. And, and it's so intertwined, these different phases, that the one influences the other. So from when the product is mixed in the tank till the process is completed in the on the leaf is I call the application process even of, you know, some of these reactions happened long after the tractor has passed over the or the sprayer has passed over the, the crop. So water quality is important from mixing in the spray tank until the droplet has dried. And I'm going to emphasize that again until the droplet has dried. Because because this is this is where we often miss things. And we think that if everything mixes nicely in the spray tank, that it's going to be fine when it's it's on the leaf. And that's not always, the case.

So let's give you an example. So for instance, there's a grower, that applies this mixture. He's got three crop protection products that is mixed in the spray tank or in the spray water. He's got a foliar nutrient in there. He's got a buffer because one of the crop protection products recommended to buffer, for instance, he's got its effect. And for the same reason, there's a product that recommended a surfactant. And then he's used a product like interlock, for instance, which is a deposition agent. So it's basically got seven components in that spray tank. And I think all of you will agree that this often happens. This is a a thing that often happens, these type of mixtures are not uncommon, with the South African grower and we've seen more complicated mixtures than this. The important thing to remember, however, is as far as water quality is concerned, is dissolved and suspended particles in water do not disappear. So they present in that spray solution, but they will also be present later as the droplet dries on the leaf surface. And if I had to ask people how many, crop protection or how many components have we mixed into the spray solution or how many components are they in the spray solution? I think most of you will say seven three crop protection products and and four other products, but the answer is actually eight. Water, is another chemical in the spray tank? Water has a pH, water has dissolve cations and water has buffering capacity. And that all influences the efficacy of other products. Now, like I said, dissolved and suspended particles in water do not disappear once you've sprayed these the, the spray mixture and it lands on the leaf. Obviously the products are not separated. They, they, they, they, they, they do not lie apart. They are actually intermingled. So they all mixed together on the, on the leaf. And there is also cations. There's mud in some cases, organic matter, it's got a certain patch etcetera. And this is where further reactions occur because if you can, if you just think that water droplet is going to start evaporating on the, on the leaf and as it evaporates, the solubility of products is going to be, limited, and they're going to start reacting with each other. And if you're applying an antagonistic tank mixture or if you're applying a pure, spray water, then you're going to see, the, the effect of this.

Now when people get a spray water analysis report back from, from the lab, it's often extremely, intimidating. And you can see that's just an example of, analysis report that we got from bemlab. At that stage, it's two water sources on a growers form, for instance. You can see all the components there. It cetera. ET cetera. I just want to tell you that this is one of the water sources that I've seen that that had the most antagonistic, dissolved salts in the, so, so it was a pretty bad. Or both of them were pretty bad, but they just a few things that you need to look at for an, an analysis analysis like report like this. And then you'll see it's actually quite simple. It's quite simple. What you going to look for. And I'll give you a few, threshold values just now that can maybe help you a little bit. But let me show you what's important. The first thing that's important is your calcium. Magnesium, your sodium, your potassium and certain heavy metals. Metals like, iron, for instance. Heavy metals are normally not a big issue. But but the full, other cations, the calcium, magnesium, sodium, potassium. That's what makes what is hard if it's got a high calcium and magnesium content or it makes water brackish if it has a high sodium content, for instance. And those cations influence herbicides, for instance. If you don't, do a full water analysis report, you maybe just have easy or total dissolved solids as a single measurement. That's also a good indication of the amount, or the concentration of dissolved cations, in the water. So, for instance, if you ever have a look at the velocity driver max label, you'll see there that are there for us for in some cases now for a full water analysis or just an easy measurement to look, if you're right, is in line with what you should be. Applying EC, for instance, is not this accurate, to say exactly what cations are there, but it's a pretty good measurement as well.

The next one is pH. pH is a very important factor, but probably one of the most overstated factors and overrated factors as far as, crop protection products are, concerned. And, I'm very much, a believer in the, in the correct use of buffers to correct pH, under certain conditions and with certain products. But I think they're often overused, and I think they can cause problems. And, I don't want to stand still with buffers. I want to also say that other products that we are mixing into spray tanks, that also acidify the spray solution a huge amount, like for instance, overly acidifying foliar nutrients can also play a huge role. And I'm going to show you some some examples later on of what the problems can be. The only anion that is important is bicarbonate HCO3- and HCO3-, or bicarbonate and carbonates to a lesser extent, but normally carbonates are not present. As you can see in this water, it's mostly bicarbonate that works together with a pH. So therefore if you've got a high, for instance, this water is 7.6 or 7.5. If you can look at the back carbonate levels at 466 and 567, that's particularly high. So that means if you've got a 7.6, don't think that you're going to reduce the pH of this water very easily because of those high back carbonate levels, that gives it that buffering capacity and that resists change. In pH now a high buffering capacity can be a bad thing under certain conditions and maybe even a good thing under other conditions. And, if you stick around, I'll show you a bit later. Exactly. What the effect of buffering capacity is. And then the last one is turbidity. And I think this one is, it goes without saying, is the dirtier the water is, the higher the amount of clay minerals, the higher the amount of organic matter in that in that water, the bigger the problem is going to be. So, so clean, clean water is I suppose we can all argue about the definition of clean water, but surely we do not want muddy water or water with a high, organic matter content.

Okay, let's start with the first one. So we starting with the first one cation antagonism of herbicides by hard and brackish water. Then the next one will be pH buffering capacity and the last one will be turbidity. But let's let's start off with a cation antagonism. And it's probably the biggest part of today's, presentation. Now I've got a glyphosate slide there. And before I carry on, I'd like to say I've got a lot of glyphosate slides under this, heading today. But that doesn't mean that this site is the only herbicide that is influenced by cation antagonism. Many, many other herbicides are influenced as well. I'm just using larvicide because it has been researched so well, and that's where I had the most visual material. But other products like Clethodim, certain sulfonylureas, Phenoxy herbicides, some of the imidazolinones, the list continues. It's a long list of products posed emerging herbicides that are influenced by by cations in water, in spray water. But let's just have a look at this one. We've got three pots. The self-explanatory one, rate of glyphosate was applied over all three pots, exactly the same. rate. But you can see the difference in control, distilled water on the left at this particular rate, And like I told you in the beginning of the presentation, it was a pretty low rate because it was a glasshouse trial. But with this particular right, you could control, the weeds almost 100% when you applied with hard water that contained high amounts of calcium and magnesium, or brackish water that contains high amounts of sodium, you can see the difference in in control. So this is what water quality can do. And now the huge difference is here. You're not going to get these type of differences in the field. But I've seen differences of 10% 15%, 20 and 30% in the field. When glyphosate, for instance, was applied with poor quality water and nothing was done about the problem.

Okay. Let's talk a bit about glyphosate. And remember, when I talk glyphosate, we're talking all these other herbicides as well. That's just a, glyphosate molecule. What it looks like it's not important. Exactly. What it looks like, but what happens, with get a cation antagonism of herbicides. Does it happen in a spray tank? And the answer is no. Cation antagonism of herbicides does not happen while the product is soluble in the spray. And the reason for that is when everything is soluble in the spray tank. There's enough water to keep everything in solution. And there's no too little binding of cations, with a glyphosate molecule. But as the droplet dries out on the leaf you sprayed, now the droplets lying on the leaf, it's busy drying out. And you've sprayed, for instance, with a hard water, calcium water. But you can replace that calcium with magnesium or sodium or potassium as well as what happens to that glyphosate molecule on the leaf. And this is basically what happens. It it totally warps that glyphosate molecule, calcium because it's a divalent, a double positive charged cation or magnesium, have that effect on the side molecule. So the glyphosate molecule is totally being changed. And because it's being changed, it totally alters the the, the action of that particular, product. Now sodium will look a little bit different because sodium is only got one positive charge. But sodium is about 60% as antagonistic as calcium. So it's also vitally important and very important in South Africa because it's found in such large quantities. In certain areas. So I said, it all happens on the leaf I showed you. Now what happens to the molecule. Let's see how what it looks like in in practice on the leaf. So this is basically glyphosate sprayed droplets or sprayed droplet residues that have dried out on the leaf surface. So there's no more water in these spray droplet residuals. And then we took scanning electron micrographs. It's 500 times enlargements of a dried out droplet on the left. It was applied with distilled water. And the 59% is the amount of absorption, the percentage absorption of that glyphosate that we got when it was applied, in distilled water, as soon as it was applied in calcium, in high calcium water or high and hard water, you can see the, the the physical characteristics of that spray droplet residual residual changes, it becomes thick. It becomes a amorphous, it becomes it doesn't lie nicely in the walls of the of the plant, of the cell walls. And there's very poor contact and therefore you get very poor absorption. So 59% percent with distilled. What did we get with a high calcium water? 1%. Now, this like I said, this is a very extreme example once again, but that shows how devastating the effect of antagonistic cations in spray water can be.

But it doesn't happen in the tank. It happens on the leaf surface as their droplet, is drying out. Now, this next slide, I don't want to say you must take it with a pinch of salt, but these are just the guidelines that are used. This is not published data or anything. This is just what I believe. Often people ask us, but, you know. But what are the threshold values? How much calcium and magnesium or how much sodium is they be in the water before you've got a problem. And my answer is always, if you've got one part per million in there, you should already be using adjuvants. Because adjuvants have have a very positive effect, even in the absence of, of, of these, antagonistic salts and especially ammonium sulfate adjuvants. But if you want to use fresh thresholds, safe calcium and magnesium, that's how hot the water is, is above 100 parts per million. Then you can start having serious problems. All sodium plus potassium is above 100 parts per million. Same story, but they don't want to say it's an additive effect. So therefore, if you got 25 parts per million of calcium, which is very low in 25 of magnesium and 50 of sodium, then you've already got a problem. So so you don't need very high cation levels. Do you see the red lights flashing? And do us use adjuvants probably as a standard practice to overcome these problems. And then the next one is if the EC goes above 100 milli Siemens per meter, then you can start having serious problems. But like I said, take these threshold values. If this is really not data, not based on any data, it's just by experience. And this is what we've seen out in the field. And these are normally the threshold values that I work on. But one of those, proponents of, of using adjuvants as a standard practice when it comes to ammonium sulfate, especially.

Now the reason why ammonium sulfate is so effective, remember I showed you I'm going to show it to you. Now again on the right is the distilled one that was glyphosate alone in distilled water. And then you saw the one that had the calcium in the water. Now the one on the left on this slide is larvicide transferred water. That was the same as that to the one that that, with the calcium in. But we had ammonium sulfate in here. Now I can see two things in this spray droplet residual. The first thing, in the bottom corner or the bottom half of that spray droplet residual on the left, you can see star shaped crystals. Okay. And those star shaped crystals are calcium sulfate. So something tells me that the calcium has been precipitated at leaf level, and, and bound to the sulfate. And that is enabled for assay to spray droplet residual. The rest of that spray droplets, the residual to, to physically look very much the same as it was in distilled water, thereby increasing efficacy and in eliminating the effect of of cation antagonism. Now the chemical success story of ammonium sulfate. And you will realize from today's presentation, I am a fan of ammonium sulfate. Still, why does ammonium sulfate work so well? And when I talk about ammonium sulfate, I'm not talking about fertilizer or any other product that hasn't got an L-number. I'm talking about spray grade ammonium sulfate that has an L number. I'm not going to go too much further in that, but those are the products that I'm talking about. The chemicals story of ammonium sulfate is calcium. Instead of binding to the glyphosate, rather binds to the sulfate to form calcium sulfate, which is very insoluble. It's gypsum and that precipitates at leaf level. The same reactions happen for magnesium and sodium and potassium. I'm not going to go into too much detail, but it's important that these cations are precipitated before they can react with a site. And this is why ammonium sulfate works so well. It because it it handles all for those antagonistic cations. The next thing that I'd like to say it's a complete reaction. Okay, I'll get back to that. Just it's a non reversible reaction. And the same principle applies to those other cations like I said. So let's stand still at the at the complete reaction. And then non reversible reaction. What I mean with complete reaction. If you have used a high enough rate of an ammonium sulfate containing product, then you will then you will, neutralize all those antagonistic cations. It's a complete reaction. It's not it's non reversible. So that means once it's done it can't go back again. It's not like, chelating product for instance. That, that, that there's a balance. This is a non reversible reaction. And this is why it is so so important to us at villa. And then also I'm showing the glyphosate molecule again. And when you're using ammonium sulfate that enables the site to be absorbed in its most absorbable form which is that one. So what is the effect on weed control? Okay. So this is, these aren't weeds. Exactly that we sprang on, but it was test plants that were planted and we sprayed glyphosate over them. And, I think you'll see why we are such believers of ammonium sulfate containing product. So that was hard water. The first one was untreated, the second one, the middle one is hard water. And, with with glyphosate at a certain rate. And then exactly the same rate of glyphosate, but with an ammonium sulfate product. Now, this particular ammonium sulfate product didn't even have extra surfactant to anything in there. It was just ammonium sulfate. So this is what ammonium sulfate can do for you. And once again, not fertilizer grade ammonium sulfate a spray grade ammonium sulfate. So that's how effective, it is. So I'd like to make a statement. Vella only believes in ammonium sulfate based adjuvants to address cation antagonism with all our herbicides that are antagonized, by cations. We only believe in the ammonium sulfate based products. And they do products. A premium product Class Act NG, which is, which I'll go into a bit more detail later. And Velocity Drymax. Class Act NG has also got surfactant & humectant in there with velocity Drymax is just a dry, good quality ammonium sulfate product. So those are the only two adjuvants that we believe in. With this particular, with these particular herbicides.

Okay. Let's say use some data just like any other company. Would love to use other products. That, that, that are just as effective as ammonium sulfate. But that we can apply at, very low rate because then obviously the transport costs, things come in, which is very, very important these days. Etc., etc., etc.. And this is the reason that we, that we believe in ammonium sulfate. So this is a trial that we had done by the ARC, and it's the data of that particular trial. So it's percentage control on the left there. And you'll see glyphosate control was poor and I've explained that already to you. The downside the loan was green is the green, bar. And then those five red bars of velocity dry mix applied at different rates. And the one on the right was a, a low rate ammonium sulfate replacement product that we can call product X, for instance. Okay. So let's go through this. There were the we we have circled those three bars that is ammonium sulphate. So that those that's the registered right range of velocity Drymax. Just to give you and an indication so you can see it's head and shoulders, above the other product. But what I'd also like to show you is if we then applied reduced rates of velocity Drymax, unregistered rates, actually, which I wouldn't recommend to see how that compared with, with, with, an ammonium sulfate replacement product. And those are the two blue arrows, the left one velocity Drymax at 25g per 100ml. That's that's nothing. And I'll never, ever recommend it right like that. But that was more effective than the other product at 100g per 100l of water. Once again, a right that we would never recommend, it was even more effective than the other product at the same rate. We weren't happy with these results, so we decided to take it out to the field. But we didn't test just one. Replacement product there. We tested two ammonium sulfate replacement products. So it's a repeated field trial. So there were two trials done in different areas. On to the podium. And it was done by Curativo. So control on the left again, this is glyphosate the green bar Class Act NG in the yellow bar product X ammonium sulfate replacement product. The gray one and the pinkish one on the right was was a product Y. Why both of them at the recommended rates for that particular water quality. But we didn't want to discriminate against these products because, we felt that clause acting also has a surfactant and that you may contain the. So what we did is we added extra Villa 51 to these other products so that we could compare apples with apples. And I think the results speak for themselves, that there's a huge difference in control. And, and, and lastly, this is why are we sticking, to these ammonium sulfate products?

Okay. Just a little bit about multi-component AMS products. Often we get ammonium sulfate that is mixed with other components in the in the formulation. And it's a one product. Does it all. Class act NG for instance, is ammonium sulfate plus a full rate of surfactant. So it's as good as you playing a full rate of Villa 51 plus a full rate of humectant and which which reduces droplet drying or increases droplet drying time. That's normally what what we use if we want to use a surfactant all we use velocity Drymax and sometimes add Villa 51 to that. Please be careful if you are using products that are, multi-component adjuvants, make sure that they contain they don't just contain the ammonium sulphate, they must contain enough surfactant and if enough humectant in there, we must remember there's limited space in formulations, and it's important to know that all the components are enough for that. Glyphosate product or one of the others that we applied with. The last thing, the stance on acid in the formulation. Sometimes, people want acid in, in, adjuvant formulation for, especially for the left side. We don't believe in that at all. We believe that, buffers are normally not necessary with glyphosate, for instance, in many of these other herbicides and unless specifically recommended. So we decided rather to have sufficient ammonium sulfate in there without adding extra products that would take space in that formulation.

Okay. We spoken about hard water and brackish water. Soft water also has challenges. Often. We often think it's only high salt content water, but often soft water also has challenges. And this is one of the challenges of soft water is excessive foaming. So if you in an area or you find that a lot of your clients have excessive foaming, issues, it's probably because your water quality is so good that you, get these these foaming issues good. We've done the the cation antagonism and we nicely on time. I think, the next one is the pH that we're going to be talking about. 

Now pH is, is especially important for some insecticides because they are influenced by alkaline hydrolysis or the breakdown of insecticides in high water. But it's first important to know how the scale works. And the first thing that we should know is the scale is from 0 to 14. The lower the number, the more acidic, the higher the number, the more basic. And and if, for instance, you're using buffers or other products that decrease the spray solution pH just by one pH point from 7 to 6, for instance, what you are actually doing is you're increasing the acidity levels tenfold. If you are reducing the pH by three points from 7 to 4, what you're actually doing is you increasing the acidity level a thousandfold.

So that means this is why buffers are so effective to reduce alkaline losses. But this is also why, reducing products can also be devastated. Devastating. Sorry if they are not used correctly. So let us stand and show you on this. I said to you alkaline hydrolysis is the ability or is is the is the sorry the degradation of insecticides for instance, or some insecticides in water with a high pitch. So just to give you an example of how alkaline hydrolysis works, if we look at the alkaline hydrolysis of a product, say it's an insecticide with a half life of one hour, in the pesticide manual, we can normally see what the half life of these products are. But let's say let's let's look at the alkaline hydrolysis with this product. With a half life of one hour after one hour in the spray tank, 50% of that product has been degraded, is gone after two hours. Another 50% of that 50%. And so we can carry on three hours and four hours. So after, if this product has a half life of one hour at, certain spray water, if it lies in that tank for four hours, you're only going to have 6% of that product left. So this this is why alkaline natural is very important. And this is why the use of buffers is important. But please, this is an extreme example. Most products about all products are not this sensitive to alkaline hydrolysis. But I always say if you're just losing 5% of the product, that could be the difference between acceptable control and unacceptable control. So that's why it's important to use buffers.

However, there are some disadvantages of a low pH. And the first one is solubility. This was a sulfonylurea herbicide. Once again the spray droplet residuals are not going to explain too much. And the bottle on the left, the that was that the spray solution at the pH of seven. That's the spray droplet residual. What it looked like on the leaf surface. We got 73% control in this particular experiment, which was also not great. But that doesn't matter, Lazaro. They look at the differences when we decrease the pH to A of five. That's what the spray solution looked like. It was totally out of solution. The spray droplet residual looked very different, was grainy. It was there was a crusty deposit on there that's never going to be absorbed properly in any case. And we only got 56% control. So it could, a low pH, could limit the solubility of certain products, sulphonylureas is a prime example of that. But there may be some others as well. And it's important when using buffers and, but even more importantly when using products foliar nutrients for instance, or other products that are mixed in the spray tank that are very low in pH.

Watch out for this problem because it could influence the efficacy. Not only the efficacy could be influenced, but compatibility could also be influence. I'm talking about physical compatibility. Sometimes when we got a low pH and especially when we applying low water volumes. And, and you've got products in that spray tank that already sort of on the, on the border of, of solubility. And you decrease the pH too much. That is the main cause of incompatibility. I can tell you that the main cause of incompatibility in South Africa, in any case, is, is very low water volume. So you limit this the space for products to be solubilised, and the second one is to low pH. And often these two lower are not caused by buffers. They are caused by other products that we add to the spray solution that reduces the pH to much. I'm not going to say too much about this. This is Villa’s to, buffer products. The one on the left, probably the most well-known one COMMODOBUFF, which is, normal organic acid buffer with nothing else in the formulation. So it's got a full right of passage in there and AQUABUFF PLUS, which is, also got very good buffering capacity, but it has a limited amount of, of surfactant in there. And this is where I'd like to give a warning even about our, product. If you're using AQUABUFF PLUS in certain, fruit crops, for instance, where you need a very low rate of surfactant, it's fine. It will decrease the pH and will probably add, in some cases, sufficient surfactant. But this is not a product, for instance, that you can use on row crops and say, listen, yeah, I'm going to replace, a buffer and I'm going to replace a surfactant because the surfactant right in this product is, is quite low for our crops, especially.

Okay. I said we can talk about pH unless we talk about buffering capacity. And if I take you back to the beginning, we spoke about buffering capacity as the ability of water to resist a change in pH. And we said the main culprit, is the non cold by carbonate or h cac. So let me just explain this particular histogram on the left we got pH. So both products pH starts at just above eight. The blue bar. We got low by low by carbonate and low buffering capacity. The green bar, we got high buffering capacity. Say for instance, we using a buffer in both of these water sources. And this buffer is a bit iffy. It's it's, you know, we it's a bit suspect about bringing down the pH. Water quality and buffering capacity can exacerbate that, that problem with that particular buffer. And I'll explain that why if we look at the low, buffered buffered water, for instance, we add a certain right of that buffer in, it's going to work fine. It's going to bring down the pH of between 4 and 6, maybe around about five. But once the buffering capacity of that water is high, it's going to expose the limitations of that buffer. And we're going to get a pH that is too high. It doesn't come down enough. And we're going to get alkaline hydrolysis. Conversely, and exactly the same explanation as just now if we've got a buffer that we use, for instance, that is inclined to reduce the pH too much under certain conditions, this can happen. If we applied in the high buffered water, it could bring down the round about five. But with this suspect product this could happen. Same buffer, same right, different water sources. And then you can sit with a huge problem with in solubility of products and incompatibility issues in the highest degree. So please use a quality buffer that you know can handle about all water sources.

I'd like to show you an example. Once again, exactly the same as the previous slides. But what we've got now, okay. And there's dotted lines of the target, right, to which these buffers on their label so that they bring the pH down to. So what we did is we did tritration curves. So I'm going to show you, full amounts of these buffers that we added to the water, to see how much the pH would be reduced and if it would be reduced to the right. Right, to the right pH range, the water contained 150mg/l of bicarb and etc. so the medium buffered water. Okay, let's see what happened when we added 20ml per 100l of water. This was below the registered right range of both these products. 50 moles per 100l of water. And now we moving into the registered right ranges 60 moles per 100l of water and 100 moles per 100l of water. These are two products on the market. And you got totally different results with it. So it's important that the buffer you use, you use constantly. It must be a good quality buffer. And you must make sure that it does. Exactly. What you expect it to do.

Okay. We not we doing well with the time and we are nearing the end. The last, aspect that I'd like to talk about is turbidity of water in Afrikaans ‘troebelheid van water’. How dirty that water is, how muddy it is. The amount of, of, organic matter that's drifting around, in that water. So let's go for it. That is that is my best art, unfortunately. But that's supposed to be, a water source on the left. That that contains, a large amount of, clay particles and maybe some organic matter that's drifting around in that water. Now, we'll mix the stuff we can even do a compatibility test in a jar beforehand. And, we can see that everything mixes beautifully in this water. Even though it is a bit murky or muddy. And we believe then that everything is fine afterwards. And that's my problem with, with these short tests is, is we we that's as far as we go. We just look in the sprite tank. But what happens further, if you think a bit further about what could happen. Yeah. As the droplet hits the leaf surface, it dries, it spreads out, dries out on the leaf surface. And what you left with then, or what you could be left with in is mud at the bottom there. And the active ingredient lying on top. So that is what often happens with, with with murky water, with turbid water.

But I'd like to just give you, a bit of a warning as far as incompatible tank mixtures, like I said, the tank mixes are getting more and more, complex and the water volume is going lower and lower, etcetera, etcetera. You can imagine if a bit of mud in water can have that effect and could limit absorption of a systemic product or another product. You can imagine that if you applying, a tank mixture with products or antagonistic, at the relief level, what are they going to do to each other? And this is often what happens. We we do compatibility test beforehand in a jar, for instance. Everything mixes well, it looks very, everything looks fine, in the jar. But we never see what happens on the leaf. And this is where their actions occur. This is where cations antagonize herbicides. This is where murky water has an influence. This is often where we allow to lower pH as an influence on the solubility of of products. So just be aware of that. This is an unknown phase, an unseen phase that we can, that we often discount and forget about. But it's probably the most important face of products. A lot of crop protection products is on the leaf itself.

Good. I'm basically finished with my presentation. Just like to summarize. And the first thing is that I'd like to say is we often talk about good and bad quality water. And I think that's, that's a misperception or water quality has got challenges in here. Spray water has got challenges. So therefore if we are applying a glyphosate or, one of the other herbicides, in hard and brackish water, we're going to get poor herbicide efficacy because of poor absorption, into the plant if we apply soft water on the other end. Now, if you understand the the concept, soft water means low calcium and magnesium, but it kind of has high levels of sodium or it's got low levels of everything. Soft water is normally, the high foaming issue waters, soft waters in South Africa. Are they various places? But canal water, for instance, sometimes in the Western Cape, the Eastern Free State in the Midlands? Those are often soft water where as you go to, to, for instance, in the Western Cape, for instance, you go borrow, a dam, for instance, and then the water quality is ten times poorer. So I'm just talking about, canal water specifically. And then so both of them have got problems. Hard water waters got issues. Soft water is also got issues.

Then high pH is alkaline. hydrolysis of some insecticides could happen at a high pH. And probably some other issues as well that I haven't even mentioned today. But an unnaturally low pH could cause in solubility and incompatibility. And once again, I'd, I'd like to say it's not normally not the buffers that cause these issues. It could be it, it happens, but often it's other products that we are adding to spray mixtures that reduce the pH drastically. So 20, 30 years ago we could get away with these type of mixtures, because we were applying huge water volumes on row crops. So everything was the water was enough to keep everything in solution. But these days, with low or lower water volumes that are being used is becoming more and more of an issue, especially in row crop and boom sprayers specifically. And then the last one, turbidity, it doesn't it doesn't have advantages and disadvantages. It just has disadvantages. Dirty droplet residue residuals and poor efficacy. So, sometimes people say they don't have an, a choice about what water source to use have. Understand that. But but then unfortunately there's going to be a reduction in efficacy of certain products where that water.

The last slide, and just a bit of an advertisement before we end off is about, Villa’s or the Winfield United product. That's marketed by Villa, which is Class Act NG, is an, established name in the United States. So it's been around for a long time, but NG was basically one of the last formulations. And it stands for next generation. So it's a 4 in 1 adjuvant solution for spray mixtures. Now I'd like to say something about Class Act NG. It contains enough or a full right of ammonium sulfate to negate all that salt antagonism or cation antagonism, whatever you want to call it. It contains another ironic surfactant. It's not the same as Villa 51, it's another type of surfactant, but it contains a full rate of surfactant. So if you applying at the 1 to 2% right range, you getting enough surfactant, it's going to CornSorb technology, which is, high fructose, maize syrup extract. And that helps that spray droplets take a longer time to dry out on the leaf surface. And therefore you've got a longer absorption time. And then it's got an anti foaming agent as well. But with all these components it's got everything in there that is suitable for glyphosate. So so that's a premium product. But obviously as the premium product is not used the next product will be a Velocity Drymax. If and if surfactants are included then then you must talk to your, agronomist about that use.

And that's, almost at the end. Don't go yet because we've got a last slide after this, which is a competition. Thank you everyone, for listening today. I hope it was, was, insightful. I hope it was enjoyable to listen to. And, if you have any questions, you are more than welcome to email me, on that email address or on, you welcome to phone me as well, and I'll be happy to answer your questions. And we're going to end off, on this slide. So yeah. So thank you for joining today's webinar. Just let me put on my camera before I carry on. Okay. So thank you for joining today's webinar. We trust that this, session provided valuable insights, into overcoming spray water challenges to improve product efficacy and performance.

Now, you, please feel free to leave your comments, about the wind webinar in the comment section. It's always good to to hear from you. And also kindly scan the QR code. You'll see on the slide there's a QR code. And then you will be taken to, a bit of a competition. Three questions that you have to answer quickly and then submit. And then you can win. Very a very nice prize. From Villa. So please scan the QR code on the, on the screen now and then go into the competition. And then lastly, please, also look at for communication, coming your way over the next few days with a short question and answer activity, giving you the, opportunity to, to earn, CPD points. So, you know, so thank you, everyone. It was really a pleasure having all of you in this session today. And, Yeah, please phone me. If you need any more information or email me. Thank you so much. Okay. Brian. Doctor. Brian. donkey. Let's eat. Not this. But Brian thank you very much for the presentation. Well it was great to listen to what you have to say. You're welcome.