May 20, 2011 – Water And Pesticides
QUESTION:
What is a water carrier agent?
ANSWER:
Most of our pesticide applications today are made by mixing some concentrate material with a large volume of water to dilute it to the concentration recommended for application. The water is now the "carrier" for that pesticide concentrate, so we refer to it as the water carrier.
Now, there are some things about plain old water that many pesticides do not like, and we should be aware of them. These are the pH of the water (is it acidic, alkaline, or neutral?), salt content, and mineral content, which also may equate to "hardness" of the water. There are materials we can add to a tank to correct these inherent conditions in the water so that the pesticide works better, and these additives are called "agents". They may be a buffer to correct the pH or something to "soften" the water to remove minerals such as calcium carbonate and calcium bicarbonate.
This is an area you should be aware of for the water you use in your region. Over time ground water tends to become alkaline due to leaching of minerals in the soil or leaching of organic breakdown products from the surface. In general highly alkaline water is not good for pesticides, and this was a particular problem back when we relied on organophosphate and carbamate insecticides. These molecules degraded pretty quickly in alkaline water in a process known simply as Alkaline Hydrolysis, and we could counter the effect by adding a buffer to bring the pH to a more acid level. Simply mixing these insecticides in a tank of water and then leaving it over the weekend could result in a significant loss of the actual pesticide active ingredient, so that on Monday morning when you finally used the tank mix it might no longer kill the bugs.
Hardness in water also can seriously affect pesticides by causing the minerals to bind with the pesticide molecules and fall out of solution as insoluble salts. This could result in a sludge at the bottom of the tank composed of the minerals in the water and the active ingredient that you thought was mixed properly in the tank solution. This is particularly a problem with some herbicides, including glyphosate and 2,4-D. This points out why just assuming you can fill your tank with water and add the pesticide concentrate may not always be good policy. You need to be aware of the chemical makeup of the water you use. Where I grew up and where I worked in pest management for a couple of years the water was commonly ground water, and it had an extremely high mineral content. If you didn't quickly dry your car after washing it you would have thought it had snowed on the car, from the layer of white mineral material left there once the water evaporated.
So, a water carrier agent is simply an additive mixed with your pesticide spray tank mixture to counteract some negative features in that water carrier that comes through the garden hose.
View past Ask Mr. Pest Control questions.
What is a water carrier agent?
ANSWER:
Most of our pesticide applications today are made by mixing some concentrate material with a large volume of water to dilute it to the concentration recommended for application. The water is now the "carrier" for that pesticide concentrate, so we refer to it as the water carrier.
Now, there are some things about plain old water that many pesticides do not like, and we should be aware of them. These are the pH of the water (is it acidic, alkaline, or neutral?), salt content, and mineral content, which also may equate to "hardness" of the water. There are materials we can add to a tank to correct these inherent conditions in the water so that the pesticide works better, and these additives are called "agents". They may be a buffer to correct the pH or something to "soften" the water to remove minerals such as calcium carbonate and calcium bicarbonate.
This is an area you should be aware of for the water you use in your region. Over time ground water tends to become alkaline due to leaching of minerals in the soil or leaching of organic breakdown products from the surface. In general highly alkaline water is not good for pesticides, and this was a particular problem back when we relied on organophosphate and carbamate insecticides. These molecules degraded pretty quickly in alkaline water in a process known simply as Alkaline Hydrolysis, and we could counter the effect by adding a buffer to bring the pH to a more acid level. Simply mixing these insecticides in a tank of water and then leaving it over the weekend could result in a significant loss of the actual pesticide active ingredient, so that on Monday morning when you finally used the tank mix it might no longer kill the bugs.
Hardness in water also can seriously affect pesticides by causing the minerals to bind with the pesticide molecules and fall out of solution as insoluble salts. This could result in a sludge at the bottom of the tank composed of the minerals in the water and the active ingredient that you thought was mixed properly in the tank solution. This is particularly a problem with some herbicides, including glyphosate and 2,4-D. This points out why just assuming you can fill your tank with water and add the pesticide concentrate may not always be good policy. You need to be aware of the chemical makeup of the water you use. Where I grew up and where I worked in pest management for a couple of years the water was commonly ground water, and it had an extremely high mineral content. If you didn't quickly dry your car after washing it you would have thought it had snowed on the car, from the layer of white mineral material left there once the water evaporated.
So, a water carrier agent is simply an additive mixed with your pesticide spray tank mixture to counteract some negative features in that water carrier that comes through the garden hose.
View past Ask Mr. Pest Control questions.
