Limit losses with adjuvants

For crop protection products (CPPs) to be effective, a sufficient amount of the active ingredient must reach the site of action.?Unfortunately, from the time when the CPP is added to the spray tank, it is subjected to losses in every phase of the application process.?In the spray solution phase, cations antagonize various herbicides, while some insecticides are degraded by alkaline water.?Once the spray droplets have been released by the nozzle, more product is lost through drift, evaporation, and poor deposition.?The remaining CPP that does reach the target is then prone to droplet bounce and poor absorption due to the waxy layers on the leaf. It is remarkable that CPPs are effective, despite these losses.?Correct adjuvant use limits CPP loss in all phases of the application process.?This will ensure that more active ingredient reaches the target and that weed, disease and insect control will be increased.

Spray solution modifiers

Of the six major groups of adjuvants, three are used to modify the spray solution.?These are the buffers, the salt adjuvants, and the deposition agents.?The spray solution phase is important because CPPs are contained in water from when they are mixed in the spray solution, until the droplet dries out on the leaf.?Water contains antagonistic cations that reduce the activity of herbicides such as glyphosate, clethodim and various other products.?Fortunately, ammonium sulphate adjuvants are effective to neutralise all the major antagonistic cations.?Most water sources have an alkaline pH that will accelerate the hydrolysis of some insecticides. Therefore, buffers are used to reduce the pH and to extend the lifespan of insecticides in spray water. Deposition agents reduce the percentage of ultra-fine spray droplets.?This limits drift and evaporation, while increasing deposition and canopy penetration.

Efficacy enhancing adjuvants

Although all adjuvants are used to increase efficacy, the surfactants, oils, and stickers are classified as efficacy enhancing products. The reason for this is because these three adjuvant groups are active on the leaf surface. Surfactants and oils reduce droplet bounce, while increasing spreading of spray droplets.?They also play an active role to increase absorption across the waxy layers of the leaf. These layers can be particularly thick and difficult to penetrate under low humidity conditions. Stickers extend the action of certain contact fungicides and insecticides when required.?Although these three adjuvant groups are known as the efficacy enhancing products, other adjuvants, such as ammonium sulphate, also play an active role in the absorption process.

Villa’s stance

When using label recommended adjuvants, less CPP will be lost, and a sufficient quantity of active ingredient should reach the site of action.?Adjuvants reduce the loss of CPP through the entire application process and are vital components of effective tank mixtures.? Contact your Villa agronomist for more information about adjuvants and water quality.