Agrochemical sprays

Uses Emulsifier for citrus and other agrochemical spray oil systems Properties Liq. HLB 9.0 100% cone. 

Accurate and even application of test substance is absolutely critical to study success. If the application is highly variable or deviates significantly from the target application rate, the study results may be technically unusable and/or unacceptable to regulatory authorities. Accurate agrochemical application begins with careful calibration of the spray equipment. Hence Study Directors should be familiar with sprayer calibration techniques, even if they will not be personally making the applications. 

Spray nozzle type plays an important role in the success of agrochemical application. For broadcast applications to soil, flat fan nozzles should be used. Newer spray tips such as the DG TeeJet, XR TeeJet, Turbo TeeJet and similar nozzles supplied by Lechler and Hardy have provided acceptable results in a number of studies. For a given nozzle type, the lower the application pressure, the larger is the spray droplet size and the less potential for spray drift. Similarly, the closer the boom is positioned to the soil surface, the less is the potential for spray drift." Most applications are made with spray tips having 80° or 110° spray angles and boom heights of about 50 cm above the soil surface. 

A combination of techniques is typically used to verify the accuracy and precision of agrochemical applications to soil. For example, the catch-back method or passtime method is typically used in conjunction with analytical results from application verification monitors to confirm proper application. The catch-back method involves measuring the spray solution volume before and after application to double check that the desired volume of test solution was actually applied to the test plots. Experienced applicators are often able to apply within 2% of the targeted spray volume. 

MAFF/Joint Medical Panel of the Scientific Subcommittee on Pesticides of the Ministry of Agriculture, Fisheries, and Food and the Toxicology Committee of the British Agrochemical Association (1986/1992) Estimation of Exposure and Absorption of Pesticides by Spraying Operators, MAFF, Pesticides Registration Department, Harpenden Laboratory, Harpenden, Herts, England. 

Surfactants are often used in agrochemical formulations as adjuvants, e.g. as wetting agents to improve the physico-chemical characteristics of the solution and to increase the uptake of active ingredients (e.g. pesticides) [6-8]. The surfactants can be included in pesticide products and/or added to the tank mix prior to use however, they rarely exceed 1% of the total applied spray. Examples of typical surfactants used in agrochemical formulations are shown in Table 2.8.3 [9]. 

The use of organosilicone surfactants in agrochemical formulations has become increasingly widespread [13]. These products are known to enhance spray coverage and in many cases increase the foliar uptake of... 

As mentioned earlier, surfactants have the ability to reduce the surface tension of water, thereby enabling spray solutions to more effectively wet waxy leaf surfaces and increase the amount of spray retained on the leaf. As a result, surfactants can make spray applications more effective by improving the deUvery of agrochemicals. 

Some agrochemicals are formulated as emulsifiable concentrates. Here active ingredients that are not very soluble in water are dissolved in a solvent that is, in turn, emulsified into the aqueous phase, either in the concentrate itself (an emulsion concentrate) or else upon dilution in the spray tank [865]. Some emulsion concentrates are designed so that when water is added to them they spontaneously emulsify to form an O/W microemulsion [225],... 

Exposure to infection, agrochemicals and pesticides samplers to be advised of dangers on training day avoid contaminated sites or fields being sprayed observe agricultural exclusion notices when encountered in the field... 

IMP (1986). UK Predictive Exposure Model (POEM) Estimation of Exposure and Absorption of Pesticides by Spray Operators, UK Scientific Sub-committee on Pesticides and British Agrochemical Association Joint Medical Panel, Pesticides Safety Directorate, York, UK. 

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