Sprayers controlled droplet application

The use of pyrethrins in heavy (nonvolatile) oil films to control moths in stored products was practised prior to the discovery of synergists (Potter, 1938), typically using solutions of 1.3% pyrethrins. These have now been replaced by synergized formulations, which are more cosh effective, e.g. 0,3% pyrethrins + 3.0% PBO 0-25% bioresmethrin + 0.25%. PBO. Applications for this purpose are from mist, fog or UI.V sprayers adjusted to give a coarse droplet size (>80 pm) which provides a surface deposit on stacked commodities when applied at dosage levels equivalent to 4 mg synergized pyrethrins per m. ... 

Pesticides are substances that repel, kill or otherwise control unwanted animals or plants. Examples include insecticides, fungicides and herbicides. The formulation of pesticides is significant in terms of product stability and product performance. The current trend in crop protection is towards products that are more potent, safer to user, having less impact on the environment, more convenient to use and improved efficiency of the apphed product [85]. In the case of sprayed products, colloid and interface science impacts all aspects of apphcation. First, spray droplets impact the leaf surface, creating a fohar deposit from which the pesticide moves into the leaf or contacts the pest (see Figure 13.7) [85]. The spray pattern is influenced by the applicator nozzle hydrodynamics, the physical properties of the spray fluid and the movement of sprayer vehicle. 

---