Spray-drift technique

Using this "spray-drift" technique, half-lives for triflura-lin conversion were measured (Table IV, 25). Under optimum sunlight conditions (August, 12 00 noon) the half-life for triflura-lin dealkylation was 21 minutes. The rate fell off later in the summer, but was still on the order of 3 hours in October. By comparison, laboratory photolysis in air containing ozone was 47 minutes, in reasonable agreement with the field. The rate was slower when no ozone was present in the reactor, and little or no reaction took place without light. 

P. C. H. Miller, P. J. Walklate, and C. J. Mawer, A comparison of spray drift collection techniques, in Proceedings of British Crop Protection Council Brighton Conference on Weeds , British Crop Protection Council, Farnham, pp. 669-676 (1989). 

In a recent summary report, the SDTF state that from their studies droplet size was the most important factor affecting spray drift. Their studies support the view that the physical properties of the spray mixture generally have a small effect relative to the combined effects of equipment parameters, application technique and the weather . 

A matter of considerable importance in the selection of an application method is its efficiency. Spray techniques are usually inefficient, since many droplets drift past the target and are lost. Even electrostatic spraying can waste as much as 35% of the paint. There is some loss of paint in most methods, but roller coating, curtain coating and electrodeposition are very efficient. Electrodeposition is also a very useful technique where corrosion resistance is important, since it applies a uniform coating over nearly all surfaces of even the most complex-shaped article. 

One problem that has arisen with the use of herbicides in agriculture is spray or vapor drift. When fine spray droplets are released, especially if applied aerially, they may be deposited beyond the target area due to air movements to cause damage there. In the first place, this is a question of application technique. Herbicides, like other pesticides, should not be applied as sprays under windy conditions. In most... 

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