No CrossRef data available.
Published online by Cambridge University Press: 04 July 2016
The history of the application of fungicides is one which shows a tendency to use ever decreasing quantities of spray liquid to the acre; the reason for this is obviously one of economics. The classification of various spray techniques is discussed with particular reference to the term ultra low volume. This may be defined briefly as the spraying of such extremely small volumes of liquid to the acre that it becomes impossible to use a simple aqueous medium as carrier. The reasons for this are given and the advantages of using special formulating agents noted.
The success of the low volume technique of spraying potatoes for the control of blight is illustrated with a series of blight progress curves, showing that 5 lb of copper oxy-chloride applied at 50 gpa gives identical results to a similar rate of copper at 2 gpa. Copper estimations made on leaf samples from the top, middle and bottom leaves of a potato crop sprayed at 100 gpa and 5 gpa respectively show that the mass distribution of copper is much more uniform in the high volume plots than in the low volume plots. However, the largest quantities of copper are found in the top layers of the plots sprayed at low volume.