Florida Agricultural Experiment Station


needs. It is important to select a machine that maintains a pres-
sure of 200 pounds when several nozzles are running. A machine
with plenty of pressure produces a mist and covers the plants
with a fine film.
 A spray machine equipped with a four- or five-horsepower gas-
oline engine for operating the pump will give good service, al-


Fig. 36. Efficient type of knapsack hand sprayer.


though there are certain objections to the use of an engine, since
it is often difficult to keep it in operating condition. More surface
of the plant will be covered when high pressure is maintained.
 Spray machines should be thoroughly cleaned immediately
after use. Do this by running several buckets of water through
the nozzles while the pump is operating. If this precaution is