Bulletin 208, Cucumber Diseases in Florida


taken regularly, considerable time will be saved, as it will not be
necessary to spend a half day cleaning out the nozzles when the
machine is used again. If the spray material is allowed to remain
in the machine, it will dry and form flakes or cakes that will not
pass through the nozzles.
 A good traction-driven spray machine will often give good
 service, if it is given the proper attention and kept in good con-
 dition, oiled frequently and cleaned thoroughly.
 HAND SPRAYING: A large number of growers plant only
 small acreages of cucumbers and the purchase of power sprayers
 is out of the question. In such cases it is necessary to do the
 spraying with smaller sprayers the power of which is furnished
 by hand labor. An efficient sprayer for small acreages is a type
 of knapsack sprayer as shown in Fig. 36. The rod is easily
 handled and the leaves can be thoroughly sprayed.

 COPPER-LIME DUST
 The use of copper-lime dust is looked upon with much favor
by a large number of growers, principally because of the ease of
handling and the larger acreages that can be taken care of by a
single machine. The cost of material is considerably higher when
the same control is obtained as with home-made Bordeaux mix-
ture.
 In selecting a power duster give it the same considerations you
would a power sprayer both in operation and after the operations
are finished. There should be plenty of power, preferably fur-
nished by an engine rather than by traction. To obtain the best
results the dusting should always be done when the plants are
wet with dew or rain and when there is little or no wind. Dust
that contains 6 to 7 percent metallic copper should average 30
to 40 pounds per acre when the vines are covering two-thirds of
the ground. Younger plants require less dust per acre and older
plants more. The 80-20 (80 percent lime and 20 percent dehy-
drated copper sulphate) dust has proved most satisfactory. When
using power dusters two nozzles per row are very satisfactory.
They should be arranged so as to direct the dust on each side of
each row. Thus, on average dusters carrying eight nozzles four
rows can be dusted, provided they are not planted too far apart;
 HAND DUSTING: In smaller fields where the maintaining
and operating of power dusters is not practicable it is necessary
to use smaller dusters worked by hand. These dusters are very