Nicotine Dust for Truck-Crop Insects. 13 
tree-dusting hose can be used, and the dust blown out over con- 
siderable areas of the crop. This is sometimes desirable in crops 
grown in plots (see Fig. 10) or where the plants are so large that to 
drive down the rows would do considerable damage. This is also 
a good method of application for such plants as melons or cucumbers. 
A small power outfit with two discharge pipes, used successfully 
in controlling -an infestation of the melon aphis in a casaba field, is 
shown in Figure 4. It covers the field at a rate of 1 acre an hour, 
using from 50 to 75 pounds of dust. The feed can be regulated 
so that any amount per acre desired can be applied. The.machine 
should be elevated somewhat, preferably on a small wagon rather 
rg. 4.—Power-operatcd fan duster used with success in a badly infested melon field. 
than on a sled. This outfit. with engine. costs about $150, while the 
larger outfit is retailed at $350. 
The most satisfactory method of dust distribution from power out- 
fits for truck crops grown in rows is through a series of pipes, cov- 
ering six or eight rows at a time. For some crops the pipes are ad- 
justed to shoot directly down on the rows, a pipe to each row, while 
on others the pipes hang down between the rows close to the ground 
and discharge the dust at right angles, toward the rows on each side. 
‘The first type is best for plants where the infestation is in the upper 
leaves, or where it is necessary to drive the dust directly down into 
the plants, while the second type has been found most satisfactory 
where it is desirable to direct the dust toward the underside of the 
leaves. Such a machine will cover about 4 acres an hour. Figures 
