Bulletin 130


for the same protection, which makes the cost 50 cents an acre
more than spraying. But in order for spraying to be practical, a
good barrel spray-pump and water must be available. It is
usually difficult to drive Ihru a velvet bean field with a wagon,
altho in many cases the grower can leave a road every hundred
feet at planting time. The damage done by driving thru the vines
when they are running over the ground without support is not
as great as might be supposed. A week later it will hardly be
noticeable.
 FORMULAS FOR SPRAYING AND DUSTING
 Not more than twelve ounces of powdered lead arsenate (or
a pound and a half of the paste) to fifty gallons of water can be
safely used. Even with that small amount one should put a
pound and a half of quick-lime (or two quarts of fresh lime-sul-
phur solution) in the water and should keep the liquid well
agitated while spraying.
 For a spray we recommend:
 Lead arsenate, powder -----------.. ----------..12 ounces
 Quick-lime __------.---------------------------. 1 pounds
 Water .-------------------------..----------- 50 gallons
If the paste form of lead arsenate is used, take 24 ounces instead
of 12. This amount should suffice for nearly an acre.
 The dry arsenate when used as a dust should be mixed with
about four times its volume of air-slaked lime. A coarse burlap
bag is tied to each end of an eight-foot pole, and filled with the
mixture. A man on a mule then takes the pole with the bags
and rides across the field, dusting the plants by constantly jarring
the pole. At least fifteen pounds of the mixture (three pounds of
lead arsenate or zinc arsenite) should be applied to the acre.

 DUSTER MORE SATISFACTORY THAN BAGS
 A more even and satisfactory method of spreading the dust
 is by means of a "blower" or dusting machine.. Even a careful
 man using the bags and pole will cover scarcely more than half
 of the surface of the leaves and will get the dust too thick in
 places; our experience has been that with ordinary labor but
 little more than a third of the leaves are dusted. More time is
 required to cover the field with a dusting machine, but the added
 thoroness more than repays the added cost of labor. A careful
 man is able to do nearly as thoro work with the duster as he is
 with a spraying outfit and at a smaller cost.