40 BULLETIN 1032, U. S. DEPARTMENT OF AGRICULTURE. 
The spray gun, used in spraying McFarlin vines four times, gave 
the next highest yield, but the third highest percentage of uninfested 
fruit of this variety. 
The results of four applications with the Bordeaux type of nozzle 
on the McFarlin variety ranked third in yield and second in per- 
centage of uninfested McFarlin berries. 
Xo very definite conclusions based on yield can be drawn from the 
experiments of spraying on the Howe variety on account of injury by 
the fireworm on the plats in 1918 and frost in the spring of 1919. Of 
the Howe plats receiving three applications, however, the one sprayed 
with the Bordeaux type of nozzle resulted in the highest percentage 
of fruit free from fireworm injury, that sprayed with the mist type 
of nozzle was second, and that with the spray gun was third. 
Four applications with the spray gun on the Howe variety gave the 
highest percentage of uninfested fruit of all the plats on which the 
spray gun was used. 
Generally speaking, four applications gave better results than three. 
On bogs that can be reflowed, a complete covering of the vines with 
water for not less than 48 hours during the middle or latter part of 
May is recommended as a help in the control of the fireworm. Since 
most of the bogs on the Pacific coast, however, are managed as dry 
bogs, spraying with 40 per cent nicotine sulphate 1 to 800, with the 
addition of fish-oil soap at the rate of 2 pounds to every 50 gallons, 
is recommended as the most feasible method of control of the black- 
head fireworm in that locality. 
Between 250 and 300 gallons of this material should be used per 
acre. In making up the nicotine sulphate spray, the fish-oil soap 
should be mixed with about half the quantity of water and the re- 
quired amount of nicotine sulphate added with the remainder of the 
water to prevent the formation of a precipitate which decreases the 
effectiveness of the spray solution and which might also clog the 
nozzles and possibly injure the vines. This spray solution can be com- 
bined with Bordeaux mixture or lime-sulphur in the usual propor- 
tions, in which case the process of mixing is the same as though water 
were used. No soap, however, should be added if the mixture contains 
lime-sulphur. The large eddy-chamber type of nozzle, throwing a 
medium fine mist, at a pressure of about 200 pounds at the tank, should 
be used ; other types of nozzles may not only give unsatisfactory re- 
sults but may also injure the blossoms. The spray gun should be em- 
ployed only on lightly infested bogs. 
Vines which are lightly infested should have three applications of 
the nicotine sulphate spray, the first one when the new upright growth 
has reached a length of about three-fourths of an inch, the second 
when the blossoms are in the early " hook stage." and the third when 
the vines are in full bloom. 
