22 BTT.T.F.TTX S66. "C. S. PEPAETMEXT OE AGEICULTUBE. 
ering sprays did not materially influence their adhesive properties on 
potato leaves. Xo injury to the leaves or to the potato plants was 
caused by any of the Pickering sprays tested. 
The amount of copper sulphate essential for the control of late 
blight on potatoes in Maine may be reduced 44 per cent by the use of 
Pickering sprays. The amount of lime required is reduced also and 
all grit removed from the spray, while at the same time the wear and 
tear on spray machinery is greatly diminished. These results were 
obtained in Maine where the principal potato trouble is late blight. 
It is impossible to state what the efficacy of Pickering sprays on 
potatoes would be in sections where other troubles predominate. 
BARIUM- WATER SPRAYS. 
Tests with a barium-water spray containing 0.7 per cent of copper 
sulphate showed that it gave practically the same control of late blight 
and the same yields as Bordeaux, 5-5-50. In fact, in 1917 and 191S 
the yields were slightly larger on plats sprayed with barium water 
than on those sprayed with Bordeaux. 
REDVCED-MILK-OF-LIME SPRAYS. 
The 3-li-5o spray tried in 1917 (a severe blight year) gave a 
larger yield and a lower blight reading than the 3-3-50 spray. In 
191$, the blight readings for the plats where the 4-1-50 spray was 
employed were a little higher than for those where the 4-4-50 spray 
was used. Apparently the amount of lime present in a Bordeaux 
spray used for potatoes in Maine has little effect on the fungicidal 
power. As long as sufficient lime is present to combine with the cop- 
per, the extra lime has no fungicidal advantage, but has several dis- 
advantages. 
Less copper adhered to the leaves when a 4-1-50 spray was em- 
ployed than when 4-4-50 and 4-2-50 sprays were used. This may 
be explained by the presence of free copper sulphate in the 4-1-50 
sprays. 
STANDARD BORDEAUX SPRAYS. 
In sections where the blight may be severe, such as northern 
Maine, a Bordeaux. 5-5-50. is recommended. In other States where 
the blight is usually less severe a Bordeaux. 4-4-50, is desirable. 
GRAPES. 
Control op Fungous Diseases. 
in new jersey. 
Four acres of Concord grapes near Vineland, X. J., were treated 
witli Pickering (A) and (C) sprays, varying in copper sulphate con- 
tent from 0.065 to 0.64 per cent, and with a standard Bordeaux, 
