280 REPORT OF THE HORTICULTURAL DEPARTMENT OF THE 
that the differences between the 3-3-50 and the 4-4-50 formulas, 
as regards apple scab, are so small that the one is practically as 
efficient as the other as a fungicide, while it is certain that the 
weaker solution will produce less bordeaux injury. I recommend, 
therefore, a thorough trial of the 3-3-50 formula. 
Excess of lime.— Investigations in the orchards of the State, 
information from other apple regions, and the season’s experi- 
ments prove conclusively that an excess of lime will not prevent 
bordeaux injury nor greatly lessen tt. Therefore, a formula con- 
taining no greater excess of lime-than one part to one part of cop- 
per sulphate is advised. 
Moderation in spraying.— Moderation in the quantity of bordeaux 
mixture applied is recommended. The experience of fruit growers 
is that, the more liquid they apply, the greater the injury. From 
theory, such a result can be assumed. Power sprayers, now to be 
found in nearly every commercial apple orchard, are partly ac- 
countable for the great increase in bordeaux injury. Spray to 
cover the foliage and fruit with a thin film and yet not have the 
trees drip heavily. 
The modern nozzle, which breaks the stream into a fine spray, 
thus bringing the particles of copper salts in contact with a greater 
percentage of the leaf surface and exposing them to a greater 
degree to the solvent action of moisture, is a factor in bordeaux 
injury. But the fine spray for these same reasons increases the 
fungicidal value of bordeaux mixture and it is not therefore ac- 
visable to discontinue the use of nozzles which produce such a 
spray. 
Weather and spraying.—In the past it has been the custom to 
spray, rain or shine. These investigations show plainly that spray- 
ing in rainy, foggy, damp weather favors the production of 
bordeaux injury. So far as possible the bordeaux mixture should 
be used only in dry weather.. A slightly greater excess of lime 
may be used in wet weather than in dry weather. Since May is 
wet and June is comparatively dry, the time of spraying, whether 
early or late, may modify practice as to the use of lime. I doubt 
if the danger is great to fruit or foliage of the apple from bordeaux 
mixture in this State after July. 
In conclusion.— Bordeaux mixture is still the best fungicide. 
Spray injury is a serious matter, but apple scab is worse. No 
fruit grower can afford to give up the use of bordeaux mixture m. 
fighting apple scab. It is to be feared that because of the very 
