66 Agricultural Experiment Station^ Ithaca, N. Y. 



The best proof that the apple scab fimgiis is the immediate cause 

 of the greater part of the apple failures of western New York is 

 afforded by the fact that thorough spraying with Bordeaux mixture 

 is usually followed by a great increase in the productiveness of the 

 orchard ; and it may be said that the indifferent results which occa- 

 sionally follow the spray are equal proofs that tliere may be other 

 causes than the fungus for the failures. Much of the failure with 

 the Bordeaux mixture, however, is due to careless or hasty applica- 

 tion. If the Bordeaux mixture is properly made — using an excess 

 of lime — no injury may be expected to follow its use, and it 

 should be applied with great thoroughness. The operator should 

 endeavor to completely cover all the leaves and shoots. A mere 

 sprinkling, such as most persons give, is of little good. One 

 thorough application, which drenches the tree, is better than several 

 of this ordinary kind. Then people are always waiting for fair 

 weather. Now, it is in the rainy weather that the fungi spread 

 most seriously, and it is then that the spray is most needed. With 

 plenty of lime the mixture adheres well. Spray between the 

 showers, even when the trees are wet, if you can do no better. To 

 delay is to fail. It is better to spray in the rain than not to spray at all. 



There is abundant proof that two to four applications of Bordeaux 

 mixture are capable of keeping the fungus almost completely in 

 check. It is not known what value there is in an application befoi'e 

 the buds open, but it can do no harm, and it is probable that it is 

 very serviceable in most seasons. At the latest, spraying shoidd 

 begin as soon as the blossoms fall. Make the Bordeaux mixture 

 with 6 pounds of copper sulphate, 4 pounds (or more if the lime is 

 air-slacked) of lime and about 40 gallons of water. It is always 

 advisable to add Paris green for various insects — 1 pound to every 

 250 gallons of the mixture. Then take up your position near the tree 

 with a strong pump and apply the mixture until the tree is soused. 



Does the Bordeaux mixture kill the scab fungus, or simply keep 

 it off ? To test this matter, marked leaves and fruits were immersed, 

 upon the tree, in Bordeaux mixture on June 20, July 4, and July 

 26. All the leaves and fruits were badly attacked with the fungus 

 at the time of the first application. Without going into details, it 

 may be said that none of- the treated leaves recovered from the 

 attacks of the fungus, but most of them were in better condition 

 when growth had ceased, in August, than similar check leaves upon 

 the same shoots. Those which were so badly diseased when the 



