48 STATE POMOLOGICAL SOCIETY, 



ment by all men who look to their fruit for an important source 

 of their revenue from the land, — and rightly so. For every 

 year has shown them that spraying properly done means health- 

 ier trees, cleaner and better fruit, and, in consequence, better 

 returns. 



Spraying in its extension has also brought with it problems 

 for solution. For many years bordeaux mixture has been the 

 standard fungicide for orchard spraying, with Paris green or 

 arsenate of lead used in combination with it as the insecticide. 

 Paris green has in recent years been largely superseded by arse- 

 nate of lead, because the former has a great tendency to burn 

 and injure foliage, whereas lead arsenate has been found 

 equally effective in destroying leaf-eating insects without the 

 injurious effects upon the leaves. 



The increasing use of bordeaux mixture has, however, been 

 accompanied by reports of injury to fruit and foliage. Such 

 injury appears to vary in degree and in different seasons. On 

 the peach and Japanese plum it has long been known that bor- 

 deaux cannot be used with safety when the tree is in leaf. On 

 the apple and pear the injuries have manifested themselves in 

 two ways — burning or spotting of the leaves and russeting or 

 corking of the fruit. The leaves so affected show dead brown 

 spots similar in general appearance to some fungus leaf spots, 

 generally circular or roundish, but often irregular. Frequently 

 the areas are large, as though a number of smaller ones had 

 united. Occasionally the margins of the leaves show the char- 

 acteristic dead blackened areas. Such foliage injury is very 

 frequently followed later in the season by yellowing and pre- 

 mature leaf fall. This occurs early or late in the growing 

 season according to the severity of the injury. Sometimes it 

 does not occur at all. Whether such yellowing is actually the 

 result of bordeaux spraying is a mooted point among investi- 

 gators, but it is an acknowledged fact that it is a frequent ac- 

 companiment of leaf injury from this source. 



On the fruit the injury is first seen as small, dark, fly-speck 

 like spots. These are not to be confused with scab spots. The 

 former arc regular, smaller and not sunken. The final appear- 

 ance of the injured fruit is well known to most of you. The 

 skin is washed with a rusty or russet colored coat which ma- 

 terially detracts from its appearance. In more severe cases 



