BLOTCH 167 



or twice thereafter at intervals of two to four weeks. The 

 relative importance of these sprayings will vary with the season. 

 If the weather is dry during the early part of the season and wet 

 at the last part, a single late spraying may give better results 

 than two or three early ones. 



Rust. Similar forms of this disease attack the apple, pear 

 and quince. It is one of those peculiar diseases which at one 

 stage lives on one host plant and at another stage on another 

 host. In this case the second host, with all three forms of the 

 disease, is the cedar tree. On this it forms the peculiar rough 

 brown knots known as " cedar-apples, " and authorities agree 

 (and common experience bears them out) that one of the first 

 things to do, where it is at all possible, is to get rid of the cedar 

 trees. 



On apple leaves the rust appears as small roughened spots, 

 generally in the form of a distinct ring. The tissue of this ring 

 is thickened and on the under surface of the leaf there are 

 numerous little protuberances, while on the upper surface the 

 tissue turns yellow and finally a bright orange. On the fruit 

 the disease is less conspicuous, but appears about the same as on 

 the under surface of the leaves. 



Varieties of fruits differ greatly in their susceptibility. 

 Among apples the Wealthy is conspicuous for its liability to the 

 disease, and the bright orange spots will be found on the leaves 

 of this variety if there is any of the disease in the neighborhood. 



When the disease cannot be controlled by destroying the 

 cedar trees, the only thing to do is to resort to spraying and the 

 same applications given for the scab are usually sufficient to 

 keep this disease in check, though they will not entirely 

 eradicate it. 



Blotch. This is a relatively new disease and is much more 

 common in the Middle West than elsewhere, but is sometimes 

 found in most apple sections. It resembles the scab very closely 

 and is often mistaken for it, but on the fruit it is apt to be 

 scattered rather uniformly over the entire surface, while the 

 scab is confined to one side of the fruit. The blotch also makes 

 a less compact growth on the areas affected. It produces cankers 



