MONTANA EXPERIMENT STATION. 259 



42, The Gooseberry Fruit-worm. 



A near relative of the codling moth which feeds in the goose- 

 berry fruit, causing it to prematurely turn color and later to drop 

 off. Several berries are often bound together. Common in the 

 fruit-growing sections of the state. 



Remedy. — Carefully go over the bushes and pick off the affected 

 berries and destroy them before the worms leave. Do this at least 

 twice in the season. 



FUNGUS DISEASES. 



I, Black Spot, or Apple Canker. 



This is peculiarly a northwest disease and attacks only the ap- 

 ple. It is said to occur in western Montana. The disease is confined 

 to the bark and pioduces characteristic brownish or nearly black 

 spots. The spores are distributed during the early fall. 



Remedy. — Under some circumstances relief may be secured by 

 cutting out the affected parts. Since the disease spreads from No- 

 vember 1st to February ist, it is evident that trees should be coated 

 with a fungicide during this period. On account of frequent storm 5 

 however, it would be difficult to keep a fungicide on the trees. 



2, Crown Gall. 



Various plants, including apple, almond, apricot, blackberry, 

 cherry, chesnut, English walnut, grape, peach, pear, plum, raspberry, 

 and poplar are affected with abnormal growths on the roots which 

 have been called crown-gall. These galls vary from a size as big 

 as a fist or larger down to very small excrescences on the fine roots. 

 Whether or not all of these trees are affected with the same organ- 

 ism is not clear. A serious trouble on apple in Montana. Irrigation 

 seems to favor its development. 



Remedy. — Do not plant affected trees. Examine the roots of 

 all new stock and discard any that shows even the slightest sign 

 of this disease. 



3, Apple Scab. 



Attacks leaves and fruit and sometimes also the twigs. Circu- 

 lar smoky spots oa the fruit which interfere with its development. 

 Spots begin to appear when the fruit is about half grown. They 



