208 AGRICULTURE FOR COMMON SCHOOLS 



There is a similar loose smut which attacks wheat and 

 barley, but no effective remedy is known for it. Wheat is 

 often attacked by a smut which makes the inside of the grain 

 a mass of black powder or spores. The kernel when broken 

 open has a bad odor. This is known as stinking smut. It 

 can be controlled by treating the seed wheat with formalin 

 the same as for oat smut. We often see large black masses 

 attached to corn plants. This is corn smut. No sure remedy 

 is known for it. It is best to collect all such masses and burn 

 them on the trash pile. 



2. Rusts. — There are many kinds of rusts and they are to 

 be found on nearly all species of plants. One of the most 

 common is the wheat rust. Wheat rust is of two kinds. The 

 kind that makes the reddish spots on the leaves is called 

 orange-leaf rust The kind that forms blackish blotches on 

 the stem is known as black-stem rust. No remedy is known. 

 The same rusts attack oats and barley, but rarely rye. 



Growers of blackberries, raspberries, and dewberries often 

 have their plants attacked by a rust known as anthracnose. 

 It appears as gray patches with distinct purple borders on the 

 lower part of the stems and soon causes them to wilt and die. 

 The best remedy is to cut out and burn all diseased stems. 

 Spraying with copper sulphate solution before the buds open 

 and with Bordeaux mixture afterward is helpful. 



3. Blights. — A disease which causes the leaves of a plant 

 to wither and die without any very easily discovered cause is 

 usually called a blight Pears and quinces are often attacked 

 by leaf-blight, which causes the leaves to die and fall to the 

 ground. The twigs appear black and dead and the fruit be- 

 comes hard and knotty. This blight can be controlled by 

 spraying with Bordeaux mixture several times during the 



