58 STATE BOARD OF AGRICULTURE. 



may harbor the disease if allowed to remain in the vicinity of the plum 

 orchard. 



Shot-hole fungus of plum and cherry is a disease affecting the leaves, 

 causing small circular pieces to drop out, thus making the blade of the 

 leaf appear as if perforated with shot. Several kinds of fungi cause 

 this appearance and are capable of doing much injury to the plant. 

 Spraying has been found quite effective in checking it. 



Apple scab. — The scabby brown spots on apples commonly known by 

 this name, are familiar to every one. They are caused by a fungous 

 parasite which works just under the skin of the apple and. when very 

 bad, causing distortion and cracking of the affected part. The spots are 

 most abundant at the blossom end of the apple, due to the fact that 

 drops of moisture remain longest here, thus enabling the spores of the 

 parasite to germinate. It also attacks the leaves, causing sooty blotches. 

 The spots on these leaves give rise to a winter or resting spore from 

 which the disease starts anew the next spring. 



It is especially bad in cold, wet seasons, and such seasons are the most 

 unfavorable for controlling it by spraying. The scabby spots also allow 

 the apples to dry out, and worst of all, make a favorable point of entrance 

 for the spores of a number of other fungi, causing the soft rots of the 

 fruit. One of the commonest of these "moulds"is the "blue mould" which 

 causes a soft rot of the apples in storage, the rotting usually starting 

 in one of the scabby spots. Stored fruit is least liable to these "soft 

 rots" when kept comparatively dry and cold. A cellar containing a fur- 

 nace is a poor one for storing fruit of any kind. 



Spraying the trees early in spring and several times during the season 

 is a paying investment for the grower of apples. 



Stinking smut of wheat. — This is a serious disease in some places, being 

 especially destructive in the wheat-growing states of the west. It does 

 not show itself until the heads are nearly ripened when the chaff begins 

 to stick out. This is due to the fact that the kernels are swollen, thus 

 causing the chaff to spread apart. These kernels are dark colored and, 

 when crushed, contain a fine black or dark brown powder with an offen- 

 sive odor. This powder consists of the spores of the fungous parasite 

 and there are enough in a few diseased heads to contaminate a good 

 many bushels of seed wheat. These spores stick to the seed wheat, ger- 

 minate at the same time as the wheat and attack the young seedlings. 



Thus, to prevent the appearance of the disease it is necessary to sow 

 clean seed. If the seed has been contaminated with smut it can be treated 

 with excellent results either by the Jensen hot water treatment or with 

 solutions of copper sulphate or formalin. Any of these treatments have 

 been found very effective in killing the spores in the seed and thus 

 preventing the smutting of the crop. 



