8 



N. H. AGR. EXPERIMENT STATION. 



[Bulletin 157 



4). The cuticle is finally ruptured and the usual form of spore 

 and sporophore exposed (Fig. 5) . 



Late in the fall perithecia begin their development on the 

 fallen leaves (Fig 6). They reach maturity by the following 

 spring, and their spores are scattered in April and May. They 

 are blown to the young foliage and start the disease anew. 

 The production of this perithecial stage is especially common 

 when the leaves fall upon the sod and are protected by their own 

 number or bv being partially covered with grass. 



Treatme7it. The disease can be controlled by spraying. To 

 be most effective the sprayings must be made before the fungus 

 has gained entrance to the host as when it is once beneath the 

 cuticle it may continue to develop in spite of the application of 



Fig. 4. — Early stage 



Scab Spot on Storage Apples 



Fig. 5. — Later stage. 



fungicides. In badly affected orchards it is advisable to make 

 a spraying before the leaves are out. At this time copper sul- 

 phate, 1 pound to 25 gallons, may be used, or a strong Bordeaux 

 or lime-sulfur solution. A second spraying should be made 

 after the leaves have expanded and before the flower buds open. 

 Bordeaux or lime-sulfur may be used for this and for later appli- 

 cations. A third spraying should be given when most of 

 the petals have fallen. This application is the most important 

 of the season. When the disease is at all serious two more spray- 

 ings are needed, the fourth about three weeks after the third and 

 the fifth early in August to prevent a late spread of the disease. 

 For a discussion of fungicides see pages 29-32. The fact 

 that the fungus winters in the leaves makes it evident that much 

 may be accomplished by their destruction. A practical demon- 



