302 STATE HORTICULTURAL SOCIETY. 



rains also wash ofiF the materials which are applied to the trees. Professor 

 Atkinson has examined diseased fruit taken from the orchard in which 

 the experiments were made and has found that a large part, if not all, of 

 the injury done to the apples by fungi was primarily caused by the apple- 

 scab fungus. The leaves were also more or less injured but this was due 

 partly to the action of other fungi as well as the fusicladium. However, 

 the latter may be considered as the worst pest and any treatment which 

 will effectually check it will undoubtedly render the others harmless 

 also. 



The life history of the fungus has not been well determined. Mr. Faib- 

 OHILD, of the division of pathology at Washington, writes me that the 

 infections take place earlier in the season than was supposed; in fact that 

 it is probable that the disease often obtains a foothold even before the 

 petals fall from the trees. The experiments made here the past season 

 tend to confirm the statement. The application of some fungicide before 

 the buds of the apple open will probably be as valuable as any later treat- 

 ments which may be given. When the fungus has once penetrated the 

 plant tissues, there can be no efficient remedies for it. The fungicide 

 should be upon the tree before the spores of the fungus germinate; and 

 those of the apple-scab occasionally seem to be growing even before the 

 opening of the first leaf buds. The apple-scab first appears upon the fruit 

 in the form of grayish, slightly sunken spots. These generally are circu- 

 lar at first but when several grow together their outline is irregular. As 

 the spot enlarges the center becomes quite dark, even black. At the edges 

 may be seen the epidermis or skin of the apple; it is loo.sened by the dis- 

 ease, and forms a light colored line which plainly divides the diseased from 

 the healthy tissues. 



The codlin-moth lays its eggs early in the spring in the blossom end of 

 the apple, before the fruit has turned down. The larvae, or worms, which 

 develop from these eggs, make the apples wormy. The time for fighting 

 this pest is fortunately the same as that for the apple-scab, and in this fact 

 lies the value of a combination of insecticides and fungicides. As soon as 

 the apples hang down, the arsenite may be omitted, but the use of 

 the fungicide may still be advisable. 



The pruning and the spraying of fruit trees are two subjects which are 

 closely related. This is especially true in the case of the apple. Moisture 

 is favorable to the development of the apple-scab fungus. When the tops 

 of the trees consist of a tangled mass of large and small branches, they are 

 much longer in drying out than when they are open. Not only is a shelter 

 given to fungi, but their growth is encouraged, and each tree becomes the 

 distributing center of some disease. The mischief is also aggravated by 

 the fact that it is as difficult for any remedies to gain an entrance as it is 

 for the light and air. It is impossible to spray such trees to advantage, 

 even granting that the fruit borne by them would warrant the expense. 

 The head of the tree should be open so that all parts may be reached 

 easily with the spray. 



The actual expense of spraying is also largely increased when the tops 

 of the trees are not well pruned. A well-sprayed apple tree has its leaves 

 and fruit covered with a thin layer of the material applied, so that the 

 poison will be present wherever a spore may fall or an insect feed. If the 

 work is not done in this manner, the tree remains more or less unprotected. 

 It naturally follows that a tree bearing many unnecessary branches will 

 require more material to protect it. But much material is also wasted in 



