in this case should be collected and destroyed. The operation 

 of tipping for American Gooseberry Mildew has this object in 

 view. In some mildews, e.g., Apple Mildew, few or no resting 

 spores are formed and the mycelium hibernates in the buds 

 and develops with them in spring. In this case affected buds 

 should be cut out. 



In most other leaf-fungi winter or resting spores form in 

 the old leaves, hence the invariable advice of the mycologist to 

 burn affected foliage. It is now known, however, that leaf- 

 fungi not infrequently also attack the young wood and pass the 

 winter on twigs on the tree. Apple and Pear Scab are the 

 best known and most striking examples of this form of hiber- 

 nation, and the great/ importance of removing, scab-infected 

 wood is now recognised by all up-to-date growers. 



(b) Fungi attacking the Fruit. The most destructive fungi 

 of this group are those causing the Brown Eots of pear, apple, 

 plum, cherry and other stone fruits. In these diseases the 

 fungus remains in the attacked fruit and, drying them up, 

 forms the well-known mummies which hang on the trees 

 during winter. The mycelium hibernates in the mummies, 

 becomes active the following season and liberates spores. In 

 addition to spore-infection the inoculation of new fruit is also 

 brought about if the latter is in direct contact with a mummy 

 as is often the case when fruit is borne on spurs. An impor- 

 tant point to remember, however, is that Brown Hot fungi 

 also attack flowers and shoots, forming Blossom-Wilt, Wither- 

 tip and Canker, and that when the shoots are infected the 

 fungus hibernates in them also. In each of the Brown Rot 

 diseases, therefore, attention should be concentrated on remov- 

 ing not only mummies, but all wood that has been killed by 

 Brown Eot the previous season. 



Apple and Pear Scab are only second in importance to the 

 Brown Eots. The scab fungus hibernates on the wood and 

 passes from this to the leaves. From the leaves it spreads 

 to the young fruit. A somewhat similar method is found with 

 the less prevalent diseases Bitter Eot and Black Eot of apples. 



(c) Fungi attacking the Wood. This group is connected 

 with the last by the Brown Rot and Scab fungi which at times 

 seriously injure the wood of both plums and apples. The 

 fungi particularly in view under the present heading are, how- 

 ever, those which attack the wood only, and these invariably 

 gain entrance through a wounded surface or an area of dead 

 tissue such as a twig or broken branch. The most important 

 fungi of this group are those causing Canker, Silver Leaf, Die- 

 Back of plum, although there are many others. 



In all these diseases the first point to ascertain is the manner 

 in which the fungus gains entrance to the tree. Any wound 

 may probably serve, but in ordinary orchard conditions 1 there 

 are generally particular injuries which act as weak points in 

 the armour of the tree. As an instance, Apple Canker may 



