FUNGI II 



Moulds and mildews are commonly differentiated 

 from other fungi by being confined more to the 

 surface of the host plant, their mycelium penetrating 

 only a short distance into the substance of the leaves, 

 shoots, etc. 



For the destruction of fungus spores, the fungicide 

 must be applied either in summer or in winter, 

 according as it is the summer spores or winter spores 

 which have to be attacked. One essential to the 

 successful dealing with the summer spores is to do the 

 spraying on the very first appearance of the disease : 

 in most cases, however, such spraying results only 

 in a checking of the attack, for the mycelium is not 

 destroyed by it, and a renewed formation of spores 

 occurs later on, necessitating a repetition of the 

 spraying operation. 



Besides spraying the trees in winter for the destruc- 

 tion of the winter spores, it is very important that 

 all dead leaves, shrivelled fruit, and prunings should 

 be collected and burnt, for it is on them that the 

 spores are generally found. All wounds should be 

 attended to and tarred, for in many cases it is through 

 some wound that the fungus spores gain an entry 

 into the tree; unfortunately they may enter through 

 wounds too minute to be noticed, such as those made 

 by the woolly aphis, and the destruction of pests of 

 that description is, therefore, one of the best ways of 

 keeping the trees free from the attacks of fungi. 



There are practically only two substances effectual 

 in destroying fungus spores — potassium sulphide, and 

 copper, the latter being generally used in the form of 

 one of its sulphates. 



