SECTION IX 

 Fungicides and Insecticides 



Owing to the attention that has been given to the various fungoid 

 diseases of fruits, flowers, and vegetables of late years, a large industry 

 has developed amongst chemists to supply remedies for checking or killing 

 the various diseases. What has already been said about the efficacy or 

 otherwise of insecticides at p. 167 applies with almost equal force to 

 fungicides. The use of these has increased enormously of late years, but 

 the various fungoid diseases seem to enjoy themselves as much as formerly 

 on our crops. Indeed the writer has seen some of the worst cases of 

 fungoid diseases in market gardens upon which large sums of money have 

 been spent annually in insecticides, while other gardens, upon which not a 

 farthing has been spent on either insecticides or fungicides, are practically 

 immune from fungoid diseases and insect pests. Apple trees and pear 

 trees that have been carefully sprayed for Fusicladium have had their 

 fruits attacked quite early in the season; while in other cases, where the 

 usual methods of cultivation were practised, but where no fungicides were 

 used, the fruits were perfectly free from fungoid attack. 



The only fungoid diseases that seem to defy all fungicides and all efforts 

 to check or eradicate them appear to be the " Silver-leaf " of Plums and 

 the " Die-back " of Gooseberries. Some day, perhaps, when more is known 

 about these two terrible diseases, it may be possible to find a means of 

 destroying them. In the meantime Victoria and Gisborne Plums are 

 rapidly falling a prey to the " Silver-leaf " fungus (Stereum purpureum), 

 while Gooseberries are being mowed down wholesale in places by the 

 " Die-back " (Botrytis cinerea). 



Just as many insect pests are undoubtedly due to inferior methods of 

 cultivation, it is possible that the prevalence of many fungoid diseases is 

 due to the same cause. The cultivator, therefore, who pays more attention 

 to the arts of cultivation and manuring his soil, and not so much perhaps 

 to the sciences of chemistry and entomology, will probably find his crops 

 more free from disease of every kind. At the same time, as it is beyond 

 the bounds of human possibility to keep fungoid diseases like that of the 

 Potato absolutely in check, he should be prepared to suppress any sudden 



