PREFACE 



Diseases of plants are numerous and undoubtedly do much 

 injury. This, however, is not so much due to a lack of known, 

 reliable, preventive or curative methods, as to a lack of applica- 

 tion on the part of those who should be most interested in the 

 matter. If the various well proved remedial measures now 

 known, which are neither exorbitantly expensive nor diffi- 

 cult of application, were honestly carried out, the loss from 

 fungus and animal pests would be very materially reduced. 



The most important of remediable and preventive measures 

 combined is cleanliness. Unless this fact is constantly kept 

 in view, and practised, no amount of spraying or other modern 

 method of dealing with disease will produce the desired 

 result. Just now spraying is the order of the day, and under 

 certain conditions is productive of much good ; at the same 

 time spraying alone may be overdone, whereas when used in 

 combination with other measures the success is greater and 

 the cost less. Hundreds of people know, to their cost, that 

 repeated sprayings do not always prevent Apple scab. Why ? 

 Because they do not remove the dead twigs on which the 

 fungus winters. It is sometimes argued that this is impractic- 

 able, which is simply nonsense. The same is true of most of 

 our diseases ; the cultivator is led to believe by the manufac- 

 turer of spraying apparatus of various preparations warranted 

 to cure everything, and frequently supported by expert 

 opinion, that his salvation depends on spraying alone. Not- 

 withstanding such persuasion and advice, the cultivator will 

 find it to his advantage to remove the primary cause of disease 

 whenever practicable, rather than allow it to remain, and 



