CHAPTER XIX. 



FUNGOUS DISEASES OF GARDEN PLANTS. 



HOW TO PREVENT AND CURE THEM. 

 " An ounce of prevention is better than a pound of cure." 



ECENT investigations have acquainted us pretty 

 well with the true nature, modes of propagation, 

 etc., of most of the fungi which attack and 

 damage our garden crops, and cause the various 

 rots, blights, and mildews. To find a sure 

 cure or sure prevention has been the great prob- 

 lem ; unfortunately it must be confessed that in 

 this respect we as yet know far less than is de- 

 sirable, or required to give us complete control 

 over these diseases. The latter destroy the tissues ; and tissues 

 once destroyed, cannot be rebuilt. A cut or burn on a person's 

 flesh will heal up, and skin will grow again and spread over the 

 burnt surface from a near starting point; but a leaf burnt up with 

 scab, or a berry touched by rot, is a leaf or a berry gone beyond 

 the possibility of recovery. The term "cure," therefore, has no 

 application in the treatment of fungous diseases. But we may be 

 able to kill the fungus spores, and thus prevent the spread of 

 the diseases. All our efforts must be exerted in this direction. 

 Here again, as in the case of insects, we must look to change of 

 location — planting at the greatest possible distance from any 

 ground where the same vegetable was grown before, as to the 

 first feasible preventive measure to be adopted. Even this, as in 

 the analogous case of insects, is not an absolute protection, and 

 unfortunately our senses are not acute enough to tell us from 

 what source to expect the infection, and when to expect the 

 attacks. 



Heat and moisture favor the development and spread of 

 most of these troublesome plant maladies. Consequently pru- 

 dence would dictate the use of precautionary measures on hot 

 days after warm rains, or during damp and sultry weather. We 

 should be quick about it, too. While we have means to kill the 

 germs and prevent their starting into life, nothing has as yet been 

 found that will affect the growth of the thread-like mycelium 

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