188 NEBRASKA STATE HORTICULTURAL SOCIETY 



know when the fungi begin to grow is that while he can kill them 

 with Bordeaux mixture as long as they have not penetrated 

 the tissues, when that is accomplished and they are safely in- 

 side of the leaf or fruit it is quite useless to spray. Here then 

 is one of the most important things which a fruit grower must 

 know as much about as possible, and it will pay him to give 

 much time and thought to it. 



SOME FACTS ABOUT PLANT DISEASES. 



Another thing to be remembered is that some plant diseases 

 can be "cured," and many can not. Thirst can be cured if the 

 trouble is in the soil, and the roots are all right. So starvation 

 can be cured by enriching the soil, if the roots, stem and leaves 

 are in good condition. Mild cases of poisoning can be cured, 

 but severe cases invariably prove fatal. Wounds that have been 

 neglected are incurable, but if taken when first formed, and 

 treated properly they may generally be made to heal quickly 

 and effectively. The loss of necessary organs is not necessarily 

 irreparable. Leaves will sometimes appear after they have 

 been destroyed by insects or fungi. Roots will often push out 

 to take the place of those which were cut off, and even flowers 

 which have been destroyed will be replaced by a later set if the 

 tree is in vigorous condition. On the other hand diseases due 

 to fungi are generally incurable in any proper sense. An in- 

 ternal leaf fungus can not be eradicated when once it is inside 

 of the leaf, and so a fruit rot or a stem rot can not be remedied. 

 In such cases prevention is all that can be done. We can pre- 

 vent the fungus from getting into the leaf, stem or fruit, but 

 when once it is inside it is safe from any sprays or other 

 remedial measures which we can employ against it. 



AVOID QUACKS. 



The last thing which I think the fruit grower should know in 

 connection with this matter of plant diseases is that here as 

 elsewhere there are quacks to be avoided. There are all sorts 

 of patent medicines advertised for curing all sorts of plant di- 

 seases. Now these things are just like the patent medicines 

 which fill so many yards of shelving in the drug stores in every 



