82 STATE POMOLOGICAL SOCIETY. 



are many apple trees which are unhealthy. It is not always 

 so easy to determine the exact cause of the unhealthy condi- 

 tion. We have tried to become familiar with the diseases by 

 visiting orchards, by having material sent to us for examination, 

 and by careful laboratory study and inoculation experiments. 



There are a number of things which may give an apple tree 

 an unhealthy appearance or may even cause its death. Among 

 these are : winter killing, poor drainage, lack of nutrition, fail- 

 ure to cultivate, and attacks by fungi and insects. 



It is readily seen that the most of these causes of diseases 

 are directly under the control of the apple grower. This con- 

 trol should begin early, in the selection of a good location for 

 the orchard, and in properly preparing the land before the trees 

 are set. This should be followed by giving the young trees 

 the same amount of care that would be given to other growing 

 plants. It is rather unusual in our experience to find a man 

 who is giving as much attention to his young orchard as he 

 would give to a crop like corn or potatoes from which he ex- 

 pected to receive returns the same year. 



By practicing what might be called good orchard manage- 

 ment, many of the causes of unhealthy trees would be entirely 

 removed and others would be partially controlled. 



The control of diseases caused by fungi requires in some 

 cases special knowledge of the fungus concerned but in most 

 cases the apple grower could protect his trees and fruit by 

 simply following the methods of treatment which have been 

 recommended by Experiment Stations, Agricultural Colleges, 

 and successful orchardists even though he knew little about the 

 causes of the disease. It is natural, however, for us to take 

 greater interest in things of which we have some knowledge 

 and it is easier to fight an enemy if we know its methods of 

 attack. For this reason it seems well in this paper to discuss 

 the characters of fungi before taking up diseases caused by 

 fungi. 



Fungi are low forms of plant life, they do not. have the green 

 coloring matter with which we are so familiar in the higher 

 plants, and for that reason they are unable to manufacture or- 

 ganic food. There are many thousands of species of fungi 

 which differ widely in form and manner of life. All fungi, 

 however, agree in certain characters. They are all composed of 



