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trees. This is not a fanciful picture because it has happened time and 

 time again in tlie history of horticulture. We might cite chestnut 

 blight, citrus canker and white pine blister rust as examples. There- 

 fore, it behooves the nut culturist to take thought of the nut diseases. 



In the short time which lias been allotted me I cannot take up the 

 diseases of all our northern nut crops. For this reason I am going to 

 dwell only on the diseases of the native nuts, omitting the Englisli 

 walnut with its bacterial blight and the pecan scab which is mainly 

 southern in its range. 



Few of the diseases of nut crops have been carefully studied and 

 even where we know something about them on the wild trees we are 

 not certain as to how they will act when introduced into the "culti- 

 vated" orchard. What I have to say, therefore, in regard to the 

 probable effect of these diseases is more in the nature of a forecast, 

 which, like some of our weather forecasts may prove to be wide of 

 the mark. 



Chestnut Diseases 



Chestnut blight or canker: In 1912 I was fortunate enough to 

 be employed by the state of Pennsylvania during the campaign to 

 head off the chestnut blight in that state. I had an opportunity, 

 therefore, to become intimately acquainted with this devastating dis- 

 ease. As most of you know it is now so wide spread that there is no 

 longer any hope of saving the wild American chestnut from practical 

 extinction. However, the commercial growing of chestnuts need not 

 be seriously affected by this disease except in those sections where the 

 orchards are in close association with the natural growth. 



I will describe this disease briefly for the benefit of those who 

 are not familiar with it. Although called "blight" it is really not a 

 blight as this term is generally used. It is a canker disease which 

 on account of its rapid development soon girdles the branches or young 

 tree and thus causes the wilting and blighted appearance associated 

 with the disease. The cankers are usually oval, slightly sunken, and 

 on young limbs are conspicuous due to the fact that the bark of the 

 canker is reddish brown in contrast to the normal dark green of the 

 healthy limb. When the bark of a canker is peeled off there may 

 be found tawny, fan-shaped growths of the fungous mycelium next 

 the wood. The most conspicuous and characteristic symptom however, 



