SOME OBSERVATIONS ON PEACH-YELLOWS. 



That healthy and vigorous peach trees can be grown to the age of 

 six to ten years in New England needs no demonstration, but we 

 seldom find healthy treqs of a greater age on account of the destruc- 

 tion resulting from the cold and by the disease called the " yellows." 



In this bulletin we shall discuss the causes of this short life and 

 the "yellows," that disease which has been so destructive to the 

 peach tree in all sections of the country. 



THK " YELLOWS." 



The symptoms of this disease are as follows : — 



1. A sickly yellowish green color of the foliage. 



2. Small leaves, often clustered and tinged with red. with a small 

 amount of chlorophyll in the cells. 



o. The new shoots are small and wiry and grow in clusters or 

 tufts, especially if they come out on the trunks or main branches, 



4. The fruit ripens prematurely, is small and of a high color and 

 insipid or bitter to the taste. 



Trees may present the yellow sickly appearance from want of food 

 or from injury, but if the fine wiry siioots, the prematurely ripened, 

 high colored and bitter fruit are present, the trees have the " yel- 

 lows." 



It is stii! an open question whether there is a specific germ or 

 microbe which develops at the expense of the tissues of the tree un- 

 der favorable conditions, as in the diseases of a similar nature attack- 

 ing other plants and animals but, from the development of the dis- 

 ease, it is reasonable to suggest that it may be of a similar nature to 

 tlie pear blight, and other kindred diseases. 



Tiie same disease, apparently, although we have n)ade no careful 

 study of the tissues, often destroys the wild cherry, the wild plum, 

 the sweet birch, (Betula lenta) and other trees. 



In 1869 a small orchard of 100 peach trees wa^ ])'auted on a light 

 giavelly piece of laud on the College grounds. Ti)ese, after gome 

 years of indifferent culture, reached the bearing s.tage. In 1873 many 

 of ihem showed signs of the disease, but after a severe heading back 

 and special manuring they were brought into a healthful condition 

 and bore fruit. These were the trees which Professor Goessmann, a 

 few years later, treated with special manures and upon which Profes- 

 sor Peuhallow made at the same time extensive microscopic examina- 

 tions, publishing the results. 



The writer having the above trees under his care then and up to 



