EXPERIMENT STATION EEPOET. 361 



The scarcity of systematic investigations concerning the 

 mineral constituents of fruit-bearing plants and of fruits, 

 rendered it necessary to ascertain their ash constituents 

 under definite soil conditions, and to study the effect of 

 special articles of plant-food on the mineral constituents of 

 the growth produced by their aid. It was assumed that in 

 case some definite change in the relative proportions of the 

 mineral constituents was noticed, a safer basis could be ob- 

 tained for distinguishing between the influence of season, 

 location, the general character of the soil, etc., and the 

 influence of the amount and the kind of the available plant- 

 food applied. A portion of land in charge of the horticul- 

 tural department of the Massachusetts Agricultural College 

 has been set apart for that purpose since 1874. 



Wild and cultivated varieties of grape-vines were the first 

 plants chosen for the investigation. 



The experiments have been extended in the course of time 

 to strawberries, currants, blackberries, raspberries, apples, 

 pears, cherries and peaches. 



The results obtained with grape-vines and strawberries, 

 which have been published in previous reports of the College 

 (1875-76), in the reports of the State Board of Agricul- 

 ture (1879-80), and in the Massachusetts Ploughman 

 (1877-78), and elsewhere, have established the fact that 

 fruit-bearing plants respond decidedly, as far as their compo- 

 sition is concerned, to the application of special manures. 



The currants, raspberries and blackberries raised during 

 the past year are at present under examination, and the 

 fruits of most of the trees will be ready for examination a 

 year or two hence. 



The appended report of Prof. Maynard refers to the pre- 

 sent condition of these experimental fruit plats, five in 

 number. His statement regardinrj the serious influence of 

 manuring peach trees in particular, without reference to 

 wants, deserves attention. 



VII. Peaches and Peach Yellows. 



The interest manifested by frequent inquiries regarding 

 the management of diseased peach trees on the College 

 grounds, has to serve as an excuse for introducing the sub- 



