* 



240 



EXPERIMENTS IN PREVENTING LEAF DISEASES OF NURSERY 

 STOCK IN WESTERN NEW YORK. 



By D. G. FAIRCHILD. 



[Plates XXI-XXIX.] 



It is the intention to give in the following paper a brief account of 

 experiments made during the seasons of 1891 and 18913 with a view of 

 preventing the various leaf diseases of nursery stock. These experi- 

 ments were carried on at Geneva, N. Y., one of the largest nursery 

 centers east of the Mississippi. The kindness of Dr. Collier, di- 

 rector of the New York State Agricultural Experiment Station, made 

 it possible for the w r ork to be done upon the station grounds, where 

 proximity to the laboratories and assistance from the station staff 

 greatly facilitated the work. 



To bring together in one article the results of the experiments, it will 

 be necessary to repeat in part matter that has previously been pub- 

 lished.* 



The original object of the experiments conducted at Geneva was to 

 throw light upon the following questions: 



(1) Can the leaf-blight of pear, cherry, plum, and quince stocks and 

 the powdery mildew of the apple be prevented by the use of Bordeaux 

 mixture or ammoniacal solution of copper carbonate? 



(2) What effect is produced upon the growth of nursery stock, budded 

 and not budded, by repeated treatments with Bordeaux mixture and 

 ammoniacal solution? 



(3) What effect, if any, has the variety of stock upon the scion or 

 "bud" with respect to its resistance to leaf-blight? 



While the experiments have thrown considerable light upon the 

 first and second questions, the nursery was not extensive enough nor 

 the soil uniform t enough to admit of any but general conclusions being 

 drawn as to the third question. Further, the experiment was begun 

 so late in the season that it was not possible to secure stocks of uniform 

 size, and it is doubtful if any experiments, unless made upon uniform 

 soil, with stocks grown from cuttings, will settle in a satisfactory 

 manner a phase of this problem in which there are so many variable 

 factors. 



The various leaf diseases will now be discussed, together with the 

 results of the experiments made for preventing them. The numerous 



"Annual Report of -ttie &eretaVy.o Ap'/cujture for 1891, p. 368. Bull. No. 3, Div. of 

 Veg. Pathology, pp. 57-60. Ten'th' Itnn .'.Report N. Y. Agrl. Expt. Sta., 1892, pp. 



1 79-18 1. /,::*; %:;Y* : * ' 



t As the expefinJcfnts f/fagreSsefl 



-.pJafrily evident that a strip 30 feet or so 

 wide, at the west end of the block, had at some previous time received fertilizers, 

 which rendered it eminently suited to the needs of pear stocks. As no accnrato 

 record of this portion of the farm seems to have been kept, it was impossible to, 

 ascertain what fertilizers had been used upon the strip. 



