240 
EXPERIMENTS IN PREVENTING LEAF DISEASES OF NURSERY 
STOCK IN WESTERN NEW YORK. 
By D. G. Fairchild. 
[Plates XXI-XXIX.] 
It is tlie intention to give in the following paper a brief account of 
experiments made during the seasons of 1891 and 1892 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 work to be done upon the station grounds, where 
proximity to the laboratories and assistance from the station stall 
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) Gan the leaf-bliglit 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 efiect is produced upon the growth of nursery stock, budded 
and not budded, by repeated treatments with Bordeaux mixture and 
ammoniacal solution? 
(3) What ehect, if any, has the variety of stock upon the scion or 
“bud” with respect to its resistance to leaf-bliglit? 
While the experiments have thrown considerable light upon the 
first and second questions, the nursery was not extensive enough nor 
the soil uniformf 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 
lac tors. 
The various leaf diseases will now be discussed, together with the 
results of the experiments made for preventing them. The numerous 
* Annual Report of the Secretary of Agriculture for 1891, p. 368. Bull. No. 3; Div. of 
Veg. Pathology, pp. 57-60. Tenth Ann. Report N. Y. Agrl. Expt. Sta., 1892, pp. 
179-181. 
t As the experiments progressed it was plainly 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 accurate 
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. 
