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' ExprerIMENts with Nursery Srook. 659 
that treated once by mistake. This constant difference in diam- 
eter, at three inches above the base (“caliper”), is of such import-: 
ance as to merit further observations, The author regrets that 
the control rows were left so small, and feels warranted in drawing 
rut only the general conclusion, which was strikingly demonstrated, 
that the fungicides were effective to a remarkable degree in pre- 
_yenting the disease and that treated made the best growth. 
~Pirum Lear—Buiear (Cylindrosporium padi Karsten). 
- The plum leaf-blight in western New York, aside from giving 
~ much trouble to nurserymen, does very great damage to many 
varieties of bearing trees, defoliating them in August and Sep- 
tember. This disease is considered by the plum-growers in the 
vicinity of Geneva, as their most persistent enemy. A _ large 
orchard belonging to E. Smith & Sons, two miles northwest of — 
the city, was, they informed me, winter-killed about thirty years 
-- ago because of defoliation the summer previous. It is a common 
opinion among orchardists that leaf-blight, through its retarding 
effect upon the maturation of the wood, renders the trees incapa- 
ble of withstanding the changes in temperature of a trying winter. 
Whatever the explanation of this fact may be, it seems self- 
evident that a tree which drops its leaves before the normal 
season suffers very material loss. 
Of nursery stocks, the native-grown seedlings suffer the most 
from this disease, often losing all their leaves by the middle of 
| August. Myrobolan and Marianna stocks are not to any extent 
subject the firsh season. In entire contradistinction to the 
immunity exhibited by pear “buds” which resist to a remarkable 
As degree pear leaf-blight, the budded plum stocks are particularly 



susceptible to plum leaf-blight. Apparently the same conditions 
of rapid growth which afford immunity in the one case tend to sus- _ 
Bal, ceptibility in the other. The two instances offer a fertile field 
a. The experiments on this disease were made with Bordeaux 
mixture and ammoniacal solution upon two. rows of stocks, one of 
erry 
