EW RK AGRICULTURAL EXPERIMENT STaTIon. 421 
N aes A E S 
that the trees be sprayed just before blossoming and again imme- 
diately after the blossoms fall, but no line of treatment is recom- 
mended. 
Powell recommends picking the fruit before it is fully ripe; 
that is, before it softens. 
LEAF-SPOT. 
(Cylindrosporium padi Karst.) 
Description.— The leaf-spot of cherry, plum and apricot, which 
is caused by the fungus named above, at first appears as minute 
spots on the leaf, a sixteenth of an inch or less in diameter. On 
cherry and plum especially, the spots may have a reddish-tinged 
margin. Afterwards they increase in size and may enlarge to an 
eighth of an inch or more across. ‘The spots soon become dark 
brown with a pale center, and in many cases the diseased tissue 
loosens and drops out leaving a clean-cut hole in the leaf. For 
this reason the disease is sometimes called the “ shot-hole dis- 
ease.’’!" 
The disease may cause serious injury for sometimes the 
trees are nearly defoliated by it. Should this occur when the 
trees are heavily loaded with fruit, as it is especially apt to do 
with plums, the trees may be much weakened in vitality’® and con- 
sequently more liable to winter injury. 
Treatment.— It has been shown conclusively that the leaf blight 
may be controlled by proper treatment with Bordeaux mixture 
but in cherry orchards the treatments cannot be made at the mest 
favorable time for controlling the disease because the spray mix- 
9 
tures adhere to the fruit and injure its market value.’*? From our 
present knowledge of the subject no line of treatment can be 
positively recommended for bearing cherry trees, but it is sug- 
16 Powell, G. Harold. Del. Agr. Exp. Sta. Rept. 1897: 193. 
17 Duggar has shown that a shot-hole appearance in plum and peach foliage 
is not always due to fungous attacks, but may be caused by other injuries, 
notably by spraying with improperly prepared mixtures. See Proc. Soc. for 
Promotion Agr. Science, 1898, and Cornell Agr. Exp. Sta. Bul. 164: 385. 
18 Beach. Annual Rept. this Station, 1896: 385; also Bulletin 98. 
19 Beach. Annual Rept. this Station, 1896: 406. 
