154 MANUAL OF FRUIT DISEASES 
as the fruit is setting, and (2) later, depending on the amount 
of rain. In seasons of brief shower-periods followed by drying 
weather, spraying is regarded as unnecessary. (Brown-rot is 
more fully discussed under Peach, page 270.) 
Frost-InsJurY 
Caused by the action of low temperatures 
Like other fruit-trees, the apricot suffers from the effects of 
frost. Injury by low temperatures in winter, winter-injury, is 
perhaps the most destructive of all apricot troubles. Collar- 
rot, or crown-rot, is particularly common and injurious. (For 
fuller discussion and additional references see under Apple, 
page 35.) 
REFERENCE 
Stewart, F. C., Rolfs, F. M., and Hall, F. H. A fruit-disease survey 
of western New York in 1900. Apricot diseases. Collar rot. 
New York (Geneva) Agr. Exp. Sta. Bul. 191: 303-304. 1900. 
* ScaB 
Caused by Cladosporium carpophilum Thiim. 
The scab disease, or freckle as it is often called, occurs on 
stone-fruits other, than the apricot. In fact it affects the peach 
very commonly. Black scab spots are produced on the fruits 
and pale-gray blotches with dark margins are developed on the 
twigs. The first record of the disease on apricot in California 
dates back to 1909. While it has attracted some attention in 
that state, yet it is said to have never been sufficiently trouble- 
some to warrant treatment. It has been found abundantly - 
in Connecticut and Texas. (Fuller discussion under Peach, 
page 294.) 
