4 BULLETIN 1252, U. S. DEPARTMENT OF AGRICULTURE. 
of apothecia, while those that had been plowed and cultivated before 
this time were practically free from them except in tree rows or other 
unplowed areas. Apothecial clusters were sometimes found at the 
rate of three or more to the square foot in the uncultivated tree-row 
spaces and yet were entirely absent in the cultivated portions of the 
orchard. 
Fruit that is plowed under and deeply buried is not likely to 
produce apothecia, and plowing or deep harrowing in the early 
spring and during blossoming is likely to disturb the partly formed 
apothecia and prevent further development. 
Different soils are not equally favorable to the development of 
apothecia. They were found in greater abundance on the moist 
bottom lands than on the well-drained hills. They seemed to be 
almost entirely absent on the coarse “ red-shot ” clay soils. 
Orchards that were free from apothecia through cultivation or 
otherwise were found to be practically free from biossom infection 
and usually relatively free from brown-rot. 
FRUIT INFECTION. 
After the blossom stage was passed practically no brown-rot was 
found on the prunes and cherries till they approached maturity. 
The green fruit is usually relatively resistant to disease, and the low 
midsummer rainfall was unfavorable for infection. As the harvest 
season approached, brown-rot again became evident, but during the 
five years when the disease was under special observation there was 
never a severe epidemic of brown-rot in the orchard, the larger part 
of the losses sustained occurring on the harvested fruit while in 
transit or while at the drier or the cannery. In some years, how- 
ever, the spread of the disease in the orchard has caused severe losses. 
It was estimated by the growers that the epidemic in the fall of 1923 
resulted in the rotting of about one-third of the prune crop while 
still on the trees. (Pls. IV and V.) 
SPRAYING EXPERIMENTS ON PRUNES. 
Spraying experiments were made in the Italian Prune orchards of 
A. W. Moody, of Felida, Wash., during the four years, 1915-1918, 
and in the Italian and Agen (Petite) Prune orchard of L. T. Rey- 
nolds, at Salem, Oreg., in 1916 and 1919. The work was done with 
gasoline power sprayers, and special attention was given to securing 
a fine, well-distributed spray. 
SPRAYING EXPERIMENTS IN 1915. 
The experiments in 1915 were started with the standard spraying 
materials, 44-50 Bordeaux mixture, 8-8—50 self-boiled lime-sulphur, 
and commercial lime-sulphur 1 to 50 and 14 to 50. <As the season 
advanced it was found that these materials did not spread and stick 
well on the fruit, and modifications were made to meet these condi- 
tions. Two pounds of rosin-fishoil soap were added to each 50 
gallons of Bordeaux mixture or self-boiled lime-sulphur, and in the 
second orchard 2 gallons of flour paste (containing 2 pounds of 
