PLANT DISEASES AND PESTS 375 



ten days. Such spots soon assume a characteristic yellow 

 color and become slightly swollen on both the upper and 

 lower surfaces. These leaf spots mature rapidly, and 

 within about two months they send out clusters of cylin- 

 drical fruiting bodies on the under surface of the leaf. 

 The fungous spores which are borne in these fruiting bodies 

 are not able to grow on apple foliage, but they are carried 

 to the cedar trees and again produce the cedar apples. 



The damage done by apple rust is very extensive. In 

 some cases entire crops of York Imperial apples are lost. 

 Some varieties are injured more than others. The 

 remedy is to remove all red cedars frcm which the wind 

 can blow the spores to the orchard, and to 

 spray the apple trees with lime-sulphur solu- 

 tion, 1-40, about five to seven times in five 

 weeks, beginning when the blossom buds 

 show bright colors. Bordeaux mixture is 

 almost as good as lime sulphur. 



259. Brown Rot. Brown rot is a fun- 

 gous disease which attacks stone fruits, being 

 most destructive on plums and peaches. It 



also attacks apples and pears. The chief 



rr BROWN ROT 



symptom of this disease is the appearance Th e mummi es 

 of a brown-colored rot . in the fruit. It that carry the 

 may appear while the fruit is still green ^f^* 11 

 or on ripened fruit. Sometimes it makes 

 its appearance after the picked fruit has been sent to 

 market. It causes ripened fruit to decay very rapidly. 

 As the disease progresses on green fruit, tiny, gray, spore 

 masses break through the skin and the wind scatters 

 spores by the thousand to other fruit. The rotted green 

 fruit soon shrivels and dies, and may fall to the ground 

 or hang on the trees. The dried fruit on the trees, known 



