272 DISEASES OF CULTIVATED PLANTS 



greyish-white tufts of fruit arranged in concentric circles. 

 These patches continue to increase in size, and two or more 

 such patches often encroach on each other, and cover the 

 greater portion, or entire surface of the fruit. Such patches 

 are often present while the fruit is still hanging on the tree, 

 and in many instances such diseased fruit does not fall, but 

 remains hanging until leaves appear the following season. 



On cherries, plums, peaches, etc., the whitish tufts of 

 fungus fruit are usually irregularly scattered, and not arranged 

 in circles. 



In some instances when apples are attacked, no fungus 

 fruit is formed on the surface until the following season, but 

 the skin of the apple becomes tough like parchment, and 

 changes to a black colour throughout. 



Woronin has given an excellent and beautifully illustrated 

 account of the Monilia stage, and indicated that it was the 

 conidial stage of Sckrotinia, but did not discover the asco- 

 phore. 



Infected fruit does not rot and decay, but gradually dries 

 up and presents a shrivelled or mummified appearance, 

 whether lying on the ground or hanging on the tree. The 

 substance of such fruit is crowded with the mycelium of the 

 fungus, in fact the whole fruit may be considered as a kind of 

 sclerotium, and the spring following its production its entire 

 surface becomes covered with a dense crop of Monilia spores. 



Norton has met with the ascigerous form of fruit abundantly 

 on mummified plums and peaches that have been lying 

 buried for two years in the orchards in Maryland. 



Monilia stage, tufts consisting of simple or branched chains 

 of ovoid or lemon-shaped hyaline spores, 21-25X10-12 /u. 

 Ascophore brown 1-2 cm. across, in clusters on buried fruit. 



It is very important that all infected fruit, whether hanging 

 on the trees or lying on the ground, should be collected and 

 burned or deeply buried. All dead or cankered twigs should 

 be similarly treated. 



When the disease is known to exist, the trees should be 

 thoroughly drenched also the surrounding ground during 

 the winter with a solution of sulphate of copper. When the 

 leaves are half grown, spray with a dilute solution of Bordeaux 

 mixture. Norton says that almost all the disease present on 

 peaches followed insect bites or other injury. On plum the 

 disease was very bad, probably following the work of curculio. 

 This suggests that insects favour the entrance of the fungus 



