ISO State Hortimiltural Society. 



Virginia and West Virginia I have seen the entire crop of some 

 varieties destroyed. 



Under favorable weather conditions, bitter rot spores, that find 

 their vv^ay to the apple, germinate v^ithin a fev^^ hours and the mi- 

 nute threads of the fungus penetrate the skin and grow^ very rap- 

 idly, branching in every direction. They absorb their nourishment 

 from the cells of the apple, killing the tissue, and thus produce the 

 brown sunken spots known as bitter rot. When the spots are about 

 half an inch in diameter the fungus throws up bundles of threads, 

 which rupture the skin and give forth pink, sticky masses of spores. 



It is chiefly through these summer spores that the disease is 

 disseminated, and countless millions of them are produced from one 

 rotten spot. The rains splash them from fruit to fruit and insects 

 carry them from tree to tree. 



CANKERS. 



The fungus also attacks the limbs and twigs, forming dark 

 sunken spots known as cankers, which not only injure the tree, but 

 'form sources of infection for the fruit. 



SOURCES OF INFECTION. 



The fungus is carried over winter in the rotted fruit of the 

 precious year's crop and in the limb cankers. During 

 June and July these give off spores that start the in- 

 fection on the new crop. When a single apple on a tree 

 becomes infected the disease may then easily spread to the entire 

 crop. Although the first infection may take place as early as the 

 middle of June, a serious outbreak is not likely to occur before July 

 or August. 



WEATHER CONDITIONS. 



The weather is a very important factor in the development of 

 bitter rot outbreaks. A few days of hot, showery weather may 

 start an epidemic that would destroy the entire crop of some varie- 

 ties. 



No matter how many spores may be present, no harm will re- 

 sult without a high temperature, coupled with plenty of moisture. 

 This fungus, being a plant, requires heat and moisture in which 

 to germinate and grow, as does any of your farm crops. 



