PEACH DISEASES 275 



humidity. The conidia from these sources start the disease 

 in other parts of the peach. From one or more of the several 

 possible sources conidia are carried to the half-grown fruits. 

 These spores germinate, and the tubes enter through an in- 

 jury; the curculio and the peach-scab fungus are the chief 

 agents in making such wounds. The mycelium develops pro- 

 fusely within the tissues of the fruit, the result snowing 

 externally as a brown-rot. Conidial tufts soon appear and 

 conidia are liberated to continue the destructive action of the 

 fungus. Where two or more peaches touch each other, the 

 mycelium grows from the infected peach through the point 

 of contact to the other. In this way the fruits are made to 

 cling to each other, several in a group. 



The fungus is highly favored by a series of cloudy days 

 accompanied by frequent showers, especially at picking time; 

 consequently a great amount of fruit may be destroyed under 

 such weather conditions. Prolonged drizzly weather is far 

 more dangerous than a heavy rain followed by clearing. Hot 

 weather favors the rapid growth of the fungus and increases 

 the danger of its destroying the crop. On the other hand, in 

 a dry, cool season the crop may be expected to remain relatively 

 free from brown-rot. 



Control. 



In applying control measures it should be borne in mind 

 that: (1) all parts of the peach above ground are liable to 

 attack ; (2) the disease is most serious in warmer regions and 

 in warm, wet seasons; (3) total destruction of the crop may 

 come suddenly and unexpectedly ; (4) the fruits and blossoms 

 are affected seriously, which fact is of vital importance when 

 measured in dollars ; (5) the fungus overwinters in the mum- 

 mies and in the cankers, and the mummies are found both 

 on the ground and hanging to the tree; (6) the fungus 

 enters fruits chiefly through wounds, and the curculio is a 

 serious offender in making such wounds. Therefore, remove all 



