Herbicides present the opportunity for peach growers to 

 replace cultivation with an economical minimum tillage 

 practice. 



*************** 



BROWN ROT OF PEACHES, PLUMS, CHERRIES AND OTHER STONE FRUITS 



C.J. Gil gut 

 Department of Plant Pathology 



Brown rot is the most destructive disease of peaches, plums, 

 cherries and other stone fruits in Massachusetts. It causes blos- 

 som blight, spur blight, twig blight, stem cankers and it rots 

 fruit on the tree and after harvest. Some varieties are more sus- 

 ceptible than others. 



Disease Cycle 



Brown rot is caused by the fungus, Monilinia fructicola , which 

 overwinters in cankers, on twigs and branches, and in hanging mum- 

 mied fruit on the tree and in mummies of fruit which fell to the 

 ground and rotted. In the spring, about the time new growth devel- 

 ops and blossoms start to open, the fungus grows on the surface of 

 the cankers and mummied fruit in the tree as a fuzzy graytsh mold 

 and produces large quantities of dust-like spores called c o n i d i a . 



Spores are also produced in spring by the mummies of fruit on 

 the ground - but in a different way. The fungus does not produce 

 spores directly, as it does on cankers and mummies in the tree, 

 but first produces tiny funnel-shaped, mushroom-like fruiting bod- 

 ies - shaped like a champagne glass. The inside of the cup of the 

 fruiting body is lined with spore-forming tissue which produces 

 dust-like spores, called ascospores , which are released into the aii 

 in puffs as tiny visible clouds when conditions are favorable. 



Both kinds of spores, conidia and ascospores, are carried 

 wind and air currents, and splashed by rain to different parts 

 the tree and to other trees where they germinate and grow into 

 tissues when trees are wet during rainy or humid weather - and 

 can happen in a few hours. 



Control 



by 



of 



tree 



this 



For satisfactory prevention and control of brown rot, it is im- 

 portant for one to keep in mind the following facts: 



(1) The source of spores for infection is twig and stem cankers 

 mummied fruit in the tree and mummied fruit on the ground. 

 Sanitation - picking up rotted fruit on the ground and in 

 the trees, and removal of stem cankers - reduces the spore 

 load in the orchard. 



