234 Nebraska State Horticultural Society, 



SCAB OR BLACK SPOT. 



(Cladosporimn cai"pi>pliiluin) . 



This disease does the most damage to peaches, tho plums are also 

 attacked. The fungus may cause a shot-hole effect of the leaves, tha 

 its chief injury is to the fruit. Black spots are formed on the surface 

 of the fruit, and growth of the skin is retarded so that the fruit often, 

 cracks open. 



TREATMENT. 



Raking up the dead leaves, destroying the infested fruit, and 

 spraying at the same time as for leaf-curl, are recommended. 



BROWN ROT (Monilia f ructigena ) . 



The dark brown, mummified fruits, covered with light gray spore- 

 tufts, which are the work of this fungus, are well known to all growers 

 of stone fruits. Blossoms, and in the case of the plum and peach, stems 

 and leaves, are also killed by it. The fungus is primarily a saprophyte, 

 and unless conditions are very favorable it does not cause serious in- 

 jury to strong, vigorously growing tissue. The fruit is seldom attacked 

 until it is nearly ripe, and are destroyed much more readily after, re- 

 moval from the tree than before; when blossoms are attacked infection 

 is most likely to take place on the calyx at the time the petals fall, and 

 the rapidly growing pistil of the flower which has successfully "set" 

 often defies Infection until the stem below it is rotted, so that its growth 

 has to cease. Infection of peach and plum twigs results f ) om the 

 mycelium in the blossom growing on into the stem; it there attacks 

 the tissues, and after the rest of the stem is weakened because of the 

 Impaired transport the fungus invades the whole stem and leaves be- 

 yond the point of infection. The most harm is done in this vicinity by 

 the destruction of plum blossoms and the rotting of peaches and plums 

 on the tree; the difficulty in keeping stone fruits any length of time 

 after picking is also largely due to this fungus. Even apples are seri- 

 ously bothered in some localities. 



