34 6 Diseases of Truck Crops 



The greatest amount of rotting occurs within the 

 fruit. 



The Organism. The parasite is a typical yeast. 

 It produces arthrospores of non-gametic origin, asci 

 of gametic origin (fig. 65 a-c). The ascospores are 

 formed in two groups of four each, slender, one- 

 septate, and each containing a motionless flagellum. 

 Little is known about the control of this disease. 



Fruit Rot 



Caused by Phoma destructiva Plowr. 



Fruit rot is found in Cuba, Florida, South Carolina, 

 Kansas, and New York. If not checked, it will no 

 doubt spread rapidly and add to the burdens of losses 

 from other troubles. 



Symptoms. On the fruit the disease is charac- 

 terized by conspicuous dark spots (fig. 65 e) on the 

 side and at the stem end of both green and mature 

 fruit. On the surface of the largest spots numerous 

 dark pycnidia may be seen. Besides attacking the 

 fruit, the disease may also attack the foliage, causing 

 dark spots which resemble those on the fruit (fig. 

 65 d). Affected leaves shrivel, droop, and sometimes 

 drop off. The disease seems to be unable to attack 

 potatoes or peppers. 



The Organism. The mycelium (fig. 65 h) forms a 

 dense network of fungal threads within the host 

 tissue. The pycnidia (fig. 65 g) are subglobose, car- 

 bonaceous, smooth, slightly papillate, and with a dis- 

 tinct central pore. The pycnidia are scattered and 



