222 DISEASES OF TROPICAL PLANTS 



CH. 



spores. When mature and when brought in contact 

 with water, these spores pour out and are carried to 

 other plants. The treatment recommended for " damp- 

 ing off" would no doubt prove a valuable remedy for 

 this disease. 



Leaf Spot. This disease (Fig. 76) attacks the foliage 

 of plants of all ages, and also the fruits. It produces 

 characteristic leaf spots, in the centre of which are a 

 great number of small black specks. When the foliage 

 is badly diseased the vitality and fruitfulness of the 



FIG. 76. Egg-plant leaves affected with leaf spot, Phyllosticta Iwrtorum. 



plant is reduced. When the fruits become diseased 

 their market value is practically destroyed. This 

 disease, which is caused by Phyllosticta liortorum, has 

 been reported from Cuba, and no doubt has a very 

 much wider distribution throughout the American 

 tropics. It is especially severe in wet weather, and is 

 very common on the fruits, causing them to decay. It 

 is especially severe on fruits which have suffered from 

 mechanical injuries or from sun scalds. This disease 

 can be controlled by the use of Bordeaux mixture. 



Stem Rot. A stem rot due to Nectria ipomoeae, 



