246 '^he Philippine Journal of Science i9i8 



Causal organism. — The causal organism is the same as dis- 

 cussed under the black rot of cacao pods. The mycelium devel- 

 ops primarily internally in the diseased tissues. Little mycelium 

 is produced on the surface, except under excessively damp con- 

 ditions and when diseased portions are put into a damp chamber. 

 The fungus grows well in pure culture and the disease can be 

 readily produced by inoculation. 



Nectria discophora Mont, may be found growing saprophy- 

 tically on dead stems and it may in some cases follow the 

 Phytophthora attack. 



Control. — All diseased stems should be removed well back of 

 the limit of infection. Cankered spots on the trunk should be 

 cut out down to the healthy wood. It is advisable to paint the 

 larger wounds with a coal-tar preparation or with a good white- 

 lead paint. Badly diseased trees should be cut down and burned. 

 The control measures discussed under black rot of cacao pods 

 are equally effective in combating this disease. 



Symptoms. — A die-back of young twigs and limbs is found, 

 but the causal organism has not been determined. Dead twigs 

 and limbs often bear the following fungi : Botryosphaeria minus- 

 cula Sacc, Cyphella holstii Henn., and Ophionectria theobromae 

 (Pat.) Duss. 



DRY SOOTY ROT: LASIODIPLODIA THEOBROMAE (PAT.) GRIFFON ET MAUBLANC 



Symptoms. — This fungus frequently follows the attack of 

 Phytophthora. It may produce a rot of older fruits without 

 the presence of any other fungus attack. The first sign of 

 disease is a blackening about an injury. This blackened area 

 spreads, until the entire pod is diseased. In this stage the 

 disease appears somewhat like the early stages of the Phytoph- 

 thora rot. In the later stages a black sooty mass of spores is 

 produced over the diseased fruit. At first only one portion of 

 the fruit shows this black mass of spores, but finally the entire 

 fruit is covered. Diseased fruits shrivel and become hard 

 (Plate XIX, fig. 2). 



Causal organism. — The black sooty mass is made up of dark 

 brown two-celled spores. Before maturity these spores are 

 one-celled, hyaline, and much-granular. Spores germinate 

 readily in water overnight (fig. 36). A cross section of the 

 diseased pod shows, just below the surface, a series of pycnidia 

 produced in a mass of brown mycelium. The conidia are 



