gQg The Philippine Journal of Science 



Table 1 shows the control inoculations to have remained 

 entirely healthy, while the inoculations with the fungus infusion 

 produced twelve cases of the disease from a total of twenty-four 

 attempts. That is, 50 per cent of the inoculations with the 

 fungus resulted in positive cases of the disease. 



The inoculations were then repeated upon fruits still remain- 

 ing on the tree under orchard conditions. Of thirty such in- 

 oculation attempts made under orchard conditions with the 

 Gloeosporium fungus, ten positive cases of the disease resulted. 

 The inoculations in this case were made with needle punctures, 

 the only difference between this series of inoculations and those 

 reported in the preceding table being that the inoculations in 

 the orchard were made at normal air humidity while those 

 reported in the table were made at an artificially maintained, 

 high humidity. Control inoculations made with tap water and 

 needle punctures again yielded entirely negative results. The 

 Gloeosporium fungus was again reisolated from the inoculations 

 resulting positively, and upon reinoculation upon Wase fruits 

 again produced the disease. Inoculations have since been made 

 repeatedly with positive results in reasonable percentages of 

 cases. The postulates of Koch have thus been fulfilled, and the 

 inoculation experiments lead to the statement that the disease 

 of Wase Unshiu orange fruits is caused by this fungus of the 

 genus Gloeosporium. The fungus was subsequently isolated 

 from affected fruits obtained at Tsukumi. To the present time 

 three different series of inoculations with this Gloeosporium, 

 without punctures, have failed to reproduce the disease, indi- 

 cating that the fungus is dependent upon wounds or bruises for 

 entrance. 



IDENTIFICATION OF THE FUNGUS 



The fruiting bodies of the fungus occurring both naturally on 

 diseased fruits and in culture are the typical Gloeosporium acer- 

 vuli. The masses of spores resulting on the fruits are most often 

 black en masse, but in fresh cultures are usually pink. The 

 individual conidiophores are often branching as shown in figure 

 1 and are characteristically tapering at the tip. The spores 

 when newly formed are elongate, slightly tapering to the ends, 

 and the ends are usually rounded. In old cultures the spores 

 may assume a number of eccentric shapes. When newly formed 

 the spores are hyaline and few or no granular bodies are to be 

 seen. Spores from old cultures, however, become something of 

 an olive shade and are very granular; one or two vacuoles are 



