748 
The Philippine Journal of Science 
1921 
blotch, giving the leaf a mottled appearance. This type of 
lesion is found on both old and young leaves. 
Later the tissue in the central portion of the lesion dies and 
turns grayish brown or dirt colored. This central area is always 
surrounded with a band of yellow, chlorotic tissue, from 1 to 
2 millimeters wide. 
The growth of the lesion seems to be definitely limited, for 
when the development has ■ progressed to a certain point the 
tissue, both dead and chlorotic, falls out and leaves a shot-hole 
condition. After this shot-holing has taken place the leaf, if it 
is not too severely parasitized, lives and carries on to a greater or 
less extent its photosynthetic function. 
A yellowing of the tissue develops with the more severely 
spotted leaves. This, in turn, is followed by defoliation which 
seems to be very serious in the present attack. 
Black lesions form on many fruits, causing no noticeable dam- 
age, however. Many such lesions have been examined, but 
their connection with the Cercospora leaf spot has not been 
established. This connection, nevertheless, seems probable. 
HOSTS ATTACKED 
A related species, Averrhoa bilimbi Linnaeus, also pantropic, 
is grown in great abundance locally. Many trees have been ob- 
served, but no leaf spot caused by Cercospora has been found. 
The attack of the fungus seems to be confined to Averrhoa 
carambola. 
ECONOMIC IMPORTANCE 
The trees grown at the College of Agriculture number about 
forty. The fungus under discussion is found on each tree and 
causes no small loss. The leaves, which are more than half 
mature, show 100 per cent infection, with several lesions on each 
leaf. The trees which have been left uncontrolled have been 
nearly defoliated. If defoliation is repeated the loss of the trees 
is imminent (Plate 1). 
CAUSAL ORGANISM 
The organism that causes the leaf spot of Averrhoa carambola, 
discussed in this paper, belongs to the genus Cercospora. 
The fruiting bodies, consisting of conidiophores and conidia, 
are born in the grayish brown central portion of old lesions. 
They occur on both sides of the leaf, but more abundantly on the 
lower surface. 
