19,6 Welles: Leaf Spot of Averrhoa Carambola 749 
The conidiophores are produced in clumps which arise in sto- 
matal openings. They are light brown, simple, erect, and are 
3- to 7-septate. The average conidiophore measures 52.51 ^ long 
and 5.04 ju wide, the extremes being 61.64 to 47.84 /x long and 5.52 
to 4.41 jx wide. 
The conidia are hyaline, short, straight or slightly curved, 
erect, larger at the basal end, and taper slightly to a blunt 
point. The average conidium measures 45.26 /x long and 
4.23 fx wide, the extremes being 67.52 to 27.96 /x long and 5.2 
to 2.8 /x wide. They are 4- to 7-septate. 
CULTURAL CHARACTERISTICS 
Isolation is easily accomplished by plating the diseased tissue 
directly on com meal medium. The mycelium develops with 
moderate rapidity. 
At first the mycelium appears in a very thin growth. Later 
it develops into a rather thick mass of closely packed hyphae. 
With age the central portion of the mycelial growth turns gray- 
ish green and is surrounded with a thin band of white mycelium. 
The cultures have been kept for but a short period, so no fruit- 
ing bodies have developed. 
CERCOSPORA AVERRHOI sp. nOV. 
Conidiophores light brown, simple, erect, 52.51 by 5.04 /x, the 
extremes being 61.64 to 47.84 by 5.52 to 4.41 /a; tufted, arising 
from stomatal openings, on both surfaces of the leaf but more 
commonly on the lower surface. Conidia hyaline, short, straight 
or slightly covered, erect, 4- to 7-septate, average measures 
45.26 by 4.23 /a, the extremes being 67.52 to 27.96 by 5.2 
to 2.8 /X. Readily cultured on starchy media, producing first 
thin, white hyphae, with age becoming thickly matted and 
grayish green; spores not commonly produced in culture. 
On leaves of Averrhoa carambola Linn., causing amphigenous, 
circular or irregular, grayish brown spots with yellow borders, 
3 to 5 millimeters in width; at Los Banos, Laguna Province, 
Philippine Islands. 
CONTROL 
Control experiments with Bordeaux mixture were commenced 
on July 13, 1921, about the beginning of the rainy season. The 
Bordeaux mixture was made up according to the following for- 
mula: 1.8 kilograms copper sulphate, 2 kilograms stone lime, 
190 liters of water. 
