RUBBER iHEVEA, DISEAf 43 
with the usual shot-hole effect (PL XVII. B). The leaves were 
sometimes so excessively perforated that little of the uninfected 
tissues remained. 
Fusarium heveae and immature stages of Diplodia theobromae 
followed on these spots when old. 
The forms of infection involving a part of the entire leaf surface 
were of less frequent occurrence, but were usually more destructive. 
WHITE OE GRAY LEAF-.-: 
On mature leaves grayish or whitish areas extending back from 
the tips or edges but rarely completely surrounding the lea: 
scattered over the surface as irregular spots and in all cases larger 
than shot-hole were of common occurrence. The infected 
usually remained intact and did not fall away to form holes, A 
Gloeosporium forming brown spore masses was always found asso- 
ciated with this disease. The organism is referred to Gloeospm 
heveae. The diseased tissues became white and bleached when old. 
Diplodia then either appeared on these areas while on the tree or 
after the leaves had fallen. 
RIM-SPOT 
Another form of leaf-spot with which Gloeosporium was a 
ciated was that of pale-brown or yellowish spots in a zone near the 
edge of nearly mature leaves. These -pots may later coalesce to 
form a brown margin for a part of the distance around the leaf. 
The discolored area, however, is of a lighter color than that in 
rim-blight. The tissues remained their original color and did not 
bleach out or fall from the leaf. Brown spore masses appear in the 
center of the spots, which agree with Gloeo*po>-i>.Uf / The 
disease was observed at two different stations on young trees about 
5 feet high and did not appear to be of much importance. 
BLIGHT OF YOF/A'G LEAVES 
The most important leaf disease fur which Gloeosporium appar- 
ently is solely responsible took the form of a complete infection of 
the entire surface of young leaves. Appearing first as irregular 
watery spots along the margin or at the tips, the areas soon spread 
to the petioles and infected and killed the tips of the branches. The 
leaves soon became uniformly infected and turned greenish black, 
resembling the conidial infection of Dothidi ^The fructifica- 
tions of the fungus appeared on the lower side of the leaf along the 
veins or midrib, at first as slightly grayish patches, becoming pink- 
ish and fading when dry. The fungus may be referred to 
Gloeosporium aZborubrum. 
The disease was first observed in a patch of young seedli 
growing in wet soil and had the appearance of a serious parasite. 
Some 20 or 30 plants had succumbed to the disease. This result, 
however, may have been intensified by unfavorable growth condi- 
tions and would not occur in plants of high vigor. 
It would appear that the type of infection is influenced by the 
age of the leaf. 
