19, 4 Reinking and Groff: Siamese Seedless Pummelo 423 
trees are vigorous. In neglected orchards it is not so much in 
evidence. Counts of cankered fruits of the Nakorn Chaisri 
seedless variety in storage give some indication of the severity . 
of the disease. Of 128 fruits examined, 74, or 58 per cent, were 
found to be more or less severely cankered. Young plants, 
introduced and growing under Philippine conditions, at the Col- 
lege of Agriculture, Los Bajios, are badly affected. 
Epiphytes; parasitic; Loranthus species. The most serious 
trouble on citrus trees in general is caused by Loranthus, of 
which the following species were found to attack the Siamese 
pummelo: Loranthus ferrugineus Roxb., L. parasiticus (Linn.) 
Merr., and L. pentandrus Linn. If the epiphyte is not cut out, 
it soon envelops the entire tree. The parasite has a wide range; 
it is found on mangos, mangosteens, and durians, and on the 
native tree Bruguiera sexangula (Lour.) Poir. that is used to 
line dikes. Care should be taken to remove the epiphyte from 
all trees affected. 
Fruit rot; Diplodia. Fruits in storage or those that have 
been allowed to decay on the ground are frequently subject to 
a black rot caused by a Diplodia (Plate 15, fig. 1). The trouble 
is not serious. It is not common on fruits on the trees or in 
storage. Rough handling in picking and storing makes the 
fruits more susceptible to rot. All black-rotted fruits should be 
collected and burned, as the fungus causing the disease is the 
same that produces bark rot and gummosis. 
Fruit rot; Sclerotium. A Sclerotiwm may cause rot on fruits 
that have fallen to the ground. The disease is characterized 
by the formation of small, spherical, brownish, sclerotial bodies 
over the decayed area. 
Gummosis; Diplodia. Gummosis may be severe in neglected 
orchards. It is of two kinds, that due to a Diplodia and that 
due to malnutrition. 
Lichens; undetermined. Lichens of various sorts are found 
on trunk, branches, leaves, and fruits. Little damage is done 
by them. 
Mottled leaf; nonparasitic. A typical mottled leaf with the 
yellowed areas between the green veins is common, but is not 
considered serious. 
Russet; undetermined. Fruits may be russety. Whether 
this is due to injury caused by rubbing against branches or to 
fungi could not be determined. In some cases the disease ap- 
peared to be typical, due to the wither-tip fungus Colletotrichum 
gloeosporioides Penz. 
