124 
FLORIDA STATE HORTICULTURAL SOCIETY 
MATAMORAS, MEXICO 
Several hours were also spent at Ma- 
tamoras, acrosse the Rio Grande River 
from Brownsville. Several dozen orange 
trees, apparently all sour seedlings, were 
examined about the town, but no citrus 
canker was found. 
a 
VARIETIES INFECTED AND INJURIOUSNESS 
Citrus canker has now been observed 
on the following varieties and species of 
citrus. The order adopted is according 
to the degree of infection observed. 
Pomelo, or grapefruit, is most seriously 
infected and heads the list. When fruit 
or twigs are not mentioned that simply 
indicates that no observations have been 
made: 
Pomelo—leaves, twigs, fruit; 
C. T.—leaves, twigs; 
Key Lime, or Wild Lime—leaves, 
twigs; 
Navel—fruit, leaves, twigs; 
Sweet orange—leaves, twigs, fruit; 
Satsuma—leaves, twigs ; 
Tangerine—leaves; 
Mandarin—leaves; 
King orange—leaves ; 
Lemon—leaves, twigs ; 
Kumquats—appear to be immune. 
The greatest danger from this disease, 
for Florida, lies in the fact that it is prin¬ 
cipally a pomelo disease. As already 
stated, it attacks the twigs of these trees 
viruently, resulting in a putting out of 
more twigs, thus overloading the trees 
with small branches. It is also virulent in 
the manner in which it affects the leaves, 
spotting them, causing them to turn yel¬ 
low and dropping prematurely. The 
worst of it, however, is the manner in 
which it affects the fruit. Judging by 
the few fruits that have come under ob¬ 
servation, it appears safe to estimate that 
at the very least one-half of a grapefruit 
crop would be made unmarketable or re¬ 
duced to culls, although probably not 
ruined for eating, as the cankers are only 
skin deep. It requires no extensive 
mathematical knowledge to discern that 
this disease may cause losses aggregating 
millions of dollars, if not eradicated. 
It must be admitted, on the other hand, 
that, after all, we may know but little 
about the effects of this disease. There 
has been no opportunity to observe it in 
larger trees bearing considerable quanti¬ 
ties of fruit. The fruit available was 
sent in by correspondents, and the writer 
himself found only one small specimen 
of grapefruit in the nursery at Monti- 
cello, but all of these had dozens of can¬ 
kers on the skin. The pomelo trees at 
Grand Bay, Wiggins, and Alvin had no 
fruit on them at the time of examination. 
While it is quite apparent that oranges 
are far less susceptible, it is also appar¬ 
ent that a large percent would become 
spotted and have to be sold as culls. The 
few fruits on a sweet orange tree at 
Port Arthur, Texas, previously referred 
to, indicate this. 
ORIGIN OF CITRUS CANKER. 
The evidence at present indicates defi¬ 
nitely that it was imported from, Japan 
on C. T. seedlings, and probably on other 
citrus. K. Saibara, of the Saibara Nur¬ 
series, Mobile, Alabama, stated that he 
saw the disease first, in 1911, on trees 
imported from Japan and planted in Tex- 
