CITRUS MELANOSE AND ITS CONTROL 11 
In Brazil, the West Indies, and California melanose is reported to 
occur in negligible quantities, whereas in Texas, Louisiana, Missis- 
sippi, and Alabama the disease is said to be sporadic in its behavor; 
sometimes it occurs in serious proportions, but generally it is slight. 
LOCAL DISTRIBUTION IN FLORIDA 
Although citrus melanose occurs in varying proportions through- 
out the citrus regions of the Gulf Coast States, the disease occurs at 
its worst in central Florida, where it is regularly a serious disease, 
varying in intensity from locality to locality, and somewhat from 
year to year. Melanose is generally distributed throughout the citrus 
belt of Florida, where it is a serious disease in most of the old citrus 
districts and is becoming gradually more serious where it has hereto- 
fore occurred in minor amounts. Wherever the groves are relatively 
young the disease is not usually serious, but it is becoming progres- 
sively more abundant with the increasing age of the plantings, and 
special measures are being taken to control it. In flatwoods, ham- 
mocks, or other low and damp locations citrus melanose occurs in 
abundance, and many of the older groves of Florida are set in such 
locations. It has not been found to be severe on wild citrus growing 
in densely shaded hammocks, where the citrus trees grow very slowly 
but have a healthy color of foliage. In many instances the disease 
is more pronounced in inland sections than close to the seashore. 
Melanose has not yet become a chronically serious disease in the 
extreme southern citrus districts of the State, although it caused an 
enormous damage in that general territory following the freeze of 
1917. This is strong evidence that if conditions are favorable for 
outbreaks citrus melanose should be expected to become a serious 
menace, for a limited time at least, in any fruit district in southern 
Florida. In the northern part of the citrus belt of Florida, especially 
where there is occasional damage by freezes, it becomes especially 
severe following cold winters. 
Figure 1 shows the principal regions of melanose infection, which 
coincide roughly with the districts where the round orange and the 
grapefruit are grown commercially. In the northern and western 
parts of the State extensive developments in Satsuma planting are 
taking place, but the industry has not become stable there, and for 
that reason they are not shown on this map, although melanose occurs 
there to some extent. 
It will be seen from this map that melanose is an important disease 
throughout the entire round-orange and grapefruit belt. On the 
high, dry lands through the central part of the peninsula where most 
of the groves are relatively young and along the lower east and west 
coast the disease has not yet become generally serious. 
ECONOMIC IMPORTANCE 
In general importance to the citrus industry of the world, citrus 
melanose appears to be of minor significance, but it is a major factor 
to the citrus industry of Florida. In the districts where the disease 
occurs in quantity, citrus melanose, together with the Phomopsis 
