6 BULLETIN 13870, U. S. DEPARTMENT OF AGRICULTURE 
position of the sugars by heat. As the pigments of the cane consti- 
tute one of the principal sources of color in sirup, the use of a light-/ 
colored cane evidently is desirable for sirup manufacture.‘ : 
__ Because of the recent introduction and wide dissemination of mosaic | 
disease in all of the Southern States, it is likely that the varieties will | 
be radically changed during the next two or three years. None of | 
the varieties how commonly grown is immune to this disease and most | 
of them are severely injured by it. The gradually diminishing yields | 
of cane during the past few years have been attributed in a large meas- | 
ure to the steady and rapid spread of mosaic. Investigations by the | 
Office of Sugar Plant Investigations, Bureau of Plant Industry, have | 
brought to ight a number of varieties that produce well, even under 
the present conditions of disease saturation. These varieties belong } 
to two distinct groups, the Chunnee-Cheribon hybrids and the Chi-| 
nese. Other groups under investigation have given great promise, but 
only these two are available in any quantity. Although they differ in | 
many details, ali of these varieties greatly outyield the varieties now 
erown, owing to their immunity to or tolerance of disease. Much | 
less seed cane is required to produce a stand, and profitable stubble 
crops are produced over a longer period. The labor requirements for | 
planting and cultivating are smaller, but the harvesting cost is some- | 
what greater. All the canes are harder than the old varieties and } 
higher in fiber content. In Louisiana it is freely predicted that by | 
1927 the new varieties will have completely replaced those now in | 
use, and it is likely that a similar revolution will take place in the |} 
sirup sections. This may necessitate minor modifications in the | 
methods of, manufacturing sugar and sirup. 
VARIETIES SUSCEPTIBLE TO MOSAIC DISEASE 
The Lousiana Purple (also called “Red Cane”), which is by far | 
the most extensively grown variety in the sirup-producing sections, | 
owes its popularity primarily to the fact that 1t matures early and 
yields a sirup of excellent quality. Because of its early maturity, | 
the percentage of cane sugar (sucrose) in solution in the juice is | 
relatively high and that of the invert sugar relatively low. Conse- | 
quently sugar tends to crystallize from sirup which 1s bowed thick. | 
The fiavor of sirup from the Louisiana Purple cane is milder than that | 
from many other varieties. The sirup has a tendency to be dark | 
red, partly because of the coloring matter in the cane rind. | 
The Ribben cane (also called “Red Ribbon” or “Louisiana | 
Striped’’) is almost as popular as the Louisiana Purple throughout | 
the cane-sirup sections, and it is more extensively planted in central | 
and southern Florida. Thestaik is striped, wine-red or purple streaks 
alternating with green or yellow. Because of the lighter color of the 
rind, the sirup from this variety is a shade lighter than that from the 
Louisiana Purple. In all other respects the ribbon cane differs very 
little from the Louisiana Purple cane. 
The Crystalina (known also as “‘ White” or ‘‘ White Transparent’’) | 
is closely related to the Louisiana Purple, having almost identical | 
crowing habits, disease resistance, and sirup-making qualities, except 
that it makes a sirup decidedly lighter in color. The stalk is light © 
ereen or yellow, tending toward pink. Because of the light color of 
the sirup made from it, 1t deserves a more extensive trial. 
4 “The juice from purple canes may be 50 per cent darker than that from green canes.”’ F. W. Zerban, 
Industrial and Engineering Chemistry, (1920) vol. 12, no. 8, p. 744. 
