2 BULLETIN" 829, U. S. DEPARTMENT OF AGRICULTURE. 
of the interior throughout these regions. Its progress eastward was 
slower, but at the present time more than three-fourths of the cane 
fields of the island are invaded. 
During the last 12 months, methods of control have been put 
into operation which have undoubtedly aided in checking the spread 
of the disease into new territory. It has appeared sporadically at a 
few points in the eastern fourth of the island, but the planters, 
thoroughly aroused and alert, have not permitted it to spread there 
as it has in the west. It has become the practice to inspect the 
fields regularly and eradicate diseased individual plants as they 
appear, thus removing the source of infectious material. This 
method has been successful where only a small percentage of the 
plants are infected. In the west, where 75 to 100 per cent of the 
plants in commercial fields are diseased, this method naturally can 
not be recommended. The average reduction in output of sugar 
for 10 mills in the worst infected area has been nearly 40 per cent, 
notwithstanding an increased acreage in cane, while the average 
output for 10 mills in the disease-free area shows a slight gain for 
the same period. These figures are approximate, but they indicate 
clearly the gravity of the situation. 
The disease is not new, but was recognized as an undesirable 
condition in sugar cane as early as 1890 in Java, where it is called 
gele strepenziekte, "yellow stripe." 1 Owing to the failure of Dutch 
investigators to secure infection by artificial inoculation, they did 
not regard the disease as infectious, but rather as frequently recur- 
ring bud variations. This view was undoubtedly due to the fact 
that it had for years been present, but unnoticed and unrecorded as 
a specific disease, so that during this long period unconscious selec- 
tion had eliminated all but the more or less resistant but not immune 
varieties of cane. Thus, where the disease had become endemic it 
would be especially injurious only to varieties imported from coun- 
tries where the disease did not exist. It would be difficult to carry 
on successful infection experiments where the disease is as prevalent 
as it is in Java. 
Dutch investigators reported the presence of yellow stripe in 
Egypt in 1909 on cane imported from Java and in the Hawaiian 
Islands in 1910. In the latter territory nearly all cane regions have 
become infested, and careful experiments have shown that where all 
plants in a field are attacked, according to Table I, it causes a reduc- 
tion in yield of sugar of 5 to 40 per cent, depending upon the variety 
of cane. 
i Wilbrink, G.,|and Ledeboer, F. P^drage tot de kermis der gele strepenziekte. Meded. Proefstat. Java- 
Suikerindus., No. 39,2, p. 443-495, 5 pi. (4 col.), 1910. 
