May 24,1924 
Acromania, or u Crazy-Top” 
811 
China. The smalling disease was seen in July, 1923, in the vicinity of St. Michel, 
in the north-central part of Haiti. In some of the fields all of the plants appeared 
to be affected, while in other fields only scattered individuals showed the disease 
while the intervening plants had continued to grow normally through the season. 
In some cases it appeared that plants had become affected at different stages 
of growth, as indicated by the extent of the top-growth that had occurred after 
the incidence of the disease (8 ). 
On account of the reducing effect of this disease in Upland cotton, the con¬ 
trasts between the normal and abnormal growth are most striking. Also, there 
may be a very wide range of diversity in the abnormal growth of different individ¬ 
ual plants in the same field of cotton, not only in the extent of dwarfing but in 
many other features of the abnormal growth, including the abilitj^ to produce 
flowers or bolls. The abnormal growth of many of the plants is completely 
sterile, either by suppression of flower buds or by abortion of the buds at very 
early stages. In other plants the flower buds may develop to larger sizes, or 
the flowering stage may be reached. Some plants produce many undersized 
flowers but set no bolls, or on some of the less injured plants bolls may be retained 
and grow to nearly normal size. 
In the examples of stenosis shown in Plate 9 the abnormal growth began very 
abruptly, with the leaves and other organs suddenly restricted to very small size, 
after producing normal leaves at the lower nodes of the same stalks. One of the 
plants had grown less than three inches in height after the disorder began, though 
small branches from several nodes along the stalk showed the same dwarfing and 
other abnormalities as the top-growth. The other plant was less seriously 
affected, and retained its squares to larger size. The zigzag form of the stalk in 
this specimen is one of the many peculiarities that contribute to the diversity of 
the abnormal top-growth of the affected plants. 
No indications of recovery from stenosis were observed, even in fields where 
the disease had remained limited to scattered individual plants that must have 
been infected several weeks before, as shown by the amount of abnormal top- 
growth that had developed. The absence of more recent infections would seem 
to show that the insects or other agents of infection were no longer present in the 
fields. Later plantings of Upland cotton, in July and August, 1923, were reported 
in November to have shown no indication of being affected with the disease. 
The mosaic discoloration of the leaves, though generally appreciable in stenosis, 
is a less prominent feature than in cyrtosis, while the reduction or dwarfing of 
leaves and other organs is carried much farther, especially in Upland cotton. On 
account of the extreme dwarfing of the new growth in some of the affected plants, 
the range of variation in the symptoms appeared much greater in the stenosis 
disease in Haiti than in the cyrtosis disease in China. 
The Sea Island type of cotton was represented by occasional plants in some of 
the fields and appeared to be much less affected than the Upland cotton, as had 
been observed also in China. The Bourbon or “Native Haitian” cotton did not 
appear to be injured at all by stenosis, though it may be tolerant of the disease, 
rather than immune. That the disease may be carried in the Bourbon cotton 
is indicated by a statement of G. G. Burlingame in April, 1924. A later planting 
of Upland cotton at St. Michel, Haiti, adjacent to a block of Bourbon cotton, 
showed a large proportion of diseased plants in the rows next to the Bourbon 
cotton, and gradual reductions in the number of diseased plants in the rows 
farther away. 
96038—24f-8 
