S26 
Journal of Agricultural Research 
Vol. XXVIII, No. 8 
Protection and shading of some of the affected plants would determine the 
•extent to which the crazy-top symptoms are modified by the condition of growth* 
and whether mosaic discolorations can be induced by shading, as in the case of 
the potato mosaic under high-altitude conditions. By means of insect-proof 
cages, the relation of the disease to insect carriers may be demonstrated, or 
plants inoculated artificially to study the conditions of infection. 
CONCLUSIONS 
Abnormal behavior of cotton plants, resulting in partial or complete sterility 
of the affected individuals, is of frequent occurrence in Arizona, and is known 
Among the farmers as “crazy-top.” The name acromania is suggested as a 
technical designation for the crazy-top disorder, both names alluding to the 
Abnormal branching in the upper portion of the plant, which is a striking feature 
of this disorder. The recognition of acromania as a distinct disorder has re¬ 
sulted from previous study of other disorders which are to be compared and 
distinguished from acromania. 
Crazy-top has been ascribed to exhaustion of the soil and to a supposed 
*' ‘running-out” of the Pima variety, but these theories are plainly inadequate. 
Although the crazy-top symptoms are more striking and the injuries are greater 
where the cultural conditions are less favorable for the plants, the disorder is 
not restricted to Pima cotton or to particular types of soil, or to lands that have 
grown cotton in previous years. 
The crazy-top injuries are more severe in Upland cotton and the symptoms 
more numerous. In addition to the abnormal branching and sterility, as in 
Pima cotton, a wide range of diversity is shown in crazy-top plants of Upland 
eotton, with many forms and degrees of reduction and distortion of the leaves, 
involucres and floral organs. Also, the Upland cotton apparently does not re¬ 
cover or return to more normal behavior late in the season to the same extent 
as Pima. 
The reduction and distortion of the leaves and complete sterility of the top 
growth in Upland cotton are similar to the cyrtosis and stenosis disorders in 
China and Haiti. Hence a comparison of crazy-top symptoms with those of 
other growth disorders, including the mosaic diseases, seems justified, although 
the characteristic feature of mosaic diseases, the mottled discoloration of the 
leaves, is not present in crazy-top. The less striking effects of crazy-top in Pima 
•cotton, as well as the variation of symptoms and injuries under different con¬ 
ditions, also are paralleled in cyrtosis and stenosis. 
Although the late-season growth of affected plants is less abnormal than the 
growth at mid-season, crazy-top apparently is a disorder resulting in permanent 
injury like cyrtosis and stenosis, instead of a disorder causing temporary injury 
like tomosis and hybosis. 
The change in the branching habit results from the fact that the fruiting 
branches of the upper part of the plants are partially or completely transformed 
or replaced by vegetative branches. Partial transformation is the more fre¬ 
quent condition and is shown by the abortion of the floral buds at very early 
stages, leaving a minute bud scar on each internode of the branch. 
Association of the crazy-top disorder with the mosaic diseases is suggested 
by the similarity of symptoms and modes of occurrence, and further knowledge 
may lead to the discovery of measures of restricting the injuries. The variable 
and sporadic occurrence of the disease may be explained if it is found that the 
infection is carried by insects from some of the native wild plants or weeds that 
are related to cotton. By determining the source of infection it may be possible 
to protect the cotton fields against the crazy-top disorder, or to avoid the injurious 
offects in other ways. 
