128 
Journal 0} Agricultural Research 
Vol. XXIII. No. x 
reddish or a greenish cast. On the other hand, the leaves or the por¬ 
tions of leaves affected with sand drown show after curing a dull, faded 
appearance similar to that observed in the diseased leaves in the field. 
Since color is of great importance in determining the commercial value 
•of most types of tobacco, it is easily seen that sand drown may 
greatly lower the market price of the affected leaves. This applies 
with special force to the sale of cigar-wrapper leaf. Moreover, sand 
drown greatly reduces the weight of the cured product; in fact the 
affected parts of the leaf are remarkably thin after having been cured. 
For example, in a test with flue-cured tobacco the normal leaf was 
found to be 45 per cent thicker and 65 per cent heavier per unit area 
than the diseased leaf. As would be expected, the tissue of diseased 
leaves is dry and lifeless. Thus, sand drown affects unfavorably the 
color, weight, body, and elasticity of tobacco leaf. 
OCCURRENCE OF SAND DROWN 
The disease first came under observation about 1912 at the Tobacco 
Station of the North Carolina Department of Agriculture located at 
Oxford, in connection writh the cooperative investigations in progress at 
that point. The same trouble also was seen on some of the farms of 
tobacco growers in the vicinity. It has appeared each year on the 
tobacco grown at the Oxford station, but it soon became apparent that 
weather conditions and the kinds and quantities of fertilizers applied 
affect in a marked degree the appearance and course of the disease. In 
general, it may be said that with approximately normal rainfall and the 
use of fertilizers of the grades and the quantities that have been most 
widely employed in tobacco culture sand drown is not commonly seen 
in sufficiently severe form to attract attention or to cause serious loss. 
On the other hand, the malady is likely to be widespread in seasons of 
heavy rainfall in those sections in which the dominant soil types are 
distinctly sandy in character. For example, this type of chlorosis is 
frequently seen on the more sandy tobacco soils of the Connecticut 
Valley in excessively wet seasons. As will be pointed out, the use of 
Certain fertilizer salts will lead to symptoms of sand drown even in sea¬ 
sons of normal rainfall and on the heavier types of soil, although it 
remains to be determined just how generally this action may be observed 
under varied soil and weather conditions. It is possible, also, that 
material injury to the color and other properties of the cured leaf may 
result from mild forms of the trouble which would not be clearly recog¬ 
nizable in the field. In pot cultures sand drown can be easily induced 
and cured at will. 
RELATION OF SULPHATES AND CHLORIDS TO SAND DROWN 
As a feature of the cooperative investigations at the Oxford (N. C.) 
Tobacco Station, fertilizer plot tests have been in progress for several 
years in which various forms and rates of application of nitrogen, phos¬ 
phoric acid, and potash are compared. The soil is classed as Durham 
sandy loam and is not fertile. Sand drown has frequently appeared on 
the test plots. On most of the plots the tobacco has been fertilized with 
sulphate of potash in combination with other materials, and it was 
observed that increase in the rate of application of the sulphate clearly 
increased the severity of sand drown in the tobacco. On plots receiving 
