SAND DROWN, A CHLOROSIS OF TOBACCO DUE TO 
MAGNESIUM DEFICIENCY, AND THE RELATION 
OF SULPHATES AND CHLORIDS OF POTASSIUM 
TO THE DISEASE 1 
By W. W. Garner, Physiologist in Charge , J. E. McMurtrEy, Assistant, C. W. 
Bacon, Assistant Physiologist, Tobacco and Plant Nutrition Investigations , Bureau 
of Plant Industry, United States Department of Agriculture, and E. G. Moss, 
Assistant, Tobacco and Plant Nutrition Investigations, Bureau of Plant Industry, 
United States Department of Agriculture, and Assistant Director, Tobacco Branch 
Station , North Carolina Department of Agriculture 
DESCRIPTION OF SAND DROWN AND ITS EFFECTS 
The disease of tobacco which has received the name “sand drown” 
bears no essential relation to true drowning from excessive moisture in 
the soil. On the contrary, as indicated in the name itself, the disease 
is likely to be most severe on deep, sandy soils which never become 
water-logged. The trouble is aggravated by heavy rainfall, as suggested 
by the word “drown;” but, as will be subsequently developed, the 
effects of the rainfall are chiefly those of leaching rather than of the 
presence of the water itself. The dominant symptom is a characteristic 
type of chlorosis in which the yellow as well as the green pigments of 
chlorophyll are affected. Thus, in the affected tissue the color is a 
dull, very pale yellow, and in extreme cases almost pure white. This 
color is readily distinguished from the clear lemon or orange color com¬ 
monly observed in the healthy leaf which has been exposed to darkness 
for a brief period of time or has undergone partial curing. The chlorosis 
begins on the lowermost leaves and at the tips of the leaves affected. In 
advanced stages practically the whole area of the leaf is involved and 
nearly all the leaves of the plant may be affected. The advance of the 
chlorosis is from the tip and the margin toward the base and the central' 
zone of the leaf. Successive stages in the progress of the bleaching effect 
in the leaf are shown in Plates 2 and 3. Sand drown rarely appears in 
the field till the plants have attained considerable size, more commonly 
after topping, so that the leaves usually attain the normal size and shape, 
as is indicated in Plate 1. The veins of the leaf, as well as the tissue 
immediately adjoining the veins, show a tendency to retain the normal 
green color long after-the remaining leaf tissue has become blanched. 
The disease is scarcely less evident in the cured leaves than in the 
green leaves in the field. In the flue-cured district normal leaves when 
properly cured have a bright lemon to orange color, and in other dis¬ 
tricts the colors range through various shades of brown with either a 
* Accepted for publication Sept, i, 1921. Cooperative investigations of the Office of Tobacco Investi¬ 
gations, Bureau of Plant Industry, United States Department of Agriculture, and the North Carolina 
Department of Agriculture. 
Journal of Agricultural Research, 
Washington, D. C. 
aau 
(37) 
Vol. XXIII, No. 1 
Jan. 6, 1933 
Key No. 360 
