JOURNAL OF AOMDm RESEARCH 
Vol. XIV Washington, D. C., July i, 1918 No. 1 
TRUE NATURE OF SPINACH-BLIGHT * 1 AND RELATION OF 
INSECTS TO ITS TRANSMISSION 
By J. A. McCuntock, 2 Plant Pathologist , Virginia Truck Experiment Station , and 
LOREN B. Smith, 8 Assistant State Entomologist , and Entomologist , Virginia Truck 
Experiment Station t 
INTRODUCTION 
For the past 10 or 15 years the greatest annual loss to the truck growers 
in eastern Virginia has been due to the trouble known as “ spinach-blight.'' 
This was supposed to be a malnutrition disease caused by improper fer¬ 
tilization, and previous recommendations for its control comprehended 
the improvement of soil, fertilizer, and cultural conditions. 
The shipments of spinach (Spinacia oleracea) from the eastern Virginia 
trucking region have averaged between 600,000 and 1,000,000 barrels 
annually, valued at $1,000,000 to $1,500,000. Owing to the ravages of 
the blight during the past two years (1916-17) the acreage has been 
materially decreased, and many growers have abandoned the crop 
entirely, while others grow it only on newly cleared land. Spinach is 
second in importance as a truck crop in this region, being surpassed in 
acreage and value only by the potato (Solarium tuberosum ). Spinach is 
grown during the winter, and thus utilizes land which would otherwise 
be idle at that season. 
The conditions which prevail and the losses sustained from spinach- 
blight have been carefully estimated for several years. From the data 
thus collected it appears that blight annually destroys or renders unfit 
for use not less than 20 per cent of the spinach crop. A conservative 
estimate of the annual money loss to the eastern Virginia growers by this 
disease is between $200,000 and $400,000. 
The writers have found that this disease occurs in the spinach-growing 
regions of New York and Ohio under the name “spinach-yellows.” 
Increasing losses may be expected in those States as the disease becomes 
1 The name 14 spinach-blight” is used throughout this paper because this is the name by which this 
disease has been known since its first appearance in Virginia. 
* Collaborator, Office of Cotton, Truck, and Borage Crop Disease Investigations, United States Depart¬ 
ment of Agriculture. 
8 Detailed by the Virginia Crop Pest Commission for the investigation of insects affecting truck crops. 
Vol. XTV, No. i 
(l) July x, 1918 
Key No. Va. (Norfolk)^ 
Journal of Agricultural Research, 
Washington, D. C. 
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