10 BULLETIN 1765, U. S. DEPARTMENT OF AGRICULTURE. 
sick land and the adaptability of resistant Burley to it. The be- 
havior of the resistant strains as compared with the ordinary Burleys 
on the farm of Mr. William Feck is shown in figure 4. It does not 
follow, nor is it recommended, that continuous culture of Burley 
tobacco should be practiced in the Burley section. On small farms 
or where suitable soil is scarce it may be highly desirable to grow 
tobacco on the same land more frequently than hitherto has been 
possible. The important point, however, is that the number of to- 
bacco crops which may be grown on a given piece of land usually is 
not sharply limited by lack of fertility, but rather by disease. The 
value of resistant strains, therefore, lies in reducing the chances of 
poor yields in second or third crops on soils gradually becoming sick. 
Fic. 4.—Resistant White Burley tobacco (on the right) and ordinary White Burley strains 
(on the left) growing on the farm of William Feck, Lexington, Ky., in 1917. The 
tobacco was about half grown when the photograph was taken. 
With respect to the quality of the resistant Burley, considerable 
evidence is at hand to show that so far as market value is concerned 
it has not proved to be inferior to the ordinary strains. Some of the 
growers who tried this seed in 1917 on a small scale planted as many 
as 10 or 15 acres in 1918. The final reports as to the quality of the 
1918 crop are not yet obtainable, but there is no reason to believe 
that its average value will be less than that of ordinary Burley, 1. e., 
the Kelly, Halley, Big Stand-up, and other strains. 
RESISTANT BURLEY STRAINS RECOMMENDED FOR SICK SOILS 
IN WHITE BURLEY DISTRICTS. 
Until stand-up Burleys of unquestionable perfection in quality are 
obtained it is believed that growers can very profitably plant the re- 
sistant drooping-leaved variety of Burley where it is desired to utilize 
sick soils. It is recommended that those who are putting in second 
