BREEDING RESEARCH FOR 
IMPROVED DISEASE RESISTANCE, 
YIELD AND QUALITY 
By 
C. H. RoGers, Ph.D., Plant Pathologist 
During the past quarter of a century the breeding 
efforts of Coker’s Pedigreed Seed Company to in- 
corporate and stabilize excellent growth and smoking 
qualities in flue-cured varieties of tobacco have con- 
tributed to a notable improvement in the appear- 
ance, yield and quality of the crop of the Bright Belt. 
Tobacco breeders of the Company have screened and 
utilized all available material in advancing this pro- 
gram. 
PLANT DISEASES—A MAJOR PROBLEM OF 
TOBACCO GROWERS 
The occurrences and rapid spread of virulent dis- 
eases such as black shank, Granville wilt and Fusa- 
rium wilt, together with the universal presence of 
root infesting nematodes has intensified the breeding 
of tobaccos which will withstand losses from these 
diseases that, all together, amount to 15 per cent or 
more of each year’s crop, or nearly $100,000,000 an- 
nually. Included in our breeding material are re- 
selected lines from standard varieties, crosses or 
hybrids between these varieties, and crosses between 
varieties and non flue-cured types that carry resist- 
ance to one or more diseases. For example, fairly high 
resistance, or tolerance, to black shank is obtained 
from a cigar wrapper type. In other cases, resistance 
to one or more specific diseases has come from in- 
troductions from foreign countries. Some of this ma- 
terial has been furnished by State or Federal agen- 
cies. 
DISEASE BREEDING WORK RECEIVING 
MAJOR EMPHASIS 
Selected plant material from hundreds and thou- 
sands of crosses has been rigidly tested on the most 
severely disease-infested soils available. Continued 
selecting and crossing is done not only to work toward 
high disease resistance, but to improve yield and 
smoking qualities. Our nurseries include hundreds 
of kinds (or lines) and, within these, thousands of 
plants are bagged each year to prevent unknown 
crossing. Primings are taken from individual plants 
and tagged and cured to evaluate quality of leaf as 
it would be placed on the warehouse floor. Advance 
material that shows disease resistance and improved 
quality is placed in replicated comparative yield 
trials. Before releasing a new variety of tobacco to 
growers, it is tested for at least three years under 
such conditions, and is also grown on different farms 
[3] 
Dr. C. H. Rogers, author of this article, is shown here studying an 
individual plant selection of Coker’s Golden Cure, our newest tobacco variety. 
over a wide area in the flue-cured belts. In coopera- 
tion with one of the leading manufacturers, our most 
promising tobaccos are subjected to chemical analy- 
sis and processing to determine cigarette manufac- 
turing qualities. 
BLACK SHANK 
We are emphasizing particularly the breeding 
work on black shank and are utilizing three different 
severely infested locations, as well as plots artificially 
inoculated with the disease. Greenhouse facilities 
are also used to hasten breeding for high resistance 
to this disease. We hope that within about two or 
three years we shall be able to offer to the grower 
a variety, or varieties, derived from this black shank 
breeding work. 
Our present program includes over 2,000 varietal 
and hybrid lines in 10 nurseries at Hartsville, and 
other locations in North and South Carolina, on 
severely disease-infested soil; 45 advanced lines or 
varieties in comparative yield and quality tests, and 
12 varieties for current sales stock. 
Our aim is to incorporate resistance to the major 
diseases, high yield, and top smoking quality in 
single varieties of tobacco that are well adapted to 
a wide range of growing conditions. 
