
Ts CHINA ASTER is one of the loveliest flowers to be found in any garden, and it has been developed 
and cherished for hundreds of years as the most colorful of the late summer annuals. Provided ihat 
one may be assured of healthy plants, few flowers can challenge its popularity. Twenty years ago 
however, Aster Wilt, one of the primary Aster diseases, became so widespread as to threaten ihe very 
existence of the Aster family itself, and nullify the patient work that produced the many beautiful varieties 
seen today. How this disease was mastered, and how the Aster was returned to its preeminent place in 
home and commercial growing makes a fascinating story: 
To begin with: Wilt is caused by the fungus Fusarium conglutinans var. Callistephi, which lives in the 
soil. It may be spread by tools, water, Aster seed—anything that comes in contact with a diseased plant, 
and it persists almost indefinitely. It may be avoided if the grower plants land which has never grown 
Asters before, but this course is usually impractical. There is at present no known drug or chemical which 
will destroy the fungus. How, then, is Aster wilt conquered? 
The process developed by Bodger Seeds Ltd. in the pioneer work which established the firm as the 
largest successful growers of Aster seed in the world is relatively simple: Much like vaccination among 
human beings, it consists of exposing test plants to a case of Aster wilt. The plants which develop anti- 
toxins, or resistance, survive, and supply seed for the next generation of test plants. The number of wilted 
plants is of little importance provided ihat strong wilt resistance is obtained, and so the test plants get 
an extremely heavy dose of fungus in the Pest House, a twenty-acre farm in charge of Bodger experts, 
devoted solely to wilt research work, and expressly infected with as much wilt as possible. 
The tendency to wilt-resistance can be inherited, and the Aster plants grown from the seed produced 
the previous year are quite resistant—but the process does not stop there. These descendants of the first 
test plants are again grown in the Pest House, so that only those lines which have a strong tendency 
to wilt-resistance may survive to give seed for bulk plantings. By means of this technique—the survival 
of the fittest—Bodger’s original strains of wilt-resistant Asters were developed. 
It must be borne in mind that in all cases it is resistance, not immunity, which is developed. The 
tendency toward resistance is an inherited characteristic which will ‘‘breed out’ in several generations 
if the plants are not ‘‘vaccinated,’’ or put through the Pest House cycle again within a reasonable time. 
Again, the Fusarium is quite unstable, mutating to produce fungus which will overcome the resistance 
