WILT RESISTANT HYBRIDS YIELD 25% TO OVER 100% MORE 
Stewart's ID ill Disease 
The following statements are based on reports from 26 plant 
disease and vegetable crop experts at 18 different experiment sta¬ 
tions and from some 200 county agricultural agents and growers 
and canners in the Northeastern and North Central States. We 
thank them for their cooperation. 
Wilt was first studied and described by Dr. F. C. Stewart 
of the New York Geneva Agricultural Experimental Station in 
1804 to 1897. He found it on Long Island and in New Jersey 
where it was then doing considerable damage but later subsided. 
The disease has been for years quite generally prevalent in the 
Southern states and has practically eliminated from commercial 
production there all but late varieties of sweet corn, which re¬ 
sist or escape infection. Until recently, however, wilt has 
been absent from the northern tier states. In 1924 it began 
to spread northward and was reported in Ohio. It had spread 
over Illinois, Indiana, Ohio, Pennsylvania and New Jersey 
by 1931. In 1932 it moved into Southern New England, New 
York and Michigan and in 1933 was reported in all but the 
northernmost parts of these states. It is true that some sec¬ 
tions and many farms in this area have so far escaped but on the 
basis of spread in the last two seasons, all seem liable to infection 
this next season unless some natural agency checks the disease. 
This disease affects all sweet, pop, and field corns but is 
most destructive in early varieties, frequently causing complete 
loss of the crop. It is caused by a strain of bacteria which finds 
entrance to the plant by root, stalk, or leaves, fills up the vas¬ 
cular system and so cuts off the sap circulation and causes the 
plant to wilt. Infection may occur at any stage of growth, from 
seedling to maturity. If infection occurs late enough a crop may 
be secured. 
Early infections usually are at base of plant. Wilting and 
withering progress upward till the stunted plant is dead. Later 
infections may start anywhere at any stage. The wilting usual¬ 
ly spreads first in streaks along the leaves or stalks, then the 
streaks merge till the entire plant is dead, but sometimes the 
wilting diffuses quite rapidly. The wilted leaves are not yel¬ 
lowish but grayish brown. The spread from plant to plant may 
be slow or it may be so rapid that apparently healthy fields will 
succumb in a few days. The bacteria causing wilt may be 
squeezed out of the sap tubes of a freshly cut end of a diseased 
stalk. They appear as a sticky yellow substance. 
The bacteria are carried over in the seed and in the bodies of 
certain insects, and they probably survive at least one winter in 
the soil and in refuse. They are spread from plant to plant by 
corn rootworms, twelve spotted cucumber beetles, flea beetles, 
leaf hoppers, thrips, chinchbugs, and possibly by horses, men 
and machines moving along the rows. Weather conditions fa¬ 
vorable for the insects hasten spread of the disease. It is pos¬ 
sible that low winter temperatures and deep freezing of the 
ground may reduce insects sufficiently to lessen the spread of the 
disease in 1934. While this is to be hoped for it cannot be 
counted upon. 
Soil and weather conditions favorable for plant growth seem 
to favor wilt disease. 
Neither treating the seed nor dusting or spraying the plants 
has given satisfactory control. 
In general later planting of the same varieties seems to show 
less wilt than early planting, but there are exceptions. 
Different varieties vary in susceptibility. All early sweet 
corns both white and yellow" are highly susceptible and some early 
flint corns are susceptible. Midseason varieties are less sus¬ 
ceptible. Late sweet corns and dent field corns are least sus¬ 
ceptible. 
Certain inbred strains of sweet corn produced by artificial 
self fertilization for several years have proved to be highly re¬ 
sistant. This is particularly true of Purdue Bantam (1339) pro¬ 
duced by Dr. G. M. Smith of the U. S. D. A. at the Indiana Ex¬ 
periment Station and several other inbreds produced at other ex¬ 
periment stations but not yet released for commercial use. 
Hybrid seed produced with some of these resistant inbreds 
carries a high degree of resistance. As far as is known now, 
these resistant hybrids and late varieties offer the only reliable 
means of avoiding serious loss from Stewart’s wilt disease. Even 
if wilt disease should be eliminated by natural causes, the use 
of these more expensive hybrid seeds will prove very profitable 
because of the higher yields, equal or better quality, and greater 
uniformity as compared with open pollinated sweet corns. 
Hqbrid Svueet Corn 
One of the most interesting and successful plant breeding 
achievements of recent years is the production of hybrid sweet 
corns that actually yield 25% to over 100% more than the old fa¬ 
vorites, and that are amazingly uniform and of wonderful quality. 
The old method of improving sweet corn was to select early 
ripening ears of the desired type from healthy plants. Progress 
was very slow because the breeders knew the characters of only 
one of the parents. The pollen might have come from an infer¬ 
ior plant. The next step was to artificially cross two kinds of 
corn to get various recombinations of the characters of each. 
If something better resulted, then it was stabilized by selecting 
and close breeding. Golden Gem and Spanish Gold are results 
of this kind of breeding. The latest method of breeding is much 
better. 
HYBRID INBREDS 
Plant breeders have learned that by artificially inbreeding 
strains of corn for some years, then crossing -them by controlled 
pollination, they usually get in the first crop remarkable “hy¬ 
brid vigor” and also always the same definite and uniform char¬ 
acteristics. After producing hundreds of inbred strains and 
crossing them in thousands of different combinations, the breed¬ 
ers have succeeded in finding combinations of inbreds that pro¬ 
duce hybrids that are mighty near perfection. Golden Cross 
Bantam and Redgreen are examples. They are called hybrid 
inbreds. 
TOP CROSSED HYBRIDS 
Sometimes an inbred strain is so prepotent that when cross¬ 
ed on open pollinated strains, its characters dominate in the hy¬ 
brid. Such hybrids are called Top-Crosses. They may not 
equal hybrid inbreds but are much better than open-pollinated 
strains. Purdue Bantam (Inbred No. 1339) is used successfully 
in making Top-Crosses. Our Top-Crossed Sunshine and Top- 
Crossed Golden Bantam are examples. 
METHOD OF CROSSING 
The controlled crossing of two different corns is accomplished 
by planting -one row of the pollen parent to every two to four 
rows of the seed parent. Every plant in the seed rows is kept 
detasseled thruout the season so that their ears are fertilized by 
the pollen parent. These cross fertilized ears produce the hybrid 
seed. The two parent strains have to be maintained 
separately, and kept strictly self fertilized. Timeli¬ 
ness, thoroughness and everlasting watchfulness are 
absolutely essential. 
YIELDS 
The hybrid sweet corns we offer have yielded 25% 
to over 100% more than comparable open pollinated 
varieties. The following comparisons are from a few 
of numerous unbiased tests. 
Detasseling to Make Golden Cross Bantam 
U. S. D. A. Circ. 268. 
“In trials conducted for three years at LaFayette, 
Ind , this hybrid (Golden Cross Bantam) produced on the 
average, 3.84 tons of green corn per acre as com¬ 
pared with 2.49 tons of green corn per acre ob¬ 
tained from the highest yielding open-pollinated 
IF YOU PLANT WILT SUSCEPTIBLE CORN YOU RISK LOSS BY WILT 
