lUill Disease Of Su^eet Corn 
PREVIOUS OCCURRENCES 
This disease is generally present south of the Mason and Dixon 
line and has greatly restricted sweet corn production there. During 
the periods of 1894 to ’97 and 1931 to ’33 wilt spread northward and 
caused serious losses to sweet corn growers in sections usually free 
from it. Each time these outbreaks were terminated by a severe 
winter. 
About 1928, Dr. G. M. Smith of the U. S. Bureau of Plant In¬ 
dustry, working at the Indiana Agr. Exp. Sta. developed a wilt resist¬ 
ant inbred strain of Golden Bantam, Later Dr. D. F. Jones and Dr. 
W. Ralph Singleton of the Conn. Agr. Exp. Sta. at New Haven, devel¬ 
oped wilt resistant inbreds of Whipple’s Yellow. Using these resist¬ 
ant inbreds, and others since developed, highly _ resistant hybrids 
are now produced that can make fine crops in spite of wilt. Much 
credit is due these scientists for thus solving the wilt problem. 
Last summer wilt advanced again into Southern New England, 
Hudson Valley, Southern Pennsylvania, Central Ohio, Indiana and 
Illinois. Many poor crops and failures of sweet corn that were 
blamed on seed, weather or something else, were really due to wilt 
disease. Losses may be more serious this season. 
NATURE OF THE DISEASE 
Wilt 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 vascular system and so cuts off the 
sap circulation and causes the plant to wilt. If infection occurs late 
enough a crop may be secured. 
Early infection usually is at the base of the plant. Wilting and 
withering progress upward till the stunted plant is dead. Later 
infections may start anyw’here at any stage. The wilting usually 
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 yellowish 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 bac¬ 
teria 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 winter over in the seed and in the bodies of certain 
insects, and they probably survive at least ono 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 favorable for the insects hasten spread 
of the disease. Mild winters like this one with shallow freezing of 
the soil, are followed by greater insect populations and more rapid 
spread of wilt. Severe winters seem to be the only natural check to 
the disease. No satisfactory control methods have yet been devised. 
SUSCEPTIBLE AND RESISTANT CORNS 
All the old varieties of early sweet corns, both white and yellow, 
are very susceptible, as are also early flint corns. Midseason var¬ 
ieties are less susceptible and late varieties, especially white, are least 
susceptible. Such fine varieties as Golden Gem, Golden Early Mar¬ 
ket, Whipple’s Early Yellow, Golden Sunshine, Golden Bantam and 
many other old favorites are so susceptible as to be worthless under 
severe wilt conditions. 
OUTLOOK FOR 1939 
It seems likely (not certain of course) that wilt will be a serious 
factor in sweet corn production this season as far north as Central 
New England, the Mohawk Valley, Lakes Ontario and Erie, Southern 
Michigan and Wisconsin and the southern boundaries of Minnesota 
and Dakota. It is likely to be worse at lower elevations and near lakes 
and streams and less severe at higher elevations. Some localities 
within the area probably would escape altogether. However, with 
plenty of seed of resistant hybrids available, it would seem just good 
business sense to use only such seeds in this area this year. 
RESISTANT HYBRIDS 
Not all hybrid sweet corns are wilt resistant. Many are not. 
Some of the better ones are listed below in the order of their earliness. 
Usually 9.5% - 98% Resistant 
Marcross C13.6 
Whip-Marcross C6.13 
Whipcross C6.2 
Whipcross P39 
Golden Cross Bantam 
LTsually 8.5% - 9.5% Resistant 
Spancross P39 
Ban-Whipcross R. C13 
Bancross P39 
Quaker Hill 0 K 
Quaker Hill X L 
Quaker Hill Hijbricls Rank HiqK 
Twenty or more experiment stations are testing new and old 
sweet corns. Their reports are available and worth studying. As 
might be expected, they show differences in yields of the same hybrids 
from different sources. Averaging results from ’37 trials, and ’38 
trials so far reported, where comparisons can be made, w^e find that 
Quaker Hill hybrids compare very favorably with those from other 
sources. For instance, our Golden Cross Bantam in these tests 
averaged 8% better yields than those from other sources. There are 
definite reasons for this but space does not permit explanation. It is 
enough that you know that hybrids from Quaker Hill Farm usually 
rank high in the experiment station trials. 
Other Qood Seeds 
At Quaker Hill Farm we produce also seed of the best-by-test 
strains of potatoes, Danish cabbage, oats, barley, field corn, wheat, 
rye and other field crops. From 500 to 1,000 acres of these crops 
are certified each year. We sell also hardy alfalfa, clover, grass, 
millet, and other forage crop seeds, all from approved sources. Be 
sure to see our general circular which describes these seeds concisely 
and accurately. It is instructive and the prices will interest you, too. 
A post card will bring you a copy. 
