SHUCK PROTECTION FOR EAR CORN. 9 
The ears examined were of three classes. The first class had shucks 
extending from 4 to 6 inches and the second class from 2 to 3 inches 
beyond the tips of the ears; the third class had practically no shucks 
extending beyond the tips of the ears. The relation of shuck cover- 
ing to infestation as it was found in these classes is shown in Table V. 
TaBLE V.—Relation of the shuck covering of corn to insect infestation in 1916. 
Percentage of ears— 
Number 
P oh ater of ears | Affected 
Kind of shuck covering. exam- |Attacked| Infested Sate 
ined. by with ah 
worms. | weevils. aL 
Extending 4 to 6 inches beyond tips of ears..............------- 111 72 9 64 
Extending 2 to 3 inches beyond tips of ears.....-....--.-.-..--- 102 87 22 77 
IPrachicallysnoextensione eee oa cise i see meses oe ae 100 96 100 91 
Of the 111 ears with shucks extending from 4 to 6 inches beyond 
the tips of the ears, 72 per cent had been attacked by worms, 9 per 
cent had been infested by weevils, and 64 per cent had been affected 
with worm mold. Of the 102 ears with shucks extending from 2 to 3 
inches beyond the tips of the ears, 87 per cent had been attacked by 
worms, 22 per cent had been infested with weevils, and 77 per cent 
had been affected with worm mold. Of the 100 ears with practically 
no shuck extension beyond the tips of the ears, 96 per cent had been 
attacked by worms, 100 per cent had been infested by weevils, and 
91 per cent had been affected with worm mold. 
In the case of worms, 15 per cent fewer ears were attacked in the 
4 to 6 inch extension shucks than in those having 2 to 3 inch exten- 
sions, and 24 per cent fewer than where there was practically no exten- 
sion. There were 13 per cent fewer ears infested with weevils in the 
4 to 6 inch than in the 2 to 3 inch extension shucks and 91 per cent 
fewer than in the shucks having practically no extension, while 13 per 
cent fewer ears were affected with worm mold in the 4 to 6 inch ex- 
tension shucks than in the 2 to 3 inch extension shucks, and 27 per 
cent fewer than in those having practically no extension. 
These figures make it clear that length of shuck extension is a 
controlling factor in the matter of ear damage. In addition, the 
relationship between the length of shuck extension and the percentage 
of ears attacked by worms is of special interest because, in connection 
with the following evidence, it suggests a possible means of over- 
coming the most serious obstacle in the way of making a perfectly 
effective shuck protection for practically all of the ears. 
SHUCK EXTENSION AS A PREVENTIVE OF WORM DAMAGE. 
The foregoing discussion has made it clear that earworms may be 
responsible (directly and indirectly) for much damage to corn. The 
Q 
fact that earworms can and sometimes do cut holes through a 
