2 BULLETIX 108, U. S. DEPARTMENT OF AGRICULTURE. 



is being taken in the matter to bring about practical results. This 

 is especially true in view of the fact that very little experimental 

 work has been done to determine the relationship that really 

 exists between shucks and the corn inclosed by them. However, 

 some reassuring observations in this connection have been recorded 

 by W. E. Hinds, entomologist of the Alabama Argicultural Experi- 

 ment Station.^ Below are given certain significant quotations: 



The earliest maturing corn — almost regardless of variety — attracts them [weevils] 

 in greatest number and naturally the ears that have exposed tips and loose, open 

 husks are then the first and most heavily attacked. * * * But naturally the com 

 from the outer edges of the field and the poorly covered ears throughout the field 

 will always contain more weevils than any other equal number of ears. * * * 

 The two most important factors in producing this [weevil infestation] variation [of 

 varieties] are generally comparative rapidity of development to maturity of the grain 

 and the relative length and tightness of the husk covering. * * * From our 

 study of these varieties, we have become convinced that weevil resistance depends 

 first of all upon the length and tightness of the husk covering upon the maturing ear. 

 * * * Long husks can be bred by selection in any variety. * * * Good husk 

 covering and proper storage methods may entirely prevent the necessity for fumigation 

 treatment. 



In the following pages are given the results of investigations whqge 

 object has been to establish definitely by positive means some of the 

 more important facts regarding the merits of shucks as a means of 

 preventing ear damage. 



RELATION OF SHUCK CHARACTERS TO INSECT INFESTATION. 



FIELD INVESTIGATIONS. 



The field investigations described in this bulletin were conducted 

 during the period from September 27 to October 4, 1915. The 

 experimental corn had been planted on IMarch 22 and 23 at Thomas- 

 ville, Ga., and was among the first planted in the community that 

 year. At the time the data were collected the moisture in the grain 

 varied with the variety from 12.5 to 15 per cent. 



Fourteen native southern varieties were included in the investiga- 

 tions. They were grown in adjacent rows and harvested and studied 

 separately, but for the purposes of this bulletin the results are con- 

 sidered collectively. 



The ears were harvested with all of the shucks in place. They 

 were then separated into three classes, termed "poor shucks," 

 "good shucks without wormholes," and "good shucks with worm- 

 holes." 



Ears were classified as having poor shucks if the shucks failed to 

 extend beyond the tip of the ear or if extending beyond the tip 

 they did not close tightly and seemed to offer opportunity for insects 

 to enter along the passage used by the silks. 



1 Rinds, W. E. Reducing bisect injury to seed corn. Ala. Agr. Exp. Sta. Bui. 176, p. 49-6S, 4 pi. 1914. 



