'270 FIELD CROPS FOR THE COTTON-BELT 



ticularly those with hard grains. The selection of seed 

 with the idea of gettipg a husk that fits tightly over 

 the end of the ear has been found to decrease weevil 

 inji^y. 



The most effective means of fighting the grain weevils 

 or moths is that of fumigating the stored grain with the 

 vapors of carbon-disulfide (CS,), which is a very volatile, 

 colorless liquid. In order that this method may be used^ 

 successfully, the grain must be stored in a bin or crib 

 having unusually tight floors, walls, and roof so that the 

 vapors will be confined until they have thoroughly pen- 

 etrated the entire mass of grain. Hinds ^ states that "it 

 requires at least forty-five minutes' exposure to a very 

 strong gas to kill the black weevil adults and the smaller 

 brown beetles are still more resistant." The amount of 

 carbon-disulfide to use to a 1000 cubic feet of volume to be 

 fumigated is from ten to twelve pounds for a very tight 

 crib to twenty-five pounds for one that is moderately tight. 

 The liquid may be placed in shallow pans on top of the 

 corn or it may be poured in small holes about the surface 

 made by pullitig out a few ears. It evaporates very rapidly 

 and the vapors being heavier than air diffuse downward 

 through the grain. The treatment will not injure the 

 grain either for food or seed. Immediately after the treat- 

 ment the crib should be tightly closed. The vapors of 

 carbon-disulfide, when mixed with air form a gas that is 

 easily exploded if brought in contact with fire. All lighted 

 cigars, cigarettes, lanterns, and the like, must be kept away 

 while the fumigating is being done. 



FUNGOUS DISEASES 



Corn is remarkably free from fungous diseases. The 

 1 Ala. Agr. Exp. Sta., Bui. 176, p. 65. 



