135 



The Killing of Mustard and Other Noxious Weeds in the 

 Grain Fields of South Dakota. 



By E. W. Olive. 



To the best of the writer's remembrance, mustard, though abundant 

 euough, was not considered some years back as a serious pest in Indiana 

 grain fields. But throughout the great grain fields of the Northwest the 

 situation is different. The traveler sees on every hand, during the month 

 of June, field after field of grain absolutely yellow with the blossoms of the 

 common wild mustard. The fields sown to cereals are often enormous in 

 extent ; it is not an uncommou sight to see a quarter-section or even a 

 section sown to one crop of wheat, barley, oats or flax. Only small areas 

 here and there bear what we call "cultivated crops." Cultivation cannot 

 therefore hold in check troublesome weeds as is done in the smaller farms 

 of the older States. Hence the great abundance of the yellow pest through 

 the older parts of the Dakotas is actually startling to a stranger from In- 

 diana or Illinois. 



One large land-owner in an effort to rid his ranch of mustard, two 

 years ago spent a hundred dollars in pulling the weed. A year ago he 

 doubled his expenditures in this work ; but had to acknowledge finally 

 that it seemed as though no matter how careful and clean his methods of 

 farming, for years to come he might have to continually increase his ap- 

 propriation in geometrical ratio before he could ultimately hope to conquer 

 the pest. 



It may be of some interest to the members of the Academy to hear a 

 brief account of some of the experiments conducted by the writer during 

 the past summer in trying to eradicate mustard and other weeds in grain 

 fields. Similar experiments had already been performed in North Da- 

 kota, Canada, Minnesota, Wisconsin, and other western States, so that 

 the results obtained in South Dakota are in the main corroboratory. 



The method, in brief, is this : The grain field is carefully gone over 

 with a traction spraying machine, and sprayed thoroughly with a strong 

 solution (about 20 per cent.) of iron sulphate (or copperas). The ma- 

 chine used in our experiments covered a swath about twenty-five feet wide 

 and threw a very fine and powerful spray, under a pressure of from 80 



