JtTLT 20, 1917] 



SCIENCE 



51 



cropping processes accounts chiefly foi' the 

 reduction of yields and the deteriorated 

 quality of the grain which comes from year 

 to year from the old, rather constantly and 

 extensively cropped cereal areas. I call 

 your attention to the history of wheat 

 cropping in California and in the semi-dry 

 regions of Washington and Oregon as af- 

 fected by smut epidemics. Ordinarily, in 

 the wetter regions, seed disinfection for the 

 prevention of stinking smut of wheat is all 

 that is necessary. It is not even necessary 

 to have a reasonable crop rotation, but in 

 semi-dry regions the smut spores do not 

 so readily die out by rapid germination; 

 and the combination harvesting and thresh- 

 ing has proved to be a process which 

 quickly undoes the work of possible con- 

 trol of smut through seed disinfection. 

 That process of cutting and threshing the 

 grain and returning the chaff, straw and 

 dust to the soil, evenly distributed, did 

 more than introduce smut. "With it goes 

 the spores of a large number of so-called 

 "imperfect fungi," particularly the Hel- 

 minthosporia and Fusarial types. These 

 and others have brought about seed and 

 root blighting, and with the smut, drought 

 and other conditions soon throws the crop 

 below a paying condition. 



In the hard spring wheat regions of Min- 

 nesota, North Dakota, South Dakota and 

 Montana, one readily sees the detrimental 

 influences of extensive cereal culture as 

 affecting the introduction, even distribu- 

 tion and destruction by the "imperfect 

 fungi" as transmitted by the seed to new 

 areas, by farming implements, wind and 

 wash waters, and as imbedded in the soil in 

 the dead bodies of the previous crop. 



It is a peculiarity of all these seed and 

 soil borne fungi that they are destructive 

 regardless of the year and soil conditions, 

 and vary in intensity according to weather 

 and soil conditions. Thus in intensely dry 

 seasons, particularly preceding the harvest 



time, old wheat lands often produce almost 

 normal, plump seeds, but when there is 

 sufficient water content in the soil and suffi- 

 cient rainfall during the heading period to 

 make a normal stand and growth for what 

 should be a large yield, these parasites resi- 

 dent in the seed and in the old stubble 

 lands and often evenly distributed during 

 moist weather from plant to plant, bring 

 about a rag-like condition of the cellular 

 tissues of the straw. They invade it at all 

 parts, and bring about an intense blighting 

 of the flowers and ovules at the time of seed 

 formation so that the heads are never 

 properly filled. Under these conditions 

 seldom any of the grains reach normal 

 form as to color, size and weight. 



To call your attention to what I have in 

 mind I can do no better than to quote from 

 some previous publications of mine in this 

 line. From Bulletin 13, North Dakota Ex- 

 periment Station, 1894, p. 26 : 



It is apparent that after all is said concerning 

 culture of wheat in the northwest, haphazard, 

 careless methods of saving the grains at harvest 

 time are yet to be placed as the chief cause in 

 the reduction of the milling quality of the wheat 

 as it now appears upon the market. 



From "Plans for Procuring Disease Re- 

 sistant Crops ' ' in Report of The Society for 

 the Promotion of Agricultural Science, 

 1907: 



At present the farmers are confused by conflict 

 of authority as to the proper Uae of seed improve- 

 ment. For the most part, they believe that seed 

 for crops must be bred to a high standard upon a 

 high-class soU and that it will degenerate when 

 put into general cropping conditions on their 

 farms. . . . The facts remain that crops suffer 

 under systems of constant cropping, while the idea 

 of home grown seed for local crops is fast gaining 

 recognition as right in principle. ... It is recog- 

 nized that crop diseases, as well as chemistry of 

 soil and air, play a great, if not master, role. . . . 

 Crop yields more often depend upon features of 

 disease resistance, or upon conditions of environ- 

 ment in which disease producing organisms can not 

 be active, than upon whether the soil is especially 

 balanced chemically. Crops fail as often through 



