540 



SCIENCE 



[N. S. Vol. XXXII. No. 825 



spores present for which disinfection was 

 originally brought out. In North Dakota 

 I have found that on the basis of a twenty 

 bushel yield, number one hard seed, free 

 from smut, disinfected with formaldehyde, 

 may be expected to give, when planted on 

 the same soil on the same day, from one 

 and a half to four bushels per acre more 

 than the same wheat not disinfected. For 

 years I could not explain this any more 

 than to say, "It is possible that formalde- 

 hyde may act as a stimulant to the young 

 plant, or that it is possible that it may de- 

 stroy other fungi such as bacteria, yeasts 

 and moulds, etc. I now know that the 

 spores of these soil and root diseases may 

 often be present on the exterior of such 

 seed, and thus we have a clear explanation 

 and reason why all seed should be disin- 

 fected every year, regardless of the pres- 

 ence or absence of smut. 



As previously indicated, the idea of con- 

 serving the fertility of the soil seems to be 

 as old as agriculture, but the study of the 

 soils from the standpoint of the health of 

 the cropping plant as viewed from physical 

 and mechanical texture and its disease- 

 bearing features, are matters which have 

 had much too slight attention. Overlook- 

 ing them, we have not been able to explain 

 the conflicting results obtained by our best 

 theories or methods of cropping. We have 

 had our thoughts centered on the possible 

 loss or depletion of fertility and upon the 

 possible unbalancing of the food ratio as 

 represented in eleven to fourteen chemical 

 elements, and although we have known 

 well that a plant can use up essentially 

 every bit of an available plant food before 

 deterioration becomes apparent in its 

 growth qualities, we have blindly assumed 

 that many soils which from their texture 

 and age should be thoroughly fertile, are 

 nevertheless depleted in their food supply. 

 We have paid too little attention to the 



life of the plant itself and to biological 

 features connected therewith, and to the 

 needs of adapting our cultivation methods 

 to the actual physiological processes of the 

 plant that it may not sicken and become so 

 weak as to fall an easy prey to its enemies. 



Just at this point, I may say that these 

 root diseases are of such nature, whether 

 we speak of flax or wheat, that certain va- 

 rieties and strains of the crops may be 

 recognized as markedly resistant, and that 

 even the common crop may resist to such 

 extent as to produce a reasonable yield on 

 a normal year. Yet through any untoward 

 condition, such as the bites of insects, or 

 injuries due to dry air coming in contact 

 with the roots in a loosely prepared seed 

 bed, or due to the weakening effects of 

 poor drainage, the individual plants and 

 the average of the crop may fall a ready 

 prey to the disease-producing organisms. 

 These organisms are not only parasites in 

 their ability to attack young growing 

 plants, but they are rather more sapro- 

 phytes than parasites in the sense that 

 whenever a plant tends to sicken and die 

 they readily attack and overcome it, so 

 that poor drainage and drought, heat, 

 frost and insect depredations, greatly facil- 

 itate the destruction occasioned. 



It is my belief that these soil and seed 

 diseases, especiallj' of wheat, flax and oats, 

 have broken many a hope for a large crop, 

 and have vitiated the conclusions drawn 

 from nfany well-planned schemes of crop- 

 ping. 



What has this to do with the dry land 

 farming? As previously indicated, there 

 are great areas of this country that have 

 been contaminated with cereal diseases. 

 The methods of constant cropping, care- 

 less selection of seed, lack of seed disinfec- 

 tion, and the lack of proper preparation of 

 the seed bed so as to properly firm it down 

 and thus insure that the fine roots shall 



