890 



SCIENCE 



[N. S. Vol. XXXI. No. 806 



the work of men of little or no botanical 

 training. 



With the establishment of the numerous 

 agricultural experiment stations in all 

 parts of the world, the doors were opened 

 wide to scientific men to work for the ad- 

 vancement of agriculture. It is instruct- 

 ive to review the general trend of what 

 took place in the fields of agronomy and 

 horticulture, which, broadly speaking, not 

 only cover the whole subject of crop 

 plants, but soils as well. Generally speak- 

 ing, there are four potent and more or 

 less controllable factors which affect the 

 yield of crops. These are tillage, fertiliz- 

 ers, rotations and variety of plant. To 

 these might be added the prevention of 

 loss by diseases or insects. Broadly 

 speaking, three types of scientific men 

 went into agronomic work. First, those 

 who were interested in the study of fer- 

 tility. For the most part, these men were 

 and are chemists and they have studied 

 their problem largely or wholly from a 

 chemical standpoint. Probably as a re- 

 sult of their chemical training the field 

 plot work of these investigators is by far 

 the most accurate agronomic field work 

 conducted. The theoretical side of the 

 subject of soil fertility has recently been 

 stimulated by vigorous attacks on the 

 long-accepted theory of available plant 

 food — an explanation so luminously 

 simple that a few pages of text sufficed to 

 tell the whole story. It may devoutly be 

 hoped that a renewed activity in the study 

 of fertility may stimulate botanical work 

 on the nutrition side of the problem — 

 which is pretty nearly where Sachs left it 

 forty years ago. The second class of sci- 

 entific men who were attracted to agro- 

 nomic work were botanists. In large 

 measure, these men undertook investiga- 

 tions dealing with plant diseases, with the 

 end in view of preventing or curtailing 



the serious losses resulting from such 

 causes. The results of their work fur- 

 nish the best contributions that botany 

 has thus far conferred on agriculture in 

 this country. So far as field crops are 

 concerned, there are decided limitations 

 to the use of any direct preventive meth- 

 ods such as spraying. As a natural re- 

 sult, investigators of the diseases of such 

 plants were forced to adopt one of two 

 lines of approach to the solution of the 

 problems involved. They could either 

 seek for immune or resistant varieties or 

 they could make a comprehensive study 

 of the crop and the disease and endeavor 

 by such indirect methods as rotations to 

 curtail the disease loss. In either case the 

 result was that the pristine pathologist 

 often graduated into an agronomist. The 

 third class of men who went into crop in- 

 vestigations were generally termed agri- 

 culturists and horticulturists. • They 

 constituted by far the most diverse 

 group. In a few cases they were simply 

 good farmers. In some cases they were 

 men of very broad training. For the 

 most part they were men with good 

 general equipment. To these men fell 

 the great bulk of the field work involv- 

 ing principally investigations into tillage, 

 rotations and the testing of crop varie- 

 ties. It thus fell largely to this third 

 class to investigate the complex problems 

 of plant varieties. Even in the few cases 

 where experiment-station agriculturists 

 and horticulturists had good botanical 

 training, the diverse problems facing 

 them as well as paucity of literature gave 

 little opportunity for far-reaching studies. 

 Generally speaking, one of two plans was 

 pursued. In the one case a series of va- 

 rieties was grown, and all but a few of the 

 apparently most promising were dis- 

 carded without further ado. In the other 

 case more or less full information was 



