12 DISEASES OF ECONOMIC PLANTS 



188S Organization of the State Agricultural Experiment Stations. 

 1890 The beginning of pump improvement for spraying. 

 1906 The passage of the Adams Act. 



DAMAGE CAUSED BY PLANT DISEASES 



The crop grower, in his ignorance of what plant diseases 

 are, often suffers much damage from them, entirely uncon- 

 scious of the fact that his crop is affected by disease. Or, 

 if the presence of disease is recognized, the amount of 

 damage is often underestimated. Thus oat smut to the 

 extent of 15 or even 40 per cent is sometimes entirely over- 

 looked by an otherwise observant man. 



An attitude of willful disbelief in the prevalence of a 

 disease is often couched in such terms as these : '' I don't 

 see why I must work to protect my apples from rot. My 

 grandfather used to raise fine apples without any attention 

 to these things." 



It must be recognized that plant diseases are with us ; 

 that they are increasing by importation from other coun- 

 tries or other states ; that diseases formerly insignificant 

 are, in many instances, becoming serious ; that long, inten- 

 sive culture of one crop in a locality permits new diseases 

 to develop. Diseases have many means of dispersal : on 

 seed, hay, or other produce shipped by mail, express, or 

 freight ; on animals ; by wind ; by water ; by birds. Dis- 

 eases will continue to spread and to increase in destructive- 

 ness until the individual and the general public are aroused 

 to such active appreciation that conditions of plant sani- 

 tation and plant protection become much more general 

 and~ effective than they now are. 



