•FIELD WOKK IN PLANT PxVTHOLOGY. 109 



conditions is just as necessary for this work as it is in the deter- 

 mination of the best methods of treatment. The plant patholo- 

 gist should have at his disposal specimens of various kinds of 

 cultivated plants, or should certainly have the opportunity to 

 grow them as the needs present themselves, not alone in the 

 greenhouse, but also in the field. While much can be done in 

 the laboratory upon the etiology of diseases, the work must be 

 carried further in our i)lant houses and finally taken to the field. 



Inoculations with disease-producing organisms, either in 

 pure cultures or as direct transfers from affected hosts, can in 

 many cases be made equally well in field or greenhouse, but with 

 many of the large perennial plants it is nearly always necessary 

 to go to the field. For example, inoculations of wood-destroy- 

 ing fungi may be made into liealthy trees and the trees marked, 

 and visited at a later time to determine the result. Tt might be 

 necessary to wait years for results in some cases, while others 

 would give much quicker returns. 



I have passed in brief review some of the features of field 

 work in ]dant pathology, and now I wish to call your attention 

 to the plan which has already been inaugiirated in several states 

 to have one or more field men spend their time during six 

 months of the growing season investigating pathological prob- 

 lems in the field, or demonstrating the effectiveness of known 

 preventive measures. The value of work of this sort has al- 

 ready been demonstrated in several states, and it only remains 

 for the wisdom of our legislators to extend the work. In so 

 doing they will foster the development of an interesting and 

 important phase of botany, and will benefit the agricultural in- 

 terests to such an extent that the expense of the work is a mere 

 pittance in comparison. 



Agricultural Experiment Station, Lincoln, I^eb. 



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