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JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 17 
its host plants, and the difficulty of detecting all affected plants, official inspection of 
nursery stock for the purpose of preventing the dissemination of the crown-gall 
organism is unwarranted. The sole object of crown-gall inspection is to prevent 
the sale and planting of stock which will not produce a normal crop. If it be as¬ 
sumed that all plants affected by crown-gall are unfit for planting no method of official 
inspection is adequate protection for the planter, because of the nature and wide 
distribution of the causal agent. Inspection regulations should be framed with these 
things in mind and a clear distinction should be made between crown-gall and mal¬ 
formations due to excessive callousing, cultivation injury, woolly aphis, and nematode 
injury. 
2. The amount of injury done by crown-gall varies greatly with different species 
of plants and, in some cases, even with different varieties of the same species. Also, 
it appears to vary somewhat with the character of the soil, methods of culture, and 
climatic conditions. Accordingly, it is impracticable to have uniform inspection 
regulations for ali kinds of plants or for all parts of the United States. 
3. In each State the extent of the injury done by crown-gall to the principal 
economic plants grown in the State should be accurately determined and the findings 
used as the basis of inspection regulations. Generally speaking, the persons best 
qualified to do this are the plant pathologists and horticulturists of the Agricultural 
College and the Agricultural Experiment Station. They should be consulted freely 
by those in charge of nursery inspection. 
4. In general, the injurious effects of crown-gall have been over-estimated, 
particularly in the case of the apple. Crown-gall injury is least pronounced in the 
northern and north-eastern portions of the United States. 
5. Crown-gall inspection regulations should describe fully, and as accurately as 
may be possible, the symptoms shown by plants to be rejected. To say that “all 
plants visibly affected by crown-gall will be rejected” is not sufficiently explicit. 
Hair-splitting methods of inspection are unnecessary and should not be permitted. 
Considerable tolerance should be allowed. 
6 . Field insptetion for crown-gall is unreliable. The only worth-while inspection 
is that made at the packing shed or at the point of destination. 
7. Except as a penalty for law violation, the rejection of an entire shipment 
because some plants in it are affected by crown-gall is unwarranted. 
8 . In view of the foregoing it is recommended that this Society solicit the active 
cooperation of the American Association of Nurserymen in a research program that 
will ultimately answer the questions now involved, directly and indirectly, in a better 
understanding of the nursery inspection problems relating to crown-gall. 
Respectfully submitted, 
F. C. Stewart 
M. J. Dorsey 
J. E. Mehhus 
Harry F. Dietz 
Henry B. Chase 
Committee 
Voted that the report be accepted and that the committee be contin¬ 
ued with its present personnel so far as this association is concerned. 
At the close of the discussion of the symposium on “Methods of 
