CROWN-GALL AND HAIRY-ROOT DISEASES OF THE APPLE TREE. 17 



as shown b}'^ our experiments, develop into hairy-rooted trees with a 

 very deficient root systenL The hairy-root disease, as it appears from 

 the results of two 3'^ears' experiments, is not contagious. It is hoped 

 in the near future to be able to offer some practical means of reducing 

 the percentage of trees affected with these diseases in the nursery. 



DATA DESIRED. 



The hearty cooperation of nurserymen and orchardists in securing 

 data is desired. It is hoped to secure the help of the leading nursery- 

 men of this countr}^ in getting an accurate count from each nursery 

 of the number of diseased trees in at least one row of every variety 

 in all fields where the trees are all dug in one season. Such data are 

 desired from every locality wdiere apple trees are grown. Printed 

 blanks with directions for tabulating such data have been provided 

 and these will be sent to all who request them. Address the Missis- 

 sippi Valley Laboratory, St. Louis, Mo. 



