B. P. I. 349. 



SOME STEM TUMORS OR KNOTS ON APPLE 

 AND QUINCE TREES." 



OCCURE-ENCE OF TUMORS. 



A peculiar form of tumors or knots has been observed by the writer 

 during the past five years occurring on the trunks, limbs, and twigs 

 of apple trees (fig. 1) and quince trees (fig. 2) in a number of local- 

 ities in various portions of the United States. These localities are in 

 some cases widely separated, indicating that the disease may be found 

 occurring over a wide extent of territory. The tumors on the quince 

 have been observed at Chico and other points in California, and re- 

 ports of their occurrence, with specimens, have been received by the 

 writer from Ansted, W. Ya. Those on the apple have been noted in 

 a number of localities in California, Oregon, New Mexico, Texas, 

 Arkansas, Kansas, Nebraska, Iowa, Missouri, Illinois, and West 

 Virginia. Specimens taken from apple seedling trees have been 

 received from Mr. C. G. Woodbury, of the Indiana Agricultural 

 Experiment Station, collected in southern Indiana. 



Garcia, of the New Mexico Experiment Station, reports the disease 

 on apple trees from Mesilla Park, Hatch, and Garfield, N. Mex. 

 Garman,^ of the Kentucky Experiment Station, has described a form 



« Tliis paper records the results of observations and experiments on a type 

 of disease that occurs in the apple and quince orchards and is particularly 

 troublesome to nurserymen. The tumors described are related to hairy-root 

 and crown-gall, and this publication summarizes a part of an extensive inves- 

 tigation which Doctor Hedgcock is pursuing on the crown-gall and related dis- 

 eases. The paper brings out some important facts regarding the relation of 

 the knots above ground to certain forms of hairy-root, and contains advice to 

 nurserj^men as to how to avoid the trouble. These investigations were begun 

 at the Mississippi Valley Laboratory, St. Louis, Mo., under the direction of Doc- 

 tor Hermann von Schrenk, and will be continued under the direction of Mr. M. B. 

 Waite, Pathologist in Charge of Investigations of Diseases of Fruits. — B. T. 

 Galloway, Pathologist and Physiologist, and Chief of Bureau. 



^ Garman, H. Diseases of Nursery Stock— A Knot Disease of Apple Trees. 

 Kentucky Agricultural Experiment Station, Bulletin 93, pp. 106-107 ;ind fig. 4, 

 1901. 



[Cu-. 3] 



5 



