Diseases and Pests of the Apple and Their Control 223 



of the branch to elongate. The result is a whorl of leaves 

 at the tip and an absence of leaves along the side of the 

 limb, which lends to the branch somewhat the appearance 

 of a feather-duster. The exact cause of apple rosette is 

 unknown. Abnormal soil condition or insufficient nour- 

 ishment mav be responsible. In the Northwest the sow- 

 ing of alfalfa in affected orchards has seemed to exert a 

 beneficial effect. Good orchard practice, designed to pro- 

 mote normal growth of the trees, seems the principal cor- 

 rective measure. 



Baldwin-spot. 



This form of fruit-pitting is probably a physiological 

 disease due to abnormal plant growth. More and more 

 emphasis is being placed on good orchard management 

 as a correction to such physiological affections. The 

 maintenance of soil fertility and correct soil management 

 are of particular importance. In the Pacific Xorthwest, 

 regular irrigation with neither too much nor too little water 

 is essential in controlling such diseases. 



An internal browning has been more or less prevalent 

 in the Newtowns grown at Watsonville, California. Ex- 

 periments in controlling this latter disease have been con- 

 ducted for a number of years, but the disease is still puz- 

 zling to horticulturists. 



ANIMAL PESTS OF THE APPLE 



Meadow mice. 



The field or meadow mouse has become a menace in 

 many orchard regions, particularly in the South where the 

 sod-mulch provides harbor. The mice attack the trees by 



