Lily Diseases 279 



the scales of the bulbs. The investigations by 

 Woods* have shown that the trouble is brought 

 about by a combination of causes. Poor cultural 

 conditions such as overwatering, or the use of poor, 

 unselected bulbs will generally and indirectly tend 

 to cause this disease. The bulbs may be further weak- 

 ened by the attacks of a mite {Rhizoglypkus echi- 

 nops) and of certain fungi and bacteria. The bulbs 

 may also become weakened by allowing the roots 

 to dry and then overwater. 



Control. The disease cannot be cured. The best 

 that can be done is to select strong, healthy bulbs. 

 Crop rotation to prevent the spread of the mite is 

 also recommended. 



Rust 



Lilies are subject to several rust diseases. The 

 most important is the American rust and is caused 

 by a species of Vromyces. This disease according to 

 Halsted t was first found on leaves of Lilium can- 

 didum at Buffalo, N. Y. 



The Botrytise Disease 



Caused by Botrytis sp. 



Symptoms. The trouble is apparent as small 

 rusty spots upon the buds, leaves, and blossoms. 



•Woods, A. F., U. S. Dept. of Agr. Div. of Veg. Phys. and 

 Path. Bui., 14: 7-15, 1897. 



t Halsted, B. D., New Jersey Agr. Expt. Sta., Fourteenth Annual 

 Kept: 392, 1893. 



