FIELD DISEASES 141 



of moisture in the atmosphere. The 

 acervuli or spore pustules appear within 

 five days after wilting begins, unless the 

 weather is dry, when they may not appear 

 until considerably later. 



MOSAIC DISEASE OF THE SWEET PEA 



Sweet Pea Mosaic is a serious disease. 

 It greatly checks greenhouse peas and is 

 equally injurious to sweet peas grown out- 

 of-doors. Although the cause of the 

 trouble is not as yet known, nevertheless 

 all indications tend to show that it is in- 

 duced by a definite pathogenic organism. 

 The same or a similar mosaic is known to 

 attack a number of plants such as tobacco, 

 egg plant, pepper, tomatoes, and clovers. 

 Its occurrence on the sweet pea has been re- 

 corded only by the author * though it has 



^ Taubenhaus, J. J., Present knowledge of sweet pea 

 diseases. Florist Exchange 34: 108-110, 1912. 



