19 



described by Johnson (loc. cit.) has been not uncommon, but we 

 could not see that it caused any appreciable injury beyond that 

 already done by the rust. 



Conclusions. 



The asparagus rust is caused by a parasitic fungus which was 

 named Piiccinia Asparagi by the elder de Candolle nearly a century 

 ago. 



The asparagus rust has occurred in Europe for some centuries but 

 the exact time that it was introduced into this country is unknown. 



The rust was first called attention to as occurring in the Eastern 

 United States by Prof. Halsted of New Jersey in the fall of 1896, 

 although there is a possibility of its having existed on Cape Cod one 

 or two years previous to this time. 



The severe outbreak of the asparagus rust is due to conditions of 

 the plants brought about largely by the excessive drought during the 

 seasons of 1895 and 1896, and in all probability the severity of the 

 attack was aggravated to some extent by the excessive rains of 1897. 



The rust as an injurious factor has been limited to only a few 

 places in Massachusetts, although especially affecting the asparagus 

 regions. 



The injurious effects of the rust have been confined to dry, sandy 

 soils possessing little capacity for holding water. Where the soil is 

 heavier, posscssii gmore water-retainingqualities, the rust has caused 

 no perceptib'e harm. 



The injurious effect of the rust is apparent only when tlie summer 

 stage occurs, viz., the red spores or uredospores which develop 

 during July and August. 



The fall stage of the rust, known as the black or teleuto, has been 

 prevalent all over Massachusetts since 1896, but this form has caused 

 no appreciable harm and is disappearing. 



The loss experienced from rust in Massachusetts this season, 

 caused by the severe uredoapore infection of 1897, was from 15 to 

 80 per cent in the yield of the marketable crop. The average loss 

 will equal 20 to 25 per cent. 



The practice of burning the affected tops in the summer has 

 resulted in injury, and no benefit has manifested itself from burning 

 in the fall. 



The results obtained by spraying asparagus are not encouraging. 



