SEVENTEENTH ANNUAL YEAR BOOK— PART X 575 



Corn rust (Puccinia sorghi). This rust, though common on leaves of 

 corn, injured the corn somewhat. The uredo stage occurs toward the 

 latter part oif July and early August. The aecidium stage was not 

 observed. The disease is widespread in Iowa and is more injurious to 

 sweet corn than field corn. 



Clover rust {Uromyces Trifolii) was not common and only occurred 

 on second crop clover late in the season. 



Alfalfa rust (Uromuces Trifolii) was not common. 



Asparagus rust (Puccinia asparagi) was widely distributed, though 

 not as common as the year previous. 



Apple rust {Gymnosporangium macroinis) , though widely distributed, 

 was not severe as the. previous season because the infection period for 

 the red cedar was shortened. 



Two important rusts must be reported this year: the hollyhock rust 

 (Puccinia malvacearumj , reported for the first time by a correspondent 

 in Tama co'unty. The writer has looked for it for some years in Iowa, 

 but without finding it. It is said to occur in "Wisconsin. 



Snap dragon rust was reported from Scott county. 



Another rust (Uredo ,Campau1ae) was reported from Bagley also 

 for the first time. 



Timothy rust (Puccinia Phlei-pratensis) was not common. 



Wiheat blight (FuS[arluni cuhnorum) was not common. 



Sorghum blight (Bacillus Sorghi) was fairly common. 



Oats smut (Ustilage avenue and U. laevis). These smuts were fairly 

 abundant and damaged the oat crop to a considerable extent. The loss 

 to the crop has been estimated at $6,300,000. Farmers do not distinguish 

 between the two species. The loose smut (V. avenae) was somewhat 

 more abundant than the covered smut (U. laevis). Loose Smut of ^¥heat 

 was common and injurious. 



Bunt {Tilletia foetens) was not common; found only in Davis County. 

 It probably occurred in other wheat sections of Iowa. 



Rye smut {Urocystis occulta). Rye is not grown extensively in Iowa. 

 Chiefly in the sandy region of eastern Iowa. This smut was not un- 

 common in Davis County. 



Corn smut {Ustilago zeae) found everywhere in Iowa. The amount 

 of injury to the crop varies in different localities. The damage to the 

 crop varies greatly. In some fields as much as 10 to 15 per cent of the 

 corn stalks show corn smut. On such stalks the ears are generally 

 smaller and in some cases the stalks are barren. Only about 1 per cent 

 of the ears show corn smut. 



The two barley smuts, the naked {Ustilage nuda) did an estimated 

 damage of 3 per cent, and the covered smut (C7. Jiordei) 2 per cent. Few 

 of the farmers cf th6 state treated their seed. This is in strong contrast 

 to the custom cf the onion growers oif Scott County who treat their seed 

 regularly witli formalin by the drip method so that little of the onion 

 smut (Urocystis cepulae) was reported. 



Smut on poppy (Entyloma papaveris) . A number of years ago, about 

 1910, the writer observ^.d in a flower garden in La Crosse, "Wisconsin, an 



