PAPERS ON BIOLOGY AND AGRICULTURE 247 



The rather warm winter of 1921-22 allowed certain ol 

 the rusts to overwinter and probably was helpful in pro- 

 viding an unusual amount of viable infectious material. 

 Frequent showers with excessive precipitation during 

 early spirng was productive of certain early fruit di- 

 sease infections and of rust epidemics. On late maturing 

 crops, and on crops not planted until the wet period had 

 passed, these diseases were held in check by the subse- 

 quent dry and hot weather. 



CEREALS 



Barley: Loose smut (Ustilago nuda (Jens.) K. & S.) 

 was about the same in severity as in the average year. 

 Our estimates indicate 0.2 per cent of the plants of the 

 state affected, with a crop, loss probably not large enough 

 to be estimated. 



Stem rust (Puccinia graminis Pers.) was generally 

 prevalent in small amounts, and resulted in only very 

 slight losses. 



Corn: Bacterial wilt (Psendomonas stewarti E. F. S.) 

 was locally important, but was not an important factor 

 in reducing the yield of the state. 



Brown spot (Physoderma zeae-maydis Shaw) was less 

 severe than usual. Reports and specimens collected 

 through the state indicate that it has extended its range 

 northward to Lee county. 



Rosen's disease (Pseudomonas dissolvens Rosen), 

 hitherto noted in two counties, made its appearance in 

 Union County. Here a field of 10 acres showed 1 per 

 cent of the stalks diseased. The characteristic twisting 

 at the base of the stalk was present throughout the in- 

 fected area. Later examination of material from the 

 infected field by Dr. Rosen positively identified the di- 

 sease. 



Rust (Puccinia sorghi Schw.) appeared later, and was 

 less abundant in the state, than usual. Undoubtedly, the 

 dry hot weather during the usual infection period served 

 to minimize the infection. 



Smut (Ustilago zeae (Beckm.) Ung.) was apparent in 

 about the same amount as during average years. A re- 

 duction in yield for the entire state of 2.5 per cent is 

 estimated. 



