148 



troatiueiit. In an cxi)orimontal plot in Dekalb county, nntreatod seed 

 yielded tubers showing 87% infection of black scurf as compared with 

 41% from treated seed. In a similar test in Lake county, there was G9% 

 black scurf where untreated seed was used as compared with to 13% 

 where treated seed was used. 



Russet scab was found in Lake County. Its cause is not well under- 

 stood. Silver scurf caused by SpondylochidiKm ntroinrens was found on 

 seed stock in Dekalb County. Leak caused by Pythium was found at 

 Lafayette in freshly dug tubers kept in a warm place. 



A rather careful search of the state for the black wart disease accom- 

 panied by educative propaganda to enlist tlie assistance of the growers and 

 consumers in tlie search was made in cooperation with the federal plant 

 disease survey by J. H. Weghorst. None of the disease was found. 



Radish. 



P>lack-root attributed to Rhcosporanffinm aithauidcrmalus was the most 

 serious disease of radishes and was an important loss-producing factor 

 in the culture of the white varieties especially in heavy clay soils. Not 

 only are the blackened lesions objectionable in themselves, but are gen- 

 erally invaded by rot-producing organisms. 



White rust caused by Cj/stopus cauilidus was prevalent in certain green- 

 houses. A rot of the leaf bases due to Sclcrotiiiia lihcrfidna was also 

 noted in greenhouses. 



Raspberry. 



Orange rust due to (lynniorniiid pcrkiaiia was of widespread occurrence 

 early in the summer. 



Anthracnose caused by (llocosporiiim rrncluni was very severe this year 

 and was the worst disease of black raspberry in Indiana. It was especially 

 important in Fountain County. In a plantation near Silverwood this dis- 

 ease lias been so severe that it lias led to a metliod of culture in which 

 the vines are forced until two or three good crops are secured after 

 which they are destroyed and replaced. 



The non-parasitic yellows disease occurred locally. 



RlIURARI!. 



Leaf-spot caused by A.scocln/fd rJici was of general occurrence. 



Rose. 



Powdery mildew ( Spliarrofhccd pdinio.sd) was vei+/ destructive in 

 greenhouses. I'specially on the Killarney varit'ty. It was also prevalent on 

 the Ramblers in June. 



Black spot caused by Actiiioiicnid rostir was found in the greenhouse crop 

 and was most serious on the Russell variety. 



Rye. 



Twenty-eight fields in 17 counties were examined in the course of the 

 federal cereal disease survey. Seiitoria on the heads was reported from 



