208 Proceedings of Indiana Academy of Science 



leaf-roll and supplies another potent reason for using northern-grown 

 certified seed stocks. Mosaic may be more readily detected in the 

 field than leaf-roll. 



Black-leg, caused by Bacillus phytophthorus, was noted in the early 

 crop. Early blight, caused by Alternaria solani, occurred rather gen- 

 erally late in the season. Tuber blemishes due to scab (Actinomyces 

 scabies) and black scurf (Rhizoctonia solani) were generally prevalent 

 where seed disinfection was omitted or soil infestation existed. The 

 hot weather made scab worse. Silver scurf, caused by Spondylocladium 

 atrovirens, was found causing a shrivelling of potatoes of the 1921 crop 

 in storage. 



Quince. — Fruit lesions of Fabraea maculata were found in Miami 

 County as well as an Alternaria rot of the fruit. 



Radish. — Black-root, caused by Nematosporungitun (Rheosporang- 

 ium) aphanidermatum, occurred very generally near Lafayette early 

 in the spring. 



Raspberry. — Anthracnose, caused by Plectodiscella veneta, is the 

 limiting factor in the black cap industry and by its girdling effect near 

 the ground line kills the canes just before the fruit is matured. Leaf 

 spot, caused by Mycosphaerella rubi, occurred very generally. Ci'own 

 gall was noted in a few localities. 



Rhubarb. — Leaf-spot, caused by Ascochyta rhei, was prevalent as 

 usual. 



Rye. — Anthracnose, caused by Colletoiriclumi cerealc, stem rust, 

 stem smut (L'rocystis occulta), powdery mildew (Erysijihe g)-aiiii}iis) , 

 and ergot (Claviceps purpurea) were reported. 



Soybean. — Blight caused by Buctenum glycinemn was widespread. 

 Mosaic occurred in vaiiety test plots and greatly lowered the yield 

 of seed (11). 



Spinach. — Brown reported mosaic severe in the market gai'den win- 

 ter crop near Evansville. 



Strawberry. — Leaf-spot, caused by MycospJiaeyella fragariae, was 

 very serious. It was also noted on cinciuefoil. A Sclerotinia .stem rot 

 was found in .June. 



Sweet Potato. — Fusarium wilt and black rot {Ceratostuijiella fim- 

 briata) were noted. 



Tomato. — Leaf-spot, caused by Se]>toria, lycopersici, was serious in 

 the canning crop in central and especially southern Indiana and in 

 gardens. The worst defoliation was noted on the poorer soils in Gib- 

 son County. The summer drouth tended to check the disease. 



The hot dry summer was favorable to wilt, caused by Fusarium 

 lycopersici, which was the most destructive disease of this crop this 

 year. In the canning crop the disease was associated with the use of 

 southern-grown plants. Evidence was obtained that the fungus persists 

 four years in the soil. Mosaic was generally prevalent in fields and 

 greenhouses and was more or less associated with the weed carriers (4). 

 Fruit lesions wei'e not uncommon. In field tests at Kempton the 

 eff'ectiveness of eradication of the weed hosts, Physalis species, was 

 shown. 



