Indiana Plant Diseases, 1922 209 



Early blight, caused by Alternaria solani, caused a collar-rot in 

 the field in Hancock County as a result of plant-bed stem lesions, and 

 also a prevalent spotting of the late-set fruits. These fruit spots were 

 oval or circular, with an even margin, sunken, smooth, black or brown 

 in color and in no way resembled the nailhead spot of the south. Leaf 

 mold, caused by Cladosjjorium fulvum, was very destructive in green- 

 houses and was noted sparingly in the field. Buckeye rot, caused by 

 Phytophthora terrestris, was serious on the low-hanging fruits in certain 

 greenhouses. It did not occur in the field where it was serious in 1921 

 (10), however. 



Seed disinfection combined with unfavorable dry weather rendered 

 basterial spot, caused by Bacterium vesicatorium, very uncommon (6). 

 Bacterial wilt, caused by Bacillus solanaceai-uvi, was found in a green- 

 house in Cass County in May causing the death of the plants. The 

 pith and vascular elements were brown and watersoaked and the lower 

 leaf petioles were reflexed as Dr. E. F. Smith has pointed out (13, 

 p. 179). There were brown or black surface lesions along the upper 

 side of the petioles. The causal organism was isolated and its patho- 

 genicity proved. Bluish pigment formation was shown by colonies on 

 potato dextrose agar. 



Anthracnose of the ripe fruit due to Gloeosporium phomoides was 

 very abundant in the canning crop in October. Nematode root-knot was 

 serious in greenhouses and was found in a few fields. Blossom-end 

 rot was not particularly severe. Hollow stem in the young plants was 

 more common than usual. Lightning injury (1) was found in one field. 



Watermelon. — Anthracnose {Colletotrichiim lagenariuni) was less 

 prevalent than usual, due to the dry weather, while the heat favored 

 the wilt, due to Fusarium niveum. The leaf -spot, due to Alternaria 

 brassicae nigrescens, was noted. Blossom-end rot occurred rather 

 commonly. 



Wheat. — Loose smut (Ustilago tritici) was very serious where un- 

 treated seed was used. Covered smut (Tilletia laevis) was of minor im- 

 portance. Stem rust (Puccinia graminis) was severe only near bar- 

 berries, according to K. E. Beeson, who reports four serious and two 

 minor outbreaks in the state this year. These were in Rush, Decatur 

 and Johnson counties. Mains reports leaf rust {Puccinia triticina) the 

 most serious wheat disease of the season, causing a reduction in yield 

 of about 7 per cent. It was worst in the southern third of the state. 



Scab, caused by Gibberella sa^ibinetii, occurred only rarely. An- 

 thracnose (Colletotrichum cereale) was not serious. Septoria leaf-spot 

 was found near Laporte by Kendrick, causing a yellowing and stunting 

 of the young plants. Powdery mildew (Erysijihe graminis) occurred 

 to a slight extent. Rosette was found in Laporte County by Kendrick. 

 Jackson found a small amount of foot-rot on the farm in Knox County 

 where he found Ophiobolus go-aminis in 1921. 



Forest and shade trees. — Among trees, the following diseases should 

 be recorded: Powdery mildew of catalpa from Floyd County; chestnut 

 blight, due to Endothia parasitica, in a nursery at Lafayette; cedar 

 rust on flowering crab; Penicillium and Fusarium rots of hickory nuts; 



14—27933 



