Indiana Plant Diseases, 1921 199 



also powdei-y mildew (Phylluctiniu corijlea) on chestnut foliage. H. F. 

 Dietz reported chestnut blight due to Endothia parasitica in a nursery 

 near Wabash and in a chestnut orchard in Spencer County. A leaf-spot 

 of mulberry due to Mycosijhaerella inorifoUa was noted in Fulton County. 

 Powdery mildew (Microsphaera alni) occurred on a Russian oak (Q. 

 peduncidata) on the Purdue campus. Anthracnose of sycamore caused 

 by Gno)>ionia veneta was noted near Lafayette in May and specimens of 

 twig, petiole, and leaf blade infection were sent in from Evansville 

 the same month. 



Ornamentals. — Aster wilt, due to Fusarium conglutinans callistephi 

 (2) was very severe during June and July and many florists and owners 

 of home gardens complained of this disease. Carnation rust (Uromyces 

 caryophilinus) was as usual prevalent in greenhouses as was also snap- 

 dragon rust (Puccinia antirrhini) . Jackson found crown-gall on culti- 

 vated yarrow {Achillea ptarmica) and reported (Mycologia 14: p. 119) 

 a rust (Puccinia emiliae) on pot marigold (Calendula officinalis) . Sweet 

 peas in a greenhouse were very badly injured by a powdery mildew 

 which in early May was causing the premature death of the plants. 

 Downy mildew (Pseudoperonospora cubensis) was found on the leaves of 

 a Cucurbita gourd in Fulton County. Roses were generally and se- 

 verely injured by powdery mildew (Sphaerotheca panyiosa) and com- 

 plaints were received from eight counties. Burkholder reported a fair 

 control of both powdery mildew and black spot (Diplocarpon rosae) 

 under outdoor conditions by spraying with a 2-4-50 Bordeaux. 



Summary. 



The diseases of outstanding importance as observed in 1921 were 

 the Fusarium soil troubles, the mosaic diseases, apple scab and blotch, 

 cantaloupe and cucumber bacterial wilt, peach bacterial spot, and to- 

 mato leaf-spot. 



The diseases found in 1921 which have not, as far as could be ascer- 

 tained, been previously recorded for Indiana are as follows: Ampelop- 

 sis (two species) leaf-spot — Gtdgnardia hidivellii; apple fruit rot (Pliy- 

 tophthora cactorum) and brown bark spot; lima bean powdery mildew 

 and Fusarium seed stain; sugar beet root rot; cantaloupe fruit rot (Fu- 

 sarium) ; celery mosaic; chestnut powdery mildew (Phyllactinia corylea) 

 and blight (Endothia parasitica); clover root rot (Fusarium), mosaic, 

 and powdery mildew; cowpea bacterial spot, powdery mildew, and leaf- 

 spot, Cercospora cruenta; eggplant fruit rot, Pliytophthora terrestris; 

 goldenseal blight, Botrytis; Cucurbita gourd downy mildew, Pseudope- 

 ronospora cubensis; lettuce, Botrytis crown rot and Rhizoctonia rosette; 

 hard maple, Rhytisma punctatuni; pot marigold rust, Puccinia etniliae; 

 mulberry leaf-spot, Mycosphaerella morifolia; parsnip leaf-spot, Cerco- 

 sporella pastinacae; pea. Bacterium pisi; peach, Leptothyrium pomi on 

 twigs; pear sooty blotch; pepper fruit rot, Phytophthora terrestris; 

 privet powdery mildew, Microsphaera alni; radish root invasion by 

 Peronospora parasitica; spinach crown rot (Phytophthora), root-knot, 

 and downy mildew (Peronospora effusa) ; squash Gloeosporium storage 

 rot; tomato collar rot; turnip yellows, Alternaria leaf-spot, and powdery 

 mildew; wheat, Ophiobolus graminis. 



