PAPERS OX BIOLOGY AND AGRICULTURE 149 



tlie damage from the two smuts of broom corn ap- 

 peared much less than that due to the bacterial disease. 

 One bad outbreak of alfalfa leaf spot, caused by 

 Pseudopeziza medicag'inis, appeared in St. Clair county, 

 and Jonathan spot on apples appeared to be a serious 

 problem in Vermilion county, as was also tomato wilt 

 caused by Fusarium Ii/copersicae. 



XEW DISEASES 



During the season of 1921 there came to our attention 

 several diseases not hitherto reported in Illinois. Sev- 

 eral of these diseases occurring on fruits, vegetables and 

 ornamentals are described in a paper by Dr. H. W. An- 

 derson and need not be discussed here. 



Along the lake shore north of Lake Blulf in Lake coun- 

 ty, several greens on an expensively built golf course 

 were being very badly damaged through the attack of 

 Bliizocionia solan i. Often the loss would be as much as 

 $500 for a single green since great care was being exer- 

 cised in caring for the course, and especially imported 

 seed of the New Zealand fescue grass was being used for 

 seedage. This troublesome disease has hitherto been re- 

 ported only from the neighborhood of Washington, D. C, 

 and it seems unlikely that in Illinois the disease will be- 

 come of more than a local importance. The parasite caus- 

 ing the disease seems to be a normal inhabitant of forest 

 soils, and is readily transplanted from woodlands to golf 

 courses or grass plots in the neighborhood. The parasite 

 seems to be spread from green to green on the golf course 

 by the shoes of the players and caretakers, and its de- 

 velopment and spread on the green itself furthered by 

 the presence of abundant moisture. On greens not wholly 

 level the course of the spread of infection corresponds 

 strikingly with the course of water used for irrigation. 

 Cool moist nights appear to favor the development of the 

 fungus, and in the mornings it can usually be detected as 

 a thin, cobwebby film of fungous h^i^hae running among 

 the leaves of the grass. The collection of dew among its 

 mycelial strands gives it the appearance of a fine cloud 

 lying in the grass. The heat of the sun on a bright diy 

 day seems sufficient to stop the advance of the fungus. 



