12 SOME FUNGOUS DISEASES OF ECONOMIC IMPORTANCE. 



Massachusetts, Rhode Island, Pennsylvania, and Maryland. From 

 all of these localities a disease was reported as causing a serious loss 

 to cultivators. The first collection of diseased plants made by one 

 of the authors was in the autumn of 1907 in Massachusetts. Many 

 plants were found to be in a very bad condition from an unknown 

 cause that apparently could not be the result of improper cultivation. 

 Upon pulling up the plants and cutting open the stems, in the lower 

 portion of the latter were found numerous greenish-black, flattened, 

 elliptical, hard bodies, sclerotia, averaging from 1 to 1^ centimeters 

 in length. The Botrytis stage was not apparent, but in cultures made 

 from a white mycelial layer lining the stems Botrytis paeoniae 

 promptly developed, and later sclerotia in great abundance. In fact, 

 a most remarkable phenomenon was the rapidity with which sclerotia 

 were formed, as in four or five days they had attained the size of 1 

 centimeter. 



While spraying with fungicides is to be recommended for the treat- 

 ment of the disease in its early stages, when the Botrytis stage is 

 apparent, it is not effective after the sclerotia by liberation from dis- 

 eased plants have infected the soil. At this stage, soil treatment is 

 the only efficient means of controlling the disease. Encouraging re- 

 sults have followed the use of lime when it was added to the soil in 

 the proportion of 500 pounds to the acre. Some authorities do 

 not consider this sufficient. In cases of marked acidity of the soil 

 the quantity of lime could be increased even to 2,000 pounds to the 

 acre. 



DISEASE OF CHRYSANTHEMUMS CAUSED BY BOTRYTIS. 



In the fall of 1908 some diseased chrysanthemums were received by 

 the Office of Pathological Collections and Inspection Work from New 

 York. The outer ray flowers were deformed and discolored and 

 fungous mycelium was found to be present in the tissues. A second 

 examination less than twenty- four hours after the specimens had 

 been confined in a warm, moist temperature revealed the presence of 

 Botrytis cinerea Pers. Cultures were made from the spores, and in 

 this case, as with the peonies, sclerotia developed in from four to 

 five days. Although this Botrytis species is recognized as being an 

 omnivorous form, it was truly parasitic in this instance. 



DISEASE OF CYCLAMEN CAUSED BY A VARIETY OF GLOMERELLA 



RUFOMACULANS. 



APPEARANCE OF DISEASED MATERIAL. 



Last season several collections of diseased cyclamen material from 

 a greenhouse in Alexandria, Va., were studied. There was no dif- 

 fused diseased area and the macroscopic appearance of certain spots 



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