146 EXPERIMENT STATION. [Jan. 



A SPINACH DISEASE NEW TO MASSACHU- 

 SETTS. 



BY HARRY M. JENNISON, B.S. 



Early in the spring of 1910 the writer's attention was at- 

 tracted to a plot of winter spinach growing on the college 

 grounds which had been practically mined by a fnngns causing 

 a spotting of the leaves. The olivaceous color of the spots on 

 the diseased leaves suggested the possible presence of a Clad- 

 osporium as the causal organism, but upon microscopical exam- 

 ination the fungus was determined to be Heterosporium varia- 

 lilc, Cke. This organism is closely related to that causing the 

 Heterosporium disease of cultivated carnations, known as 

 "■ fairy ring." 



It was supposed that a disease which could so completely 

 devastate this crop would have been extensively reported, but 

 upon thorough search of the literature only a few references to 

 this particular spotting of spinach could be found. In 1905 

 Clinton ^ reports having collected in the open market in E^ew 

 Haven, (^onn., specimens of spinach leaves affected with the 

 above-mentioned fungus, and he refers to it as " leaf mold." 

 Ilalsted ^ in his investigations on the fungi attacking the 

 s])inach plant does not include Hetcrosporiii7n in his list. Since 

 1908 Tvced "^ has been studying its occurrence and injurious 

 effects in the truck crop regions of Virginia, where it causes 

 large losses annually to the truck farmers of that State. At 

 Amherst the disease was found infecting winter spinach, grow- 

 ing on two widely separated ]ilots. Immediately adjacent to 

 one of these was a considerable area set with young spinach 



' Clinton, G. P., Connecticut Agricviltural Experiment Station, report for 1905, Part V., p. 275. 

 ■ Halstead, B. D., New Jersey AsricuUural Experiment Station Bullotih No. 70, 1800. 

 ' Reed, H. S., in Virginia Agricultural Experiment Station circular No. 7, revised edition, 

 p. 80, 1910. 



