312 MASS. EXPERIMENT STAT1(«N BULLETIN 247 



Varieties of efrg])l;ints from different parts of the world have been 

 grown to determine their behavior to the pathogene. Numerous types 

 representing a large number of varietal names have been under observa- 

 tion but none has shown evidence of resistance to the disease. Since it 

 is believed that all distinct varieties have been grown and none has proved 

 of any merit for crossing, this phase of the problem has been discontinued. 



A pai)er mulch test conducted this year offered indication of being a 

 means of controlling the disease. Since infection rarely occurs above 

 an average temperature of 77°F., control of the disease by mulching the 

 plants with paper appears promising. 



Studies on the relation of soil reaction to infection and growtli of egg- 

 plants are in progress. 

 Fungous Pcirasites of Grasses. (VV. H. Davis). 



1. Sclerotium rhizodes Awd. is the cause of a sclerotial disease which 

 kills the leaves of grasses over large areas in meadows, pastures and lawns. 

 The disease is prevalent in Massachuetts and has been observed in all the 

 New England states. It appears in April and disappears in Jime of the 

 same year. It reduces the carrying capacity of pastures, cuts the hay 

 yield in meadows as much as 30 per cent and prevents grass plants from 

 maturing seed. The life-history of the fungus has been determined in part 

 and it is hoped that this phase of the study will be completed in the near 

 future. 



2. There appear to be two distinctly dift'erent diseases, each known 

 as "brown patch", which occur as dead areas in lawns and golf greens. 

 From one of these, which has been designated as "little brown patch", a 

 species of Fusarium has been isolated in five out of seven cases. This 

 Fusarium killed redtop seedlings grown in sterilized compost soil into 

 which the fungus was introduced. Collections of this disease have been 

 made in Massachusetts, Connecticut and New York. 



From the second and more common of these diseases, "large brown 

 patch", Rkizoctonia solani Kiihn has been isolated. Inoculations of grasses 

 with this fungus produced the characteristic disease when atmospheric 

 conditions were "warm and damp." Mercuric compounds controlled the 

 disease. 



3. "Snow mold" was observed on lawn grasses about the campus in 

 1927 and 1928 during the spring; it ai>]ieared also on golf greens and 

 fields. In 1927, it appeared first in February and continued until June. 

 The grasses were not seriously injured by it. Eleven specimens, three from 

 New York, one from Connecticut and seven from Massachusetts, showed 

 the fimgus to be a species of Fusarium. 



4. Striped smut of grasses {UntUapo strmeformis (Westd.) Niessl.) has 

 been studied during the last five years. Its life-history has been determined 

 and published. That there are biologic forms of the fungus was indicated 

 by the fact that spores from timothy did not infect redtop, and vice 

 versa. None of the agronomic strains of timothy ]>roved immime to this 

 smut, but some are more resistant than others. 



A Leaf-spot Disease of Chinese Cabbage, Caused by an Alternaria. 

 (W. H. Davis.) The disease has been observed each autumn since 1923. 

 Spores measure 5-29 x 7-103 microns as compared with those of A. hrassieae 

 (Berk.) Sacc. on common cabbage reported as 10-30 x 35-120 microns. 

 However, inoculations indicate that the two fungi are physiologically 

 identical. 



Other Activities. In the absence of an Extension specialist in the De- 

 partment, members of the staff are called upctn to render considerable ex- 



