314 



SCIENCE 



[N. S. Vol. XLII. No. 1079 



considerable Tineveniiess of the stand, there 

 being quite a proportion of very weak plants. 

 It was known during the season of 1914 that 

 these fields were infested by the wheat straw 

 worm, Isosoma grande Riley, and it was 

 thought that the weakened plants were due to 

 infestations of this insect. Careful examina- 

 tion, however, did not reveal the presence of 

 larvse in the unthrifty plants. While making 

 observations two weeks previous to this time 

 it was noted that the emerged females of the 

 wheat straw worm, Isosoma grande, were ovi- 

 positing in the wheat plants, and it was nat- 

 urally our first thought, on examining the 

 fields the second time, that the weakening of 

 the plants was due to the attack of the larvse. 

 It may be said in passing that the wheat plants 

 were largely volunteer, although some addi- 

 tional seed had been sown in the field. 



A number of these plants were carefully ex- 

 amined in the laboratory and it was found 

 that the attached wheat kernels were infected 

 with a fungus which had apparently destroyed 

 their contents at or near the time of germina- 

 tion. Pure cultures of the organism were 

 made and it was found that the fruiting was 

 typical in every respect excepting on nutrient 

 agar cultures, or cultures which tended to be- 

 come dry too readily. 



A search of the literature indicates, in so 

 far as I have been able to determine, that this 

 disease has not been heretofore noted and that 

 the organism has not been previously de- 

 scribed. The fungus clearly belongs to the 

 genus Podosporiella. We find only one other 

 species under this genus, namely, Podospori- 

 ella humilis EU. & Ev. The fungus is not 

 truly parasitic, but seems to attack the wheat 

 kernel about the time of germination, com- 

 pletely destroying the contents in very much 

 the same way that the kernel is destroyed by 

 smut. The result is that the wheat seedling, 

 not getting the proper food supply in the early 

 stages of growth, is permanently dwarfed and 

 produces few stools. The crop yield is much 

 reduced. 



An extended description of the fungus and 

 the characteristics of the disease will be given 

 in the near future, at which time the fungus 



will be named as a new species of Podospori- 

 ella. P. J. O'Gara 



OCCUEEENCE OF THIELAVIA BASICOLA AS A ROOT 

 PARASITE OF WATERMELONS IN THE SALT 

 LAKE VALLEY, UTAH 



During the current season my attention was 

 called to a serious trouble of watermelons, 

 Citrullus vulgaris Schrad., in which all the 

 plants in an entire field had been lost and even 

 a second planting had largely died. Many of 

 the plants came above the ground in an ap- 

 parently healthy condition, but soon wilted or 

 '■ damped off." Some that did not wilt had a 

 ehlorotic appearance and upon carefully re- 

 moving them from the soil it was found that 

 the lower part of the root system had been de- 

 stroyed. These plants had developed many 

 lateral roots above the point of injury. Ex- 

 amination showed that the roots were badly 

 infected with the fungus Thielavia hasicola 

 (B. & Br.) Zoph. In going over the litera- 

 ture I fiind that Gilbert^ gives a considerable 

 list of hosts and the distribution of the 

 fungus. This list does not include the water- 

 melon and it is therefore apparent that the 

 watermelon is a heretofore unreported host 

 for this fungus. So far as the writer has been 

 able to determine, Thielavia hasicola has not 

 been found in any part of the United States 

 west of the Mississippi River; at least, it has 

 not been found as an active parasite. 



The fungus has been isolated in pure cul- 

 ture and has fruited characteristically, agree- 

 ing perfectly with the descriptions as given in 

 the literature. P. J. O'Gaea 



OCCURRENCE OF THE BACTEEL4L DISEASE OF SUDAN 

 GRASS IN THE SALT LAKE VALLEY, UTAH 



Only very recently has Sudan grass, Andro- 

 pogon sorghum, been introduced into Utah, 

 and with it apparently has been introduced 

 the bacterial disease. Very recently some 

 specimens were brought to the laboratory for 

 examination, where it was found that they 

 were badly diseased. The elongated, red- 

 brown blotches were extremely numerous and 

 had caused the death of many of the leaves. 



1 Bulletin 158, Bureau of Plamt Industry, IT. S. 

 Department of Agriculture, October 7, 1909. 



