548 Journal of Agricultural Research voi. xv.no. i* 



writer's cultures from Colorado and points farther east, but was easily 

 obtained from western yellow-pine seedlings growing in sterilized soil in 

 the plant pathological laboratory at the University of California. The 

 lesions on which it was first obtained occurred just above the soil sur- 

 face and produced the Botrytis spores directly on the lesions almost as 

 soon as the lesions themselves became evident. The spores and sporo- 

 phores appeared to be typical of B. cinerea. 



Inoculations had been made prior to this time with a culture of Botrytis 

 cinerea from apples from the Pacific Northwest furnished by Dr. J. S. 

 Cooky, of the Bureau of Plant Industry, The pots inoculated were kept 

 covered with glass plates from the time they were autoclaved until the 

 close of the experiment. Jack pine was used in the test, and the inocu- 

 lum was probably a mixture of cultures on steamed rice and prune agar 

 (record on this point is lacking). Parallel tests were made on three soil 

 types. On two of these the germination was very poor in all pots, and 

 damping-off was present in the controls as well as in the inoculated pots. 

 In the third soil type, a poor soil from Takoma Park, D. C, in which in- 

 oculations of Pythium debaryamum had proved unsuccessful, 44 seedlings 

 appeared in the five control pots during the first few days after germi- 

 nation began, while in the five pots of B. cinerea but two seedlings ap- 

 peared in the same time. Additional seedlings appeared later in both, 

 but with still approximately three times as many in the control pots as 

 in the pots inoculated with the fungus. Damping-off was somewhat, but 

 very little, heavier in the Botrytis pots. The experiment indicates ger- 

 mination loss as a result of the presence of B. cinerea, but must be re- 

 peated to give conclusive results. 



Mainly because of the known parasitic ability of B. cinerea on seedlings 

 of other plants and on older conifers and the strong indications of para- 

 sitism seen in the seedlings at the University of California, rather than 

 on the basis of the single inoculation experiment, it is believed that 

 this fungus will probably be sometimes found causing damping-off of 

 conifers. It is a fast-growing organism on prune agar, and failure to 

 obtain it at most of the nurseries at which -cultures have been made is 

 strong evidence that it is not present in the damped-off seedlings at 

 these places. Spaulding's failure to obtain it frequently from the seed- 

 lings with which he worked {26) is further evidence that in the East and 

 Middle West at least it is not important as a cause of damping-off of 

 conifers. 



MISCELLANEOUS FUNGI 



Alternaria sp. has been very frequently encountered in cultures from 

 dead coniferous material, both in the tender seedUng stage and in older 

 nursery stock. No inoculation tests with it have been made. It is not 

 believed to be important as a damping-off parasite, but its frequent 



