68 



BULLETIN 984, U. S. DEPARTMENT OF AGRICULTURE. 



Table IX. — Remits of the examination of damping-off foci in coniferous seed 

 beds for Pythium debaryanum, Corticium vagum, and Fnsarium spp. — Con. 



• 



Beds treated with 

 formaldehyde. 



Beds treated with 

 copper sulphate. 



[Beds treated with 

 zinc chlorid. 



All treated beds. 



Grouping. 



<6 



PI 



1 



03 



'o 



o 



Ph 



Number 

 showing — 



1 

 03 



X 

 <s 



'o 

 o 



Ph 



Number 

 showing — 



d 







03 



M 



IB 

 O 



Ph 



Number 

 showing — 



■d 



3 



.a 

 a 



03 

 « 



'o 



O 

 Ph 



5 



Number 

 showing — 





3 



Ph 



t-l 

 •o 

 O 



03 

 3 



Ph 



| 



2 



Ph 



o 



O 



8 

 a 



'u 

 03 



a 



Ph 



8 

 3 



Ph 



a 



a 



o 

 .O 



a 



a 



03 



3 



a 



a 



Ph 



5 



a 



a 



'a 



Fh 



o 



O 







a 



03 



3 

 Ph 



By locality: 

 Berkeley, Calif 







? 

































































Garden City, Kans. — 

 Garden City Nurseries. . . 

 Kansas Nurseries (sand) 



6 







6 



3 



1 











1 



3 



1 







3 



52 



31 



175 



1 



14 



11 



67 







8 

 2 

 3 

 



23 

 14 



34 



20 



1 



24 



6 



3 







5 



8 











. 5 



112 





































East Tawas, Mich. — 



























1 



32 



7 



1 

 20 

 2 





 13 











East Tawas Nurseries. . . 



8 



5 



4 







6 



5 



3 



3 



5 



3 







2 



7 

 3 































Total: 



48 

 100 



25 

 52 



5 

 63 



20 

 50 



11 

 23 



4 

 50 



7 

 18 



27 

 56 





 



27 

 68 



13 

 100 



8 

 62 



4 

 SO 



4 

 50 



3 

 23 



2 

 40 



1 



13 



9 

 69 



2 



40 



7 

 88 



16 

 100 



5 

 100 



11 

 100 



4 

 25 



3 

 60 



1 



9 





 





 





 



10 

 63 



2 



40 



8 

 73 



304 

 100 



120 



39 



20 

 9 



14 

 41 



12 



4 



161 





53 







By diagnostic methods: 

 Direct examination — 



8 

 100 



40 

 100 



5 

 100 



8 

 100 



34 

 100 



270 

 100 



18 

 53 



102 



38 



8 





?4 



Planted-plate cultures — 



1J>3 





57 







The data on the different nurseries do not allow any generalizing 

 on the basis of locality except to say that all of the fungi seem quite 

 generally distributed in the Lake States and Great Plains region. 

 In general, it appears that the Fusaria as a group are more common 

 than either of the other fungi ; as they grow more slowly than either 

 the Pythium or the Corticium, they were probably rather more 

 common relatively than even the plate-culture method indicated. 

 It also appears that the Pythium occurred in more foci than the 

 Corticium in the beds examined. Further culture work, perhaps 

 by the method of dilution plates of fragments of lesions, seems de- 

 sirable, especially in the East and the Northwest, regions in which 

 there are large coniferous nurseries and in which nothing like a 

 parasite census has been attempted. Observations on the type of 

 focus occurring in most of the nurseries in the Eocky Mountains 

 leads the writer to believe that Corticium will be found especially 

 important there. 



While the data on the fungi in foci in disinfected beds are insuffi- 

 cient to serve as a basis for much in the way of conclusions for any 

 individual treatment, they in general agree with the assumption, 

 which knowledge of the fungi would favor, that Corticium is the 



