44 CONNECTICUT EXPERIMENT STATION REPORT, 1912. 



CONDENSED RESULTS OF INOCULATIONS WITH ENDOTHIA 

 GYROSA AND ENDOTHIA GYROSA PARASITICA. 



E. g. parasitica from Cast, on Cast. dent, seedl. . . 



44 4l 44 44 sprts. . . 



14 l4 Quer? sp. seedl. . . 



44 44 " " sprts. . . 



Querc. on Cast. dent, seedl. . . 



44 44 4 ' 44 sprts. . . 



44 44 Quer. sps. seedl. . . 



44 44 4 ' 44 sprts. . . 



. gyrosa Cast, on Cast. dent, seedl. . . 



44 * 4 44 44 sprts. . . 



44 ' 4 Quer. sps. seedl. . . 



44 44 4I 44 sprts. . . 



Querc. on Cast. dent, seedl. . . 



44 44 44 44 sprts. . . 



44 44 Quer. sp. seedl. .. 



44 4< 44 44 sprts. . . 



Checks on all Castanea. . 



Checks on all Quercus . . 



Inoc. 



(No.) 



Failed 

 (No.) 



177 



55 



12 



I 



16 

 20 



12 

 15 



18 



5 

 o 

 82 

 4 

 5 



"3 



J 5 i 



86 

 14 



12 



21 



I6 11 



20 



7 



15 

 18 



5 



o 

 Si 



3 



5 

 19 



Took 



(No.) 



9 1 5i 



4i 75 



o 



1 \ ioo 

 4 i 16 



o 

 o 



42 



o 

 o 

 o 

 o 



I 



25 

 o 

 o 

 o 

 o 



'Kept moist. * Kept dry. 2 - a One dry, one moist. 3 Culture originally 

 from conidial spores. 4 Culture from ascospores. 5 Trees ridged to produce 

 drought conditions. 6 Trees unridged. 'Inoculated above and below kmfe 

 girdle. 8 Cut above and below knife girdle, but not inoculated. 'Stem in- 

 oculated underground. 10 Stem cut underground, but not inoculated. n If 

 done earlier in the season, possibly some would have taken. These foot- 

 notes apply chiefly to large table ; see column " Host Inoc." for numbers. 



on August 4, 1909, which produced only 50 per cent, infection 

 .as against 100 per cent, produced by a culture over two years 

 younger obtained from Washington, D. C, on January, 2, 1912. 

 Both of these were of the same spore age, and inoculated into 

 chestnut seedlings at the same time and place. 



That the age of the spores used affects their virulence is 

 apparently shown in a number of our inoculations. We used 

 spores from cultures that had been made all the way from*2O to 

 100 days, in a few cases even 250 days. These spores were always 

 somewhat moist when used, and though possibly some of them 

 were too old to germinate, there must have been others that 

 were not, since we have renewed cultures not infrequently that 

 were 100 days old, and in one case a culture that was 399 days 

 old. Our inoculation tests apparently indicate that the younger 



