SOURCES OF APPLE BITTEE-ROT INFECTIONS. 



13 



that the resulting cankers nsuall}^ showed no differences in their 

 development. 



Types of the cankers produced en the Winesap and Jonathan 

 varieties are shown in Plate V, figures 4 and 5. 



Table I. — Results of inoculations of apple l>ra)iches with hiftcr-rot fungus 

 cultures at Arlington Farm, Ya., in 1916. 



Apple variety and date of 

 inoculation. 





Num- 



Age of 

 ibranch. 



ber of 

 inocu- 

 lated 





slits. 



Years. 





4 



3 



4 



3 



1 



3 



4 



2 



2 



2 



3 



2 



1 



4 



1 



4 



4 



2 



2 



2 



4 



2 



1 



4 



1 



4 



3 



4 



1 



2 



4 



2 



4 



2 



1 



4 



1 



4 



5 



4 



4 



2 



3 



2 



3 



2 



1 



5 



2 



5 



4 



2 



4 



2 



3 



2 



4 



5 



3 



5 



4 



2 



4 



2 



4 



2 



1 



4 



1 



4 



3 



2 



2 



2 



3 



2 



Width of blackened 

 band. 



On 

 Aug. 2. 



On 

 Aug. 29. 



Condition. 



On Aug. 29. 



On Nov. 20. 



Ben Davis: 



June 28 



Do 



Do 



July 13 



Do 



Do 



York Imperial: 

 June 28 



Do 



July 13 



Do 



Do 



Missouri: 



Jime28 



Do 



Do 



July 13 



Do 



Do 



Jonathan: 



June 28 



Do 



Do 



July 13 



Do 



Do 



Grimes: 



June 28 



Do 



July 13 



Do 



Do 



Winesap: 



June 28 



Do 



July 13 



Do 



Do 



Yellow Newtown 



June 28 



Do 



July 13 



Do 



Do 



Mm. 

 3 



2 to 5 

 5 to 13 



3 



1 to 5 



4 



1 to 5 



1 to 3 

 

 



to 1 



4 to 10 





 to 1 



4 



3 to 5 



1.5 











2 to 15 



30 



40 to 45 

 15 to 20 



1 



to 1 



15 



2 to 15 



10 



2 to 15 

 



5 to 10 



4 to 5 



30 



Mm. 



3 



5 



5 to 13 



5 



1 to 8 



1 to 3 

 

 



Margins intact. 



do 



do 



do 



do 



do 



Margins cracked 

 do 



-do. 

 -do. 



4 to 10 







4 



8 to 10 

 15 











2 to 15 



30 



40 to 45 

 15 to 20 



1 



to 1 



15 



2 to 15 



10 



2 to 15 







5 to 10 



4 to 5 



30 



Margins intact . . . 



Healing 



do 



Margins intact . 



Healing 



do 



Margms intact . 

 do 



.do- 

 .do. 



Margins cracked. 



do 



do 



do 



do 



.do. 

 .do. 

 .do. 

 .do. 

 .do. 



Healing 



do 



Margins cracked 



.do. 

 .do. 



Margins intact. 



Do. 

 Margins cracked. 

 Margins intact. 



Do. 



Do. 



Margins cracked; 

 callus formed. 



Do. 

 Healed. 



Do. 



Do. 



Margins nearly in- 

 tact. 



Healed. 



Healing. 



Margins nearly in- 

 tact. 



Margins intact. 

 Do. 



Healed. 

 Do. 



Margins Intact. 

 Margins nearly in- 

 tact. 



Do 



Do. 



Healed. 



Do. 

 Margins cracked. 



Do. 



Do. 



Do. 



Healed. 

 Margins cracked. 



Do. 

 Margins somewhat 

 cracked. 



Healed. 



Do. 

 Margins cracked; 

 healing. 



Do. 



Do. 



The following general notes on all the inoculations were made on 

 November 20, 1916, and on January 9, 1917 : 



Ben Davis. — Except in the case of the l-year-old branches, the margins of 

 cankers are intact. 



York Imperial. — Margins of cankered areas are separated from the bark of 

 living portion of branch, and callus is forming. 



