CITRUS scab: its cause and control. 



25 



Table 7. — Results of inoculations ivith the scab fungus on expanding leaves of grapefruit, 

 King and Satsuma oranges, tangerine, lemon, and tangelo. 





Size, 

 width 













Per- 









of 



Total 



Drop- 

 ped. 



Leaves 



Total 



Total 



cent- 







Date. 



leaves 

 (in six- 

 teenths 



inocu- 

 lations. 



re- 

 main- 

 ing. 



posi- 

 tive. 



nega- 

 tive. 



age, 

 posi- 

 tive. 



Degree of infection . 







of an 





















inch). 



















Grapefruit: 





















May 1,1917.... 



(1) 



50 



9 



41 



28 



13 



68 



Very severe. 





May 21, 1917... 



0) 



40 



5 



35 



26 



9 



74 



"Do. 





Feb. 3, 1919.... 



0) 



16 







16 



16 







100 



Do. 





Feb. 19, 1919... 



(1) 



4 



3 



1 







1 











Feb. 20, 1919... 



(1) 



5 







5 



5 







100 



Do. 





Do 



(1) 

 (1) 

 (1) 



5 

 4 

 11 



4 

 1 

 



1 

 3 

 11 



1 

 3 



8 





 

 3 



100 

 100 

 73 



Do. 

 Do. 



Very severe; 16 hours 





Do 





Feb. 28, 1919... 



ex- 



Mar. 3, 1919. . . . 



(}) 



15 



2 



13 



10 



3 



77 



posure. 



Very severe; 4 hours 



ex- 



Do 



(}) 



S 



4 



4 



3 



1 



75 



posure. 

 Very severe; 11 hours 



ex- 



















posure. 





Jo 



0) 



7 



3 



4 



3 



1 



75 



Very severe; 6 hours 



posure. 

 Royal grapefruit. 



ex- 



Apr. 18, 1919. . - 



« 



10 







10 



. 



10 









Apr. 22, 1919... 



(1) 



20 



4 



16 



8 



8 



50 



Severe. 





Apr. 29, 1919... 



(') 



13 







13 



13 







100 



Do. 





Do. 



(!) 



(1) 



7 

 18 



1 

 2 



6 

 16 



5 

 



1 

 16 



84 

 



Do. 



Royal grapefruit. 

 Severe. 





Do 





Apr. 2, 1920 



(1) 



36 



5 



31 



23 



8 



74 





Apr. 5, 1920 



(1) 



36 



5 



31 



23 



8 



74 



Do. 





Apr. 6, 1920... - 



0) 



20 



1 



19 



15 



4 



79 



Do. 





Mar. 8, 1919.... 



4 to 64 



12 



3 



9 



3 



6 



33 



16 hours exposure. 





Mar. 12, 9919... 



6 to 20 



15 







15 







15 











Mar. 13, 1919... 



8 to 16 



14 







14 







14 











Apr. 14, 1920... 



8 



39 







39 







39 











Apr. 10, 1920... 



8 to 16 



23 







23 







23 











Mar. 8, 1919.... 



8 to 48 



9 



5 



4 







4 







Do. 





Apr. 10, 1920... 

 Mar. 12, 1919... 



8 to 16 



20 







20 







20 







Royal grapefruit. 





8 to 20 



10 







10 







10 











Apr. 16, 1920... 



12 



32 







32 







32 











King orange: 





















Feb. 28, 1920... 



(^) 



10 







10 



9 



1 



90 



Severe. 





Apr. 5, 1920 



(1) 



50 







50 



10 



40 



20 



Moderate. 





pr. 20, 1920... 



4 to 8 



61 



7 



54 







54 











Apr. 16, 1920... 



8 



50 



10 



40 







40 











Satsuma orange: 





















Mar. 26, 1919... 



(1) 



30 



4 



26 



21 



5 



81 



Do. 





Mar. 12, 1919... 



(1) 



9 







9 



7 



2 



78 



Do. 





Mar. 19, 1919... 



8 



20 



5 



15 







15 











Mar. 13, 1919... 



8 



4 







4 







4 











Mar. 12, 1919... 



8 to 24 



8 







8 







8 











Tangerine: 





















Mar. 3, 1919...- 



(1) 



5 



1 



4 



4 







100 



Do. 





Apr. 10, 1920. . . 

 Mar. 12, 1919... 



8 



14 







14 







14 











8 to 16 



16 







16 







16 











Lemon: 





















Feb. 19, 1919... 



m 



12 



4 



8 



8 







100 



Very severe. 



16 hours exposure. 





Do 



(1) 

 (1) 



7 

 4 



3 

 



4 



4 



4 

 4 





 



100 

 100 





Feb. 28, 1919... 





Mar. 1,1919.... 



(1) 



4 







4 



4 







100 



Very severe. 





Do 



(1) 

 (1) 



2 

 2 





 



2 

 2 



2 



2 





 



100 

 100 



Severe. 

 Do. 





Mar. 3, 1920.... 





Do 



(1) 

 (1) 



3 

 5 



2 

 



1 

 5 



1 

 4 





 1 



100 

 80 



Do. 



Moderate. 





Apr. 5, 1920 





Apr. 10, 1920... 



4 to 8 



17 



2 



15 



1 



'14 



7 



Very slight. 





Apr. 15, 1920... 

 Mar. 12, 1920... 



8 to 12 



24 



4 



20 







20 











8 to 16 



12 







12 







12 











Mar. 20, 1920... 



12 



20 



2 



18 







18 











Tangelo: 





















Jan. 31, 1919.... 



(^) 



4 



2 



2 



2 







100 



Very severe. 





Mar. 3, 1919.... 



(1) 



25 



5 



20 



20 







100 





Feb. 28, 1919... 



(1) 



10 







10 



10 







100 



Do! 





Feb. 3, 1919.... 



(}) 



16 







16 



16 







100 



Do. 





June 2, 1920 



(1) 



20 



5 



15 



12 



3 



so 



Moderate. 





June 7, 1920 



4 to 8 



25 



2 



23 







23 











Mar. 12, 1919... 



6 to 16 



15 







15 







15 











Apr. 10, 1920... 



Stole 



19 







19 







19 











Apr. 16, 1920... 



12 



30 



4 



26 







26 











^ Expanding. 



