STERILITY OF OATS. 



pension retarded growth more than the sterile water. In a number 

 of cases the panicles did not push out of the sheaths, remaining un- 

 developed inside, and were so moldy that it was practically impos- 

 sible to make counts. How much the mold had to do in retarding 

 development could not be determined. Counts from these panicles 

 are given where possible. 



Table IV. — Relation of halo blight and stripe organisms to sterility in oats, as shown 

 by inoculation experiments with Wisconsin Pedigree 5 (Swedish Select) at Madison, 

 Wis., June '25, 1920. 



[The extreme and average percentages of sterility are shown in boldface figures.] 





Normal and sterile spikelets in treated and untreated panicles . Inoculum in sheaths. 





Untreated. 

 bundle 1. 



Sterile water. 



Halo-blight organism. 



Stripe or- 



Panicle. 



Bundle 2. 



Bundle 3. 



Bundle 4. 



Bundle 5. 



bundle 6. 





o 

 E-i 



53 



6 



o 



Ster- 

 ile. 



"3 

 o 



Eh 



22 

 30 

 37 

 25 

 33 

 9,1 



2 



3 



12 

 18 

 23 

 13 

 18 

 15 

 25 

 11 

 12 

 13 

 12 

 16 

 26 

 19 

 10 

 15 

 13 



Ster- 

 ile. 



~3 

 o 



e 



31 

 34 

 20 

 20 

 20 

 11 

 30 

 22 

 28 

 19 

 27 

 21 

 23 

 28 

 25 

 15 

 24 

 29 

 20 

 24 

 33 

 33 

 26 

 22 

 24 



o 



18 

 13 

 9 

 10 

 8 

 3 

 16 

 13 

 11 

 7 

 9 

 8 

 9 

 16 

 9 

 7 

 14 

 16 

 10 

 10 

 18 

 17 

 13 

 14 

 12 



Ster- 

 ile. 



"3 

 +^ 

 o 

 E-< 



17 

 16 







10 

 10 

 



Ster- 

 ile. 



75 

 



e 



"27 

 12 

 21 



28 

 19 



"21 

 21 

 32 



'cfj 



a 

 



10 



18 

 11 

 14 

 13 

 11 

 

 13 

 10 

 17 



Ster- 

 ile. 



73 

 

 Eh 



"3 

 c 



5 





 12 





 31 

 30 



5 



Ster- 

 ile. 





IB 



14 

 13 

 12 

 21 



9 

 12 

 12 



4 



2 

 12 

 13 



7 



1 

 o 



Ut 



a 

 PM 



26 

 20 

 20 



44 

 16 

 21 



o 

 I 



10 

 12 

 14 

 12 

 15 



6 

 14 

 14 

 11 

 11 



9 



7 

 11 



9 



17 



1 



o 

 t-l 

 <D 



Ph 



45 

 40 

 37 

 48 

 45 

 27 

 35 

 56 

 47 

 45 

 42 

 30 

 29 

 32 

 61 

 21 

 56 



CD 



13 

 21 



11 



+■3 



s 



o 



a 

 Ph 



41 

 61 



14 



7 

 6 



1 

 





 Ph 



41 

 37 



100 

 50 

 55 

 42 



100 



100 

 54 

 52 

 52 



100 







"3 



Ph 





1 







No.l 



52] 38 

 64 51 





No. 2 



9 

 1 



7 

 15 

 8 



"8 

 11 

 15 



31 

 8 

 33 

 53 

 42 

 100 

 38 

 52 

 46 



"29 



'43 



46 



"i7 

 *i2 



16 



ino 





58 

 47 

 53 

 50 

 36 



46 

 26 

 U 

 38 

 ?4 



58 



100 



No. 4 



10' 50 

 12; 60 

 8 72 



No.5 



20 



28 



"22 

 19 

 23 



9 

 16 

 

 

 10 

 9 

 11 

 

 4 

 8 

 8 



11 

 12 



"l2 

 10 

 12 



?7 



No.6 



34 



No.7 



33! 39 

 16 25 

 4| 23 

 27: 24 

 21 1 21 

 12 23 



14 

 9 

 17 

 12 

 18 

 13 

 14 



46 

 40 

 60 

 63 

 66 

 61 

 60 





No. 8 



25! 21 

 43 1 41 

 44 32 

 41 28 







No. 9 











No. 10 











No. 11 











No. 12 



58 



51 



















No. 13 





37 

 28 

 26 

 19 

 30 



















No. 14 







" 





12 42 























No. 15 











16 

 8 

 10 

 13 

 10 

 14 

 15 

 16 

 13 

 8 

 12 



64 

 53 

 41 

 44 

 50 

 58 

 45 

 48 

 50 

 36 

 50 























No. 16 































No.17 

































No.18 





... 

 ... 





























No. 19 









































No. 20 









































No. 21 







































No. 22 







































No. 23 























::' 

















No.24 







































No. 23 

















































































47 36 



10 21 



27 



15 



11 



40 



24 



11 



12 



52 









or, 









44 









a 



































GENERAL SUMMARY. 



Considerable sterility occurs on oat panicles without any apparcn 

 connection with halo blight and in fields where there are no bacterial 

 lesions. The amount seems to vary with different varieties of oats, 

 some showing more sterility than others during tho same season under 

 similar conditions. 



The amount of sterility does not appear to be in proportion to 

 susceptibility to halo blight. Wisconsin Pedigree No. 14 oats is tho 

 m<> I u ceptible to halo blight of the 11 varieties tested, but does not 



