DEVELOPMEISTT OF TUBERS IN THE POTATO. 



19 



cance, so that the data present no conclusive evidence to show that 

 the weight of the tuber is dependent upon the length of the stolon 

 which bears it. 



Table V. — Correlation betiveen the length of each stolon and the weight of the tuber which it 

 produced in 55 hills of Charles Downing potatoes grown at Greeley, Colo., in 1918. 



[Coefficient of correlation,-0.112±0.052.] 





Weight of tubers (grams). 





Length of sto- 

 lon<^ (mm.). 



1 



to 

 25 



26 

 to 

 50 



51 

 to 



75 



76 

 to 



100 



101 



to 

 125 



126 

 to 

 150 



151 

 to 

 175 



176 

 to 

 200 



201 

 to 

 225 



226 

 to 

 250 



251 



to 

 275 



276 

 to 

 300 



301 

 to 

 325 



326 351 



to ', to 

 350 375 



376 

 to 

 400 



401 

 to 

 425 



426 

 to 

 450 



Fre- 

 anency. 



1 to 2.5 





2 



1 

 1 

 3 

 1 

 2 



"i' 



"5' 



1 

 2 

 1 

 I 

 1 



5 

 5 

 2 



1 

 3 



7 

 5 

 5 



8 

 7 



1 

 3 

 6 



4 

 2 



1 

 1 



J 



"3' 

 5 



"3' 



2 



1 

 2 

 2 

 ? 



"3' 



1 

 2 



1 

 1 

 2 

 1 



1 

 2 

 1 





2 



1 '. 







1 27 



26 to 50 



1 



1 

 1 

 2 

 1 



1 





2 







29 

 28 

 35 

 19 



51 to 75 



2 



"2 



1 







76 to 100 



2 1 



1 



1 





101 to 125 







126 to 1.50 



2 





1 



"2 















9 



151 to 175 

















10 



176 to 200 













1 









3 



201 to 225 . ... 





















1 









1 



226 to 250 . . 



























1 











251 to 275 





























1 













276 to 300. 

















1 











, 









1 



301 to 325 



























1 









1 





































Frequency. 



7 



11 



11 



18 



36 



18 



15 



13 



6 



6 



6 



3 



4 



4 



3 



1 



1 



163 



A further study of the data for the purpose of ascertaining whether 

 the length of the stolon and the size of the tuber are associated with 

 a definite position on the stem, included a grouping of the plants 

 having two, three, and four stolons, respectively, using only those 

 in which one tuber* was produced at each node. The summarized 

 results are shown in Table VI. 



Table VI. — Relation of the position of the stolon on the stem to the length of each stolon 

 and the iveight of the tuber which it produced, in 55 hills of Charles Downing potatoes 

 grown at Greeley, Colo., in 1918. 



Position of the stolon. 



Two stolons per hill : 



Lower stolon 



Upper stolon 



Three.stolon.s i)er hill 

 Lower, stolon . . .. 



Middlestolon 



I'pjx'r stolon. 



Four stolons jicr hill: 

 Loworstdlon . . . . 



Second stiilon 



Thini stolon 



Upper stolon 



Number 

 ofhiUs. 



Length 

 of the 

 stolon. 



Mm. 

 66.2 

 68.0 



45.4 



55.2 



106.6 



71.4 

 89.1 

 90.4 

 110.2 



Weight 

 of the 

 tuber. 



Grams. 

 210.3 

 175.4 



179.1 

 126.1 

 127.9 



119.4 

 138. 

 120.5 

 92.5 



It will be seen that while the original tabulations (Table IV) show 

 considerable fluctuation, the averages brought together in Table VI 

 indicate very consistently a high degree of relationship between the 

 position of the stolon and its length, the shortest stolons being 



