1916] PRITCHARD—SUGAR-BEET BREEDING 443 
tively uniform. The coefficients of variability presented in table 
XXVI were determined from 173 beet families of Morrison’s 
Kleinwanzleben grown at Madison, Wisconsin, in progeny rows 
of 40-50 beets each in 1912, and from 98 families of the same stock 
grown under similar conditions at Madison in 1973. 
TABLE XXVI 
VARIABILITY OF SUGAR-BEET FAMILIES 
Percentage of sugar 
Year Mean _| Standard devia cm 
TORQ cS 13.60+0,068 | 0.998+0.048 7.34 
FOES. es I5.4T%+0.058 | 1.009*0.041 6.54 
Yield of sugar per row 
Year Mean (gm.) Seasrueg es penare raat 
1913. 74. 4276. 26 32.67\637.08 23.00 14.90 
1013... 3 2074.70 19.64/288.18+ 13.88 13.89 
The average variability of progeny rows expressed in percentage 
of the mean was 6.54-7.34 for percentage of sugar, and 13.89- 
14.90 for yield of sugar. Although these constants are smaller than 
the coefficients obtained for individual beets of the same families, 
9.46-12.06 and 38. 58-49. 53 for percentage and yield respectively, 
they are fairly large for averages. 
The range for percentage and yield is not shown in the table, 
but rows containing 80-100 per cent stand varied from 10.1 to 
15.7 in percentage of sugar in 1912, and from 13.2 to 17.4 in 1913; 
while the extreme yields for the same periods were 2383-5654 and 
1423-2746 gm. respectively. Such differences certainly offer ample 
Opportunity for selection. 
EFFECT OF SOIL IRREGULARITIES UPON THE VARIABILITY OF 
BEET FAMILIES.—This was determined from the records of our 
sugar-beet breeding experiments in-which progeny rows and check 
tows were planted alternately. 
family differences exhibited in field tests may be due to 
several causes, some method had to be adopted for studying soil 
