Experimental Error in Crop Tests 
39 
was 100:99. Due to competition, the University No. 3 
yielded relatively 8.0 per cent too low, in single rows and 
within the same hill it yielded 1 per cent too high. The ap- 
parent lack of competition within the hill in this case may 
have been due to there being only two plants of rather similar 
type in a hill. 
When all three varieties were compared in the same hill 
the relative yields for the Hogue's Yellow Dent, University 
No. 3, and Pride of the North wxre respectively 100, 96, and 
28, as compared with 100, 98, and 53 in the center rows of 
three-row plats, and 100, 90, and 38 in single-row plats. 
In the three-row plats (Table 16), the yields indicate 
that competition affects the outer rows to such an extent that 
they should be discarded in all yield tests of corns which dif- 
fer in growth habit. Single-row plats are unreliable for a 
comparative test of corn differing in growth habit or rate of 
planting. Tw^o-row plats would probably be subject to one- 
half of the competition of single-row plats. 
In 191^ (Table 17), inbred and first generation hybrid 
Hogue's Yellow Dent corn were similarly compared in (1) 
alternating single rows, (2) alternating three-row plats, and 
(3) in the same hill. The inbred corn had been self-fertilized 
Table 17 — Relative yields of inbred Hogue's Yellow Dent corn 
and first generation hybrid seed of inbred strains ivhen 
compared in three-rotv plats, single-row plats, and when 
planted in the same hill (1916) 
Manner of planting 
Plants 
per hill 
No. of 
replica- 
tions 
Yield per acre 
Actual Relative 
Cross- 
bred 
Inbred 
Cross- 
bred 
Inbred 
Bus- 
Bus- 

Per 
Per 
hels 
hels 
cent 
cent 
Crossbred and inbred strains 
of H. Y. D. corn alternat- 
ing in 3-row plats 
4 
9 
76.2 
28.1 
100 
36.9 
Crossbred and inbred strains 
of H. Y. D. corn alternat- 
ing in single rows 
4 
6 
90.5 
28.0 
100 
31.1 
Crossbred and inbred strains 
of H. Y. D. corn planted 
in the same hill* 
4 
300 
54.0 
11.2 
100 
20.7 
' Where two plants each of two types were grown in the same hill, the 
actual yield for each type is given, based on the rate of two plants per hill. 
