Experimental Error in Crop Tests 
7 
10. In 1914, due to plat competition, Pride of the North 
corn yielded relatively 51 per cent too low when compared 
with Hogue's Yellow Dent in the same hill, while in alter- 
nating single-row plats it yielded relatively 28.3 per cent too 
low. 
In a comparison of University No. 3 with Hogue's Yellow 
Dent, the University No. 3 yielded relatively eight per cent 
too low in single-row plats, and within the hill it yielded 
relatively one per cent too high. The lack of competition 
within the hill in this case may have been due to there being 
only two plants of a rather similar type in a hill. When all 
three varieties were compared in the same hill, the relative 
yields for Hogue's Yellow Dent, University No. 3, and Pride 
of the North were respectively 100, 96, and 28, as compared 
with 100, 98, and 53 in the center row of three-row plats and 
100, 98, and 38 in single rows. 
11. In 1916, inbred Hogue's Yellow Dent corn which had 
been greatly reduced in vigor by five years of self-fertiliza- 
tion was compared with the more vigorous first generation 
hybrid of two such pure lines, in blocks, rows, and hills. Be- 
cause of competition with the larger plants in the same hill, 
the inbred corn yielded relatively 44 per cent too low, while 
in alternating single rows, it yielded relatively 16 per cent 
too low. 
12. Studies with oats, wheat, and corn suggest that the 
yield of the border rows of narrow, adjacent test plats may be 
materially affected by plat competition. 
13. When surrounded by corn hills having a full stand 
of three plants, two-plant hills and three-plant hills respec- 
tively yielded 10.5 per cent and 35 per cent more than a one- 
plant hill in 1914. In a similar test in 1917, two-plant hills 
and three-plant hills respectively yielded 67 and 102 per cent 
more than a one-plant hill. 
14. The average grain yield of a three-plant corn hill sur- 
rounded by a full normal stand of three plants per hill was 
465.8 grams in 1914. This yield per hill was increased 2.7, 
5.3, 13.1, and 43.1 per cent by the presence, respectively, of 
(1) one adjacent hill with two plants, (2) one adjacent hill 
with one plant, (3) one adjacent blank hill, and (4) two 
adjacent blank hills. In 1917 corresponding adjacent imper- 
fect hills increased the grain yield of three-plant hills, other- 
wise surrounded by a full stand, respectively 2, 9, 15, and 
25 per cent. 
