Experimental Error in Crop Tests 
25 
Table 7 summarizes the two years' data with Kherson 
and Swedish Select oats. In 1913 the Swedish Select yielded 
18 per cent less than the Kherson when grown in alternating 
single-row plats, and 23 per cent less in alternating five-row 
plats. In alternating single rows the Swedish Select yielded 
relatively 7 per cent too high. 
In 1914 the Swedish Select yielded 89 per cent as much 
grain as Kherson in alternating single-row plats and 93 per 
cent as much in five-row plats. The Swedish Select straw 
yielded 13 per cent more in alternating rows and 17 per cent 
more in five-row plats. 
EVIDENCE OF PLAT COMPETITION IN A ^VHEAT-BREEDING NURSERY 
During the four years, 1910, 1911, 1912 and 1914, 80 
strains of Turkey Red wheat were tested at the ordinary 
field rate of seeding in identically the same order each year, 
in single 16-foot rows ten inches apart. The entire series 
has been replicated ten times each year. It is probable that 
many of the yields have been subject to the effect of row com- 
petition. 
Table 8 contains a concrete example of competition be- 
tween strains in such a wheat-breeding nursery. In the four- 
year row test of 80 strains, strain No. 75 ranked 80, while 
strains No. 74 and No. 76 on either side ranked 1 and 5. 
Strain No. 75 is a slightly shorter and thinner stooling type. 
To determine whether the relative rankings of these strains 
might have been influenced by competition, they were com- 
pared in both rows and blocks for two years, 1915-1916. 
Table 8 — Relative yields of three Turkey Red wheat strains 
when compared in five-row nursery plats and in single- 
row plats. Two-year average (1915-1916) 
Relative yields 
Strain number 
Blocks 
Rows 
GRAIN 
74 
75 
76 
106 
100 
108 
126 
100 
123 
STRAW 
74 
75 
76 
110 
100 
102 
113 
100 
109 
