Experimental Error in Crop Tests 
89 
lively 16.6, 26.7, and 50.8 per cent as much total dry matter 
as the one-rate, and their yield of ear corn was respectively 
2.8, 15.9, and 39.7 per cent as much per plant. 
An application of 1.55 pounds of manure per pot (Table 
46) increased the yields of total dry matter for the one, two, 
four and six-rates respectively 13.2, 15.3, 18.9, and 29.0 per 
cent. The yields of ear corn were 112.9, 128.3, 100.0, and 
257.0 per cent as large with manure as without manure in 
the one, two, four, and six-rates respectively. 
Table 46 — Summary of data showing the effect of different 
rates of planting upon growth of corn in pots. The 
results at the different rates of planting with manure are 
here expressed in per cent of the results without manure. 
Rogue's Yellow Dent corn (1915)* 
Rate of 
planting 
per pot 
Wt. moisture- 
free contents 
No. of 
pots 
Dry matter 
per plant 
Total 
leaf- 
area 
per 
plant 
Height 
of stalk 
Soil 
Manure 
averaged 
Ear 
Total 
Pounds 
Pounds 
Per cent 
Per cent 
Per cent 
Per cent 
1 
253 
1.55 
8 
112.9 
113.2 
109.2 
93.5 
2 
253 
1.55 
4 
128.3 
115.3 
95.3 
93.3 
4 
253 
1.55 
4 
100.0 
118.9 
110.6 
99.1 
6 
253 
1.55 
4 
257.0 
129.0 
120.6 
103.3 
*Data calculated from Table 44. 
STATEMENT OF METHODS IN BULLETINS 
A knowledge of the methods employed in crop testing is 
vital for intelligently evaluating the published results. With- 
out a statement of methods, the reader is obliged to assume 
that reliable methods were employed. Such an assumption 
is not warranted, since many methods used are known to be 
faulty. Not only the experiment station worker but the 
farmer as well should be given an opportunity to know in 
detail how the tests were made. Increased experimentation 
by farmers has led many of them to be interested in methods. 
The following brief summary table indicates the extent to 
which experiment station bulletins dealing with crop tests 
and published in the United States during the years 1900- 
1914 report details as to methods. A mere statement of re- 
sults is incomplete and does not carry conviction. 
