Journal of Agricultural Research 
Vol, XI, No. 9 
418 
CONCLUSIONS 
The studies here reported show the necessity of the determination of 
field methods of technic in Plant Breeding and Farm Crops plot tests. 
Conclusive evidence is given which shows that in some cases there is 
considerable competition between rod rows of small grains when grown 
a distance of 1 foot apart. This has led to the adoption of three-row 
plots at University Farm. The results of a comparison of three-row 
plot yields with central rows show that central rows are as accurate a 
determination of yield as the use of all three rows. 
In a study of replications for rod rows of small grains considerable 
variability was shown for the different tests. In general three or four 
replications seem to be about as accurate a method as the use of any 
number below nine. The indications are that 9 to 12 replications would 
reduce error due to soil heterogeneity to a minimum. 
LITERATURE CITED 
(1) CarlEton, M. A. 
1909. limitations in field experiments. In Proc. 30th Ann. Meeting Soc. 
Prom. Agr. Sci., 1909, p. 55-61. 
(2) Cory, V. L. 
1910. the use of row plantings to check Field plats. In Proc. Amer. 
Soc. Agron., v. i, 1907/09, p. 68-70. 
(3) Harris, J. A. 
1915. ON A CRITERION OF SUBSTRATUM HOMOGENEITY (OR HETEROGENEITY) 
IN FIELD EXPERIMENTS. In Amer. Nat., v. 49, no. 583, p. 430-454. 
(4) Lyon, T. L. 
1912. SOME EXPERIMENTS TO ESTIMATE ERRORS IN FIELD PLAT TESTS. In 
Proc. Amer. Soc. Agron., v. 3, 1911, p. 89-114, 5 fig. 
(5) Mercer, W. B., and Hall, A. D. 
1911. THE EXPERIMENTAL ERROR OF FIELD TRIALS. In Jour. Agr. Sci., V. 4, 
pt. 2, p. 107-132, 9 fig. 
(6 ) Montgomery, E. G. 
1912. competition in cereals. Nebr. Agr. Exp. Sta. Bui. 127, 22 p., 7 fig. 
( 7 ) - 
1913. experiments in wheat breeding. U. S. Dept. Agr. Bur. Plant 
Indus. Bui. 269, 61 p., 22 fig., 4 pi. 
(8 ) Pearl, Raymond. 
1917. the probable error of a difference and the selection problem. 
In Genetics, v. 2, no. 1, p. 78-81. Literature cited, p. 81. 
(9) — and Miner, J. R. 
1914. a table for estimating the probable significance of statistical 
constants. In Maine Agr. Exp. Sta. Bui. 226, p. 85-88. 
(10) Piper, C. V., and Stevenson, W. H. 
1911. standardization of field experimental methods in agronomy. 
In Proc. Amer. Soc. Agron., v. 2, p. 70-75. 
(11) Pritchard, F. J. 
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In Jour. Amer. Soc. Agron., v. 8, no. 2, p. 65-81, 3 fig. 
