EXPERIMENTS IN FIELD PLOT TECHNIC 

 FOR THE PRELIMINARY DETERMINA- 

 TION OF COMPARATIVE YIELDS IN 

 THE SMALL GRAINS 



L. J. STABLER 



During recent years the investigation of the reliability of field 

 experiments has become an important phase of agronomic research. 

 Field experiments as ordinarily conducted have been shown to be 

 affected by many gross errors. In the light of these investigations it 

 has become apparent that the results of many of the older experiments 

 are inconclusive or even misleading. Various expedients have been 

 suggested for counteracting experimental error. Some of these have 

 been quite successful, while others have probably done more harm 

 than good. 



The pioneer investigations in this field have been of great 

 value in directing attention to the important sources of error and in 

 suggesting possible means for their control. Doubtless at the present 

 time most of the major sources of error are recognized. But the true 

 extent of the errors and the actual practical value of the methods of 

 counteracting them can be determined only by numerous investiga- 

 tions of experimental methods under different conditions. 



The present paper is concerned with experimental error and field 

 plot technic in preliminary variety and strain tests with the small 

 grains. The same type of test is extensively used in small grain im- 

 provement, not only in the preliminary testing of varieties, but also 

 in the comparison of strains and selections. Although the small plot 

 test is particularly subject to errors of certain sorts, it has a decided 

 advantage over tests in larger plots in the possibility of extensive 

 replication, which is probably the greatest single factor in the reduc- 

 tion of experimental error. It should be possible, consequently, to 

 obtain extremely accurate results in small plot tests without the use 

 of large experimental areas, when the errors peculiar to the small 

 plot are understood and controlled. 



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