EXPERIMENTS IN FIELD PLOT TECHNIC 



59 



ing plots. For example if the yield of a check plot is reduced 20 per 

 cent by a poor stand, the adjusted yields of neighboring plots will be 

 increased to the same extent as if the check plot yield had been low be- 

 cause of poor soil, and will consequently be considerably higher than 

 they should be. It is important therefore that conditions be made as fa- 

 vorable as possible for accurate yield testing when this method is used. 

 One cause for poor results in the adjustment of yield in some of the 

 experiments reported in this paper was failure to protect the outside 

 strip of check plots by means of border rows, in a few of the tests, be- 



TABLE 31. RELATIVE VARIABILITY OF ACTUAL AND ADJUSTED YIELDS. 

 Average Deviation in Percentage of Yield. Barley Variety Test 1919. 



Average deviation 



Planting Actual yields Adjusted yields 



number Variety 3 interior rows 5 rows 3 interior rows 5 rows 



