FIELD PLOT TECHNIC 



61 



size of plot is necessarily limited by available space and some- 

 times by amount of seed. Some form of row planting is usually 

 followed. These rows are planted, cultivated, and harvested 

 by hand and frequently show as low probable errors as those 

 obtained from J^o-acre field plots. 



r 



<o 4 



3 



1 1 . 1_ 



500250 125 



i- Size of Plot 



FIG. 13. Actual and theoretical reduction in standard deviation due to increase 



in size of plot. 



Shape of Plot and Border Effect. Often plants growing along 

 the side or end of the plot are more thrifty and vigorous than 

 those growing in the interior. When plots consist of single rows, 

 the plants at the extremities near the alleys or pathways appear 

 superior to those growing farther in. 



Mercer and Hall (1911) cut up a bulk field into plots of equal 

 area but different in shape (approximately 20 by 12 yd. and 50 by 

 5 yd.) and therefore without border effect. No significant differ- 

 ence in comparative variability was found between the two 

 shapes. Barber (1914) found that where cultivated pathways 

 surrounded plots, the plants along the margins were more pro- 

 ductive than those within the plot. 



Table XIII presents data collected by Arny and Hayes (1918). 

 The plots were seeded with a grain drill, the drill rows being 6 in. 

 apart. Eighteen-inch alleys separated the plots, and there was 

 a roadway along each end. In length the plots were trimmed 

 to 132 feet. In breadth they were 17 drill rows, each 6 inches 

 apart. Each of the two outside border rows was harvested sepa- 

 rately and the yield compared with the yields obtained from the 



