FIELD PLOT TECH NIC 



63 



hamper a shorter one, or a vigorous grower may inhibit one that 

 grows more slowly. The existence of competition between ad- 

 jacent strains or varieties has been definitely proved at several 

 experiment stations. The work of Kiesselbach (1918) at the 

 Nebraska Station is particularly illuminating on this point. 

 Kiesselbach compared competition between adjacent single row 

 plots and adjacent plots each consisting of from three to five rows. 

 The yield of border rows was in some instances included in 

 the yield of the blocks. His results are summarized in Table. 

 XIV. 



TABLE XIV. SUMMARY OF RELATIVE GRAIN YIELDS OF VARIETIES TESTED 



IN SINGLE-ROW PLOTS AND ALSO IN BLOCKS CONTAINING 



SEVERAL Rows 



A comparison of the columns in Table XIV headed alternat- 

 ing rows and alternating blocks shows strikingly the effects of 

 competition. In almost every case the varieties grown in alter- 



