NOTE ON THE INELUEN.CE OE S'H'A'PE AND SIZE OE 

 PLOTS IN TESTS OE VARIETIES OF GRAI'N.* 



By CivARENCK W. Barber. 



Experience in testing varieties of oats in rows under culti- 

 vation, in small and large plots, and' under field conditions, 

 impresses one with the widely variable results obtained in the 

 propagation of oats in different allowances of space for devel- 

 opment. In variety tests it is customary to surround each plot 

 with a pathway which is generally keipt clear of weed§ and other 

 plants by cultivation. This passageway aiot only permits close 

 observation of the plants within the plot but also prevents the 

 mixture of varieties at the time of planting and at harvest. 

 Observation of oats grown in plots thus separated often presents 

 a marked contrast in respect to the productivity of plants situ- 

 ated along the borders of the plots as compared with plants 

 growing within the plot. Tliis thriftiness of marginal plants 

 is exemplified in a greater number of culms per plant, a higher 

 yield of grain, and a longer period of growth. Generally the 

 marginal plants thrive in a green condition several days after 

 the plants in the center of the plot 'have begun to ripen. As an 

 illustration of the cropping ability of a strain of oats under 

 different conditions may be cited the performance of a Line 

 No. 286 of oats originated by the Maine Agricultural Experi- 

 ment Station. In a plant breeding garden where one s'eed was 

 dropped at each three inch interval in drills one foot apart, this 

 line of oats yielded at the rate of 11.3 grams of grain per plant. 

 In two two-thousandth acre plots for this same line the average 

 production of grain per plant amounted to 2.94 grams. In the 

 latter case seed was planted at intervals of one and one-half 

 inches in drills four inches apart. In the first instance each 

 plant was allotted thirty-six square inches ; in the second in- 

 stance six square inches. The yield per plant in the larger space 

 was nearly four times that of plants grown in the smaller space. 



* Papers from the Biological Laboratory of the Maine Agricultural 

 Experiment Station No. 62. 



