102 



T. Lyttleton Lyon and James A. Bizzell 



larger yields of the primary crops when grown in mixtures than when 

 grown alone is perhaps deserving of attention, especially since in the squares 

 containing mixtures seventy-five plants were grown in six inches of soil 

 eighteen inches square, and consequently there must have been more com- 

 petition for food in the mixtures than in the pure cultures. 



The cultures in ground quartz emphasize this more strongly, as may be 

 seen in Table 42: 



TABLE 42. 



Relative Yields of Primary Crops Grown Alone and of Primary Crops 

 IN Mixtures in Nutrient Solution in Crushed Quartz 



Primary crop 



Secondary crop 



Yield of 

 primary crop 



grown in 



mixture when 



primary crop 



alone is taken 



as 100 



Yield of 



secondary 



crop when 



primary crop 



in mixture is 



taken as 100 



Period of 



growth of 



plants 



(days) 



Wheat. . . 

 Wheat. . . . 

 Wheat. . . . 

 Wheat. . . 



Oats 



Oats 



Oats 



Peas 



Peas 



Peas 



Peas 



Timothy. . 

 Timothy. . 

 Timothy. . 

 Timothy. . 

 Timothy. . 

 Timothy. . 

 Timothy.. 

 Timothy. . 

 Red clover 

 Red clover 

 Timothy . . 

 Timothy. . 

 Wheat. . . . 

 Wheat. . . . 

 Wheat.... 

 Wheat. . . . 

 Wheat.... 



Wheat 



Oats 



Oats 



Mustard. . 

 Mustard . . 

 Mustard. . 

 Mustard. . 

 Mustard. . 

 Mustard. . 

 Mustard. . 

 Lettuce. . . 

 Lettuce. . . 

 Lettuce. . . 

 Lettuce. . . 

 Blue grass . 

 Blue grass . 

 Blue grass . 

 Blue grass . 

 Red clover 

 Red clover 

 Red clover 

 Red clover 

 Timothy. . 

 Timothy. . 



Daisy 



Daisy 



Red clover 

 Red clover 

 Red clover, 

 Red clover. 

 Timothy . . 

 Timothy. . 

 Timothv. . 

 Timothy . . 



132 



126 



106 



108 



133 



96 



98 



87 



76 



86 



91 



95 



78 



84 



73 



152 



116 



76 



81 



123 



109 



107 



124 



95 



105 



96 



109 



100 



111 



102 



75 



34 

 20 



89 



100 



19 



73 



99 



15 



8 



8 



3 



50 



72 



19 



26 



38 



44 



180 



146 



26 



44 



36 



47 



20 



27 



4 



5 



5 



7 



6 



11 



87 

 87 

 51 

 51 

 87 

 48 

 48 

 83 

 83 

 54 

 54 

 94 

 94 

 67 

 67 

 94 

 94 

 67 

 67 

 94 

 94 

 93 

 93 

 71 

 71 

 60 

 60 

 59 

 59 

 59 

 59 



