SPECIAL TECHNIQUES 



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f 12 



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10 



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in 

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Kernel width in mm. 



Kernel width in mm. 



Fig. 18. Pictorialized scatter diagrams for 4 samples of maize, all from 

 the town of Quezaltenango, Guatemala. Above: the same variety grown 

 in a manured and in an unmanured plot. Below: two very different varie- 

 ties grown in adjacent fields. In all four samples each of the 25 spots 

 represents 1 ear of maize, the shape of the spot representing the degree 

 to which the kernels are pointed, and the blackness indicating the rela- 

 tive amounts of hard and soft starch in the kernel. These four diagrams 

 demonstrate that superficial differences due to environmental effects are 

 scarcely apparent (note the similarity of manured and unmanured plots), 

 while fundamental differences are made conspicuous. Though there is 

 much variation in each, "Nueva Cuartel White" differs from "Nueva 

 Cuartel Yellow" in having on the average more pointed kernels, more 

 soft starch, higher row numbers, and narrower kernels. 



