Feb.4,i9i8 Variability of Yields of Fruit Trees and Field Trials 261 



The averages of all six fruit plantations show that there is a rapid 

 reduction of the coefficient of variability until the 8-tree plot is reached, 

 but from then on the reduction is less in comparison with the probable 

 error. (See Table III, summary, and figure 8.) 



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Fjg. 7. — Graphs of the reduction of the coefficient of variability by increasing the number of adjacent trees 



to the plot. 



Although the average reduction of the coefficient between the 8-and 

 i6-tree plots is doubtful when compared with the probable error, this 

 reduction in all six cases is constant — that is, the variation occurs in 



