Florida Agricultural Experiment Stations


 From the standpoint of internal fruit qualities, no consistent
trends were observed in the juice content, as affected by the
mineral composition of leaf and fruit. The soluble solids con-
tent, on the other hand, was inversely proportional to the phos-
phorus content of fruit and to a lesser degree that of the leaf.
The nitrogen content also affected the soluble solids of juice,
but the influence was not as strong as that of phosphorus. It
was pointed out earlier that no significant correlation was found
between the nitrogen content of fruit and the nitrogen applied in
the fertilizer, which seriously limited the practical application
of the data. The acid content of the juice was affected by the
phosphorus and magnesium contents of both leaf and fruit.
Juice with low acids generally was found associated with high
phosphorus and magnesium contents in both leaf and fruit.
 The Brix/acid ratio varied directly with the magnesium con-
tent of fruit and leaf and inversely with the potassium content
of fruit. The inverse relationship between the acid content of
juice and the magnesium contents of leaf and fruit resulted
in a higher ratio at higher ranges of magnesium content. The
soluble solids and acid content of the juice varied to some extent
with the potassium content of the fruit. Neither correlation
was highly significant when considered alone. The regression
observed for ratio is probably the accumulative effects of both
Brix and acid.
 The relation between vitamin C (ascorbic acid) content of
the juice and the mineral composition of leaf and fruit follows a
pattern similar to that of acid content. Vitamin C varied in-
versely with nitrogen, phosphorus and potassium contents of
fruit and also the phosphorus content of leaves.
 It was also found that both the soluble solids and acid con-
tents of the juice were very closely correlated to the percent dry
weight of the fruit.

 RELATION BETWEEN MINERAL COMPOSITIONS OF
 LEAF AND FRUIT
 In order to study the relation between the mineral composi-
tions of leaf and fruit, correlations were calculated for the ele-
ments under study. Leaf analysis was used as a basis for classifi-
cation in Table 25, to express the average values. Correlation co-
efficients were calculated on the entire 161 samples. Because of
the large number of groves involved, the degree of freedom at
which the "r" value would have been significant was also given to