Florida Agricultural Experiment Stations


was considerably less effective than heavy irrigation. On the
other hand, in areas where the rainfall deficit was small, as in
Orange and Lake counties, difference in fruit production between
the irrigated and non-irrigated groves was negligible. These
evidences point to the fact that irrigation facilities can be uti-
lized more beneficially when local weather conditions are taken
into consideration.
 No consistent difference was observed in fruit quality or min-
eral composition of leaf and fruit between the irrigated and non-
irrigated groves. Differences in fruit quality characteristics as
reported by Sites et al. (23) due to irrigation were found in only
a few very heavily irrigated groves, when compared to non-
irrigated groves in the same vicinity. Outright comparisons
between the irrigated and non-irrigated groves were of little
value because of the differences in quantity and distribution of
rainfall as well as supplemental irrigation in different areas.
 RELATION OF MINERAL COMPOSITION OF FRUIT AND LEAF
 TO FRUIT QUALITY
 Attempts were made to find out if any correlation existed
between leaf and fruit mineral composition and fruit quality.
Correlations between various fruit quality characteristics and
different mineral elements in leaf and fruit were tested. Pair-
ings which showed highly significant correlations (r) were used
to calculate linear regression coefficients (i). The results were
summarized in Table 24.
 In general, fruit quality is more closely associated with the
mineral composition of fruit than of the leaf. Data in Table 24
showed highly significant relation between certain characters
of fruit quality and the mineral contents of fruit, but not of leaf.
In other cases where fruit quality is related to both leaf and
fruit, the latter is more strongly correlated, as indicated by the
larger "r" values. It should be pointed out that some of the
correlations are rather weak even though statistically significant,
indicating that factors other than those measured have consid-
erable influence on fruit quality.
 Rind texture, which was expressed as percentage of fruit
smooth at stem-end, is the only external characteristic meas-
ured that was related appreciably to the mineral contents of leaf
and fruit. The percent smooth fruit varied directly with the
nitrogen and phosphorus contents of fruit, but inversely with
the magnesium content of both leaf and fruit. No consistent
trend was observed in the variation of fruit size and color that