Composition of Florida-Grown Vegetables 25

 The protein content of tomatoes apparently did not correlate
with soil factors. Season may have been the cause of recorded
differences, inasmuch as the high protein tomatoes grown in
Collier County and in the Ft. Pierce area were harvested in
April and May, respectively, while the other 3 areas were har-
vested between November and February and contained less
protein.
 The magnesium content of tomatoes showed little variation,
even though there was considerable variation in exchangeable
magnesium in the soil. The calcareous soils contained much
more exchangeable potassium than the sandy soils, but only
in the case of marl soils was the potassium content of the to-
matoes high. The calcium content of tomatoes was higher when
grown on the calcareous soils than when grown on acid soils.
The iron content was lowest in tomatoes grown at Homestead
on Perrine marl. The Rockdale soils at Homestead contain a
high iron-bearing colloid of lateritic origin which evidently sup-
plies adequate available iron.
 There was no apparent correlation between soil and plant com-
position for collards grown in the Quincy area. The protein,
calcium and magnesium percentages in collards were higher than
in any of the other vegetables analyzed, yet the soils in which
the collards were grown were comparatively low in organic mat-
ter, calcium and magnesium. Collards grown under tobacco
shade on the fertilizer residue left from the tobacco crops and
those grown with fertilizer in open fields were similar in mineral
composition.
 The primary interrelationship that characterized soil types
appeared to be between organic matter content and pH of the
soil, with other factors of soil, environment and moderate differ-
ences in fertilization of secondary importance.

 Summary
 Samples of marketable vegetables and of the soils in which
they were grown were collected from commercial fields through-
out the State of Florida and analyzed for mineral composition.
Data are discussed with respect to variation from the general
averages so obtained for the state.
 The mineral content of a given vegetable varied as much as
200 percent when grown on different soils in different areas.
There was also considerable variation even within areas of simi-
lar soils. Therefore, it is impractical to report a specific figure