Florida Agricultural Experiment Stations


 The variables are evaluated from the standpoint of fruit pro-
duction, fruit quality and the mineral compositions of foliage and
fruit. As was pointed out earlier, the data have been classified
into groups and the mean of each group listed in tables. The
tables were used primarily to illustrate the trends observed.
Only those trends indicated by statistical analysis to be signifi-
cant will be treated in the discussion. It should be mentioned
also that information obtained from surveys should not be taken
as conclusive evidence, unless it can be substantiated by compari-
son with results of controlled experiments. However, there are
other observations for which no data from controlled experi-
ments are available at present for comparison. These findings
should merely be treated as trends observed in a large number of
Valencia orange groves. They may serve as guides for future
studies.
 INFLUENCE OF PLANTING DISTANCE
 The statistically significant relations (26) of tree spacing
to other variables were compiled in Table 13. The soluble solids
content of juice was also included to illustrate the source from
which the Brix/acid ratio is derived. The groves were classified
into groups based on the number of trees per acre and the aver-
age values of the characteristics measured were listed for each
group. Only seven groves were planted with between 75 and 84
trees per acre and fruit samples were obtained from six of them.
Because of the small number of groves used to make up the aver-
age values, some of the figures may not be entirely in line with
the trends observed. In order to compensate for some of the dif-
ferences found from one year to another, the averages over a
three-year period were used for fruit production when possible.
 There was very little difference in fruit production when the
data were expressed in boxes per tree in the range from 45 to 84
trees per acre. The yield per tree was approximately 30 percent
less in the group with 85 to 116 trees per acre. However, when
the data are expressed as boxes per acre, the increase in yield
is proportional to the number of trees planted on an acre up to
the 75 to 84 trees per acre range. Further increase in the num-
ber of trees per acre resulted in lower yield. The average pounds
of nitrogen applied to groves in each group was also included in
Table 13. These data indicated that nitrogen was applied at the
rate of approximately 200 pounds per acre in the majority of
the groves. Close to 300 pounds per acre of nitrogen were used