FLORIDA STATE HORTICULTURAL SOCIETY 
101 
but are found in the soil in sufficient, 
though small quantities are sulphur, lime, 
magnesium, iron, etc. 
Ammonia is the element that produces 
growth. The spring and early summer is 
the best time to apply fertilizers having 
relatively high percentages of ammonia. 
It is best to wait for the removal of the 
fruit before applying high percentages of 
this element; yet I have seen growers ap¬ 
ply four and even six per cent of am¬ 
monia in February and then wonder why 
their late fruit became course and green 
before the time for shipment arrived. It 
would have been better to wait until after 
the fruit was picked before using stimu¬ 
lating applications of ammonia. 
Potash is necessary for the formation 
of sugars and wood and for the transfer 
of these compounds from one part of the 
tree to another. It is held that photosyn¬ 
thesis cannot take place without potash. 
It is commonly understood that potash 
produces a thin, tough peel, making a 
fruit better fitted to withstand the shocks 
of transportation. 
Soil Conditions. Let us turn back to 
the soil again. Four things are requisite 
for a satisfactory fertilizer program: (i) 
Proper type of land; (2) Water; (3) 
Humus; and (4) Soil bacteria. 
(O Type of Land. The trees should 
be planted on land adapted to citrus trees. 
The high pine lands of the Winter Haven 
section are a good example. These lands 
are high, well drained, and well aerated. 
The sub-soil is clay located deep enough 
to provide space for the tree roots and 
moisture is easy to retain. Groves have 
been set on flat woods and sand scrub 
lands in this section but the returns are 
not commensurate with the effort ex¬ 
pended. 
(2) Water. The citrus tree like all 
plants uses its food in solutions as dilute 
as the fraction of one per cent. The sap 
of the tree is very dilute, the only ap¬ 
proach to concentration being found in 
the fruit and seed. There is a constant 
stream of water flowing through the tree 
day and night. Large quantities of water 
are required for a tree to carry on its vi¬ 
tal functions. When the amount of wa¬ 
ter in the soil gets low, or in other words, 
when the solutions of food in the soil be¬ 
come too concentrated, the trees wilt. 
They are unable to get sufficient raw ma¬ 
terials for their requirements. 
( 3). Humns is decayed vegetable mat¬ 
ter thoroughly incorporated into the soil. 
Its presence in the soil makes it easier to 
retain moisture and encourages the 
growth of living agents. There are two 
ten-acre groves in our section that were 
planted side by side on the same kind of 
land seven years ago last winter. One 
grove man has kept his land virtually 
clean the year round. The other man has 
not. His grove is clean during the dry 
season and full of grasses and beggar- 
weed during the rainy season. Today 
the trees in the grove where clean culti¬ 
vation has been practiced the year round 
are fifty per cent smaller than those in 
the other grove. The amounts and qual¬ 
ity of fruit bear no comparison. The 
grove kept clean during the dry season 
only has produced three times as much 
fruit. 
(4). Soil Bacteria. Last but not least, 
are the soil bacteria. These are the agents 
that convert the crude materials of the soil 
