FLORIDA STATE HORTICULTURAL SOCIETY. 
12S 
appreciable growth and when there is an 
insufficient supply of this element the 
plant's foliage does not develop a rich 
green color but takes on a yellowish 
tinge. 
Phosphorus occurs in parts of the 
plant in the form, of phosphates. These 
phosphates play a very important part in 
the development of the young plant at 
the time of germination. 
Phosphoric acid is one of the constitu¬ 
ents of chlorophyll and is necessary ft li¬ 
the building up of every plant cell. It is 
not only important to young plants but is 
necessary at all stages of the plant’s 
growth. 
The chief function of phosphorus 
may be said to be to aid in the production 
and transportation of the proteid sub¬ 
stances. These proteid bodies which are 
produced in the leaves are finally trans¬ 
ported to the seed where they accumulate 
to the greatest extent. From 60 to 75 per 
cent, of the total phosphates removed in 
a crop is found in the seeds. 
The translocation of phosphoric acid 
in the plant is very interesting. It is the 
most mobile substance of all the inorgan¬ 
ic constituents of plants. It is continually 
moving from the lower to the upper part 
of plants, and a large percentage of phos¬ 
phoric acid found in the grain was moved 
from the leaves and stems of plants even 
after it had once come to a rest in these 
organs. 
In speaking of the function of potassi¬ 
um Prof. Harry Snyder in his excellent 
work on “The Chemistry of Plant and 
Animal Life” says: “Potassium is one of 
the most important and least variable of 
all the elements found in the ash of 
plants. It is quite evenly distributed 
throughout the growing plant and gener¬ 
ally occurs in the entire plant in the larg¬ 
est proportion of any of the essential ash 
elements. It is taken up in the early 
stages of plant growth and is always 
present to the greatest extent in the 
active and growing parts as in the 
leaves where the production of plant tis¬ 
sue occurs. Potassium is one of the ele¬ 
ments most essential for the plant’s de¬ 
velopment. 
“The function of potassium is appar¬ 
ently to aid in the production and trans¬ 
portation of the carbohydrate com¬ 
pounds, as starch and sugar, and thus in¬ 
directly in the formation of all organic 
matter. In sugar and starch-producing 
crops, as sugar beets and potatoes, it 
takes an important part in the growth and 
development. Potassium doubtless has 
much to do in the way of regulating the 
acidity of the sap by forming organic 
salts such as potassium bitartrate in 
grapes. At the time of seed formation 
there is a slight retrograde movement of 
the potash, in some cases a small part be¬ 
ing returned to the soil. The supply of 
available potash in the soil has great in¬ 
fluence upon the vigor of plant growth. 
Weak and sickly plants are always defi¬ 
cient in potash. Some crops require more 
growth than do others and some experi¬ 
ence difficulty in obtaining it. Some 
plants contain such large amounts of pot¬ 
ash that they are called ‘potash plants/ ” 
All research shows that in the higher 
order of plants potassium; cannot be re¬ 
placed or substituted by any other ele¬ 
ment 
It is a common fact to all plants that 
the various constituents move about in 
the plant during its growth. 
