Hanna Instruments HI 83215-2008 Series User Manual
Page 17
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POTASSIUM
Potassium (K) is essential in proteic synthesis. The problem of lack of potassium is quite frequent in
calcareous soils.
Potassium is absorbed as K
+
.
PRESENT IN
tissues responsible for the growth of plants (primary and secondary meristems), embryos and cell
vacuole
ACTION
• improves the quality of fruits and flowers
• gives more resistance both to frost and to diseases caused by fungi (increases the cuticular thickness)
• regulates the cellular turgidity (helps to regulate the osmotic processes and increases the
resistance to dryness)
• regulates the stomatic opening and closing (it means a strong influence on transpiration and
photosynthesis)
SHORTAGE
• slower growth
EFFECTS
• smaller fruits, less colored and less preserved
• increase of transpiration
• less resistance to the cold
PHOSPHORUS
Phosphorus (P) has an important role in many fundamental biochemical and physiological processes. Plants
take up phosphorus in the form of phosphate ion (PO
4
3
¯).
PRESENT IN
DNA and RNA, ATP, ADP
ACTION
• stimulates the roots growth
• stimulates blooming
• stimulates fecundation and ripeness
• strengthens the plant tissues
• is necessary in the formation of seeds
SHORTAGE
• delayed ripening
EFFECTS
• slower growth
• small leaves
• decrease of production (smaller fruits and difficult seeds formation)
• reduction of root system
EXCESS EFFECTS
• premature ripening
• excess of fruit-setting
• negative effects on the absorption of some microelements such as iron, zinc, boron and copper
EXCESS EFFECTS
• reduced absorption of calcium and magnesium
• increase of water consumption
• increase of the substrate salinity