Hanna Instruments HI 83225 User Manual
Page 18
18
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