|Property of Water||Permitting this Use|
dissolves soil minerals, sugar, etc.|
widest range of any liquid!
cell: turgor pressure|
|high specific heat||
good heat buffer|
1 Calorie = 1 Liter 1° C
|high heat of fusion (vaporization)||
liquid→gas removes energy|
|precipitation: fog, mist, rain, snow, sleet, hail|
|runoff: brook, creek, stream, river|
|water table: puddle, pond, lake (Ocean is not freshwater)|
|soil water: capillary space...most useful for plants!|
|aquifers: porous rock, wells, artesian springs|
Mud ----> ______________ ----> ______________ ----> Absolutely Dry Soil
\ \ \
\ \ \
________________ ________________ ________________
water water water
The water that is available to plants is: ________________ water.
When this water is present the soil is called ________________.
Sprinkler: wastes water|
kills zygotes and larvae!
Surface: furrow = trenches with water between rows|
flood = one trench in un-level field
Trickle: Less wasteful at each pot|
Computer programming helps!
Wick: Capillary mat + ebb-flow pump|
plants take only as needed
Natural: 4 inches of rain per month|
irrigate only if short!
What time of day is best for irrigation? Early AM Noon PM Evening
How can you tell if your plant needs to be watered or not? (Hint: no green thumb needed)
|Touch surface of soil in pot with finger...|
if cold, wet, dirty: don't water now!|
if warm, dry, clean: water now.
|Symptioms of Overwatering|
Organs swell, crack open
Fungi thrive (Damp-off)
Yellowing of leaves
Root death by asphyxiation
|Symptioms of Underwatering|
Growth inhibition (dwarfing)
Leaves with brown tips + edges
Blueing of leaves
Abscission of leaves
One symptom is shared by both problems it is: _____________________
and this leads to many failures in home and landscape gardening.
|These symptoms are easily explained by Osmosis which is:|
Osmosis: The passive movement of water from purer area to more "polluted" area
|When a cell is placed in a hypotonic solution...|
Water moves into the cell
Cell gains weight
Cell gets larger
Cell develops turgor pressure
Stops when it cannot overcome wall pressure
|When a cell is placed in an isotonic solution...|
Water movement into the cell
...is balanced by water movement out of the cell
Cell has no weight change
Cell stays same size
Cell has no turgor pressure
But cell remains full
|When a cell is placed in a hypertonic solution...|
Water moves out of the cell
Cell loses weight change
Cell loses volume
Cell loses turgor pressure
Cell membrane pulls away from wall: plasmolysis
hypertonic solution fills space between cell membrane and cell wall
Stops losing water when concentration of cytosol matches solution
|When these conditions prevail the plant needs||more water||less water|
|It is a seedling||X|
|It is growing rapidly||X|
|It is reproducing (flowers and fruits)||X|
|It is dormant||X|
|It has succulent leaves||X|
|It has waxy leaves||X|
|It has hairy leaves||X|
|It has thin, fine, dissected leaves||X|
|It has deep roots||X|
|It is in a clay soil||X|
|It is in a sandy soil||X|
|The temperature is hot||X|
|The wind is blowing||X|
|The humidity is high||X|
|The sun is bright (no clouds)||X|
This page © Ross E. Koning 1994.
Go to the Course Schedule Page.
Go to the Plant Physiology Information Homepage.
Send comments and bug reports to Ross Koning at koningre∂gmail⋅com.