GCO 1402 Part 2
Turfgrass Science
Magnesium
• Leachable
Mobile
• Absorbed as Mg+2
• Critical levels
–woodies 0.3 - 0.5%
–herbaceous 0.5 - 0.8%
–warm season 0.05 - 0.1%
Physiological Roles of
magnesium
• 1. chelated in chlorophyl
molecule
• 2. role in formation of cell plate
in mitosis
• 3. phosphate transport
(transport of phospholipids)
• 4. enzyme activator
Magnesium
deficiency symptoms
• Turf (cool season)
– older leaves are
chlorotic - blotches, cherry
red
• Turf (warm season)
–1. older leaves are pale green
to yellow
Conditions conducive to
magnesium deficiency
•
•
•
•
•
•
Sandy soils
Heavy rainfall or irrigation
High calcium to magnesium ratio
Acidic conditions
Seed set
Heavy K fertilization
Healthy Canary island date
palm
Canary island date palm with
symptoms of magnesium
deficiency
• Note the yellowing in the older fronds
progressing from tip to base of the
leaflets
Another magnesium
deficient date palm
Podocarpus nagi suffering
from magnesium deficiency
• Magnesium exhibits the widest range of
deficiency symptoms. In this species
the symptoms appear as a yellow stripe
across the center of the older leaves
Calcium
• not leachable
not mobile
• absorbed as Ca+2
• Critical levels:
•
woodies
0.6 - 1.0%
•
herbaceous 0.2 - 0.4%
•
warm season 0.02 - 0.1%
Physiological Roles
• 1. detoxicant in cell - detoxifies
microelement, organic acids
• 2. Calcium Pectate (middle
lemmela) in cell walls
• 3. buffers stigmatic fluids and
maintains pH so that pollenation
can take place
• 4. involved in cell plate formation
Calcium
Deficiency Symptoms
• 1. new leaves curl
• 2. terminal bud dies
• 3. normal older leaves
• * Note: Ca dificient symptoms
rarely occur
Main uses of calcium
• as a liming material
• managing sodium affected
soils
Liming
more highly weathered
soils
• Corn
pH % Al Saturation
4.4
5.6
68
27
% Rel yield
18
100
Liming
more highly weathered
soils
• cotton
pH
% Al Saturation
4.6
5.7
6.0
67
19
7
% Rel yield
25
99
100
Liming
more highly weathered
soils
• soybeans
pH % Al Saturation
4.9
5.4
44
20
% Rel yield
31
100
Calcium ions and Al
toxicity
• Root length in mm
Al conc
Ca 10ppm
0
376
0.5
295
1.0
59
2.0
40
Ca 40ppm
445
443
427
245
Sulfur
• Leachable
non-mobile
• Absorbed in the elemental (S) form
• Critical levels 0.4 - 1%
• woodies and herbaceous
Physiological Roles
• 1. constituent of amino acids
• 2. part of chlorophyll
Sulfur deficiency symptoms
• General chlorosis in the new
leaves first
• growth reduction not as
dramatic as with nitrogen
Mahonia with sulfur deficiency
• Sulfur deficiency appears as a general
chlorosis of the older leaves first
Sulfur deficiency in
east Palatka holly
Chlorosis of new leaves first
Conditions Conducive to
an Sulfur Deficiency
• 1. heavy rainfall
• 2. sandy soils with low organic
material
• 3. legumes more susceptible
Iron
• not mobile
not leachable
• Absorbed as Fe+2 and Fe+3
• critical nutrient level
60 - 120 ppm
Physiological Roles
• 1. chlorophyll synthesis used in the
precursor molecule in the formation of
chlorophyll
• 2. enzyme activator in respiration
Fe Deficiency Symptom
• 1. interveinal chlorosis of new
leaves
• 2. smaller leaves, yellow to creamy
white
Conditions Conducive to Fe
Deficiency
•
•
•
•
•
•
1.
2.
3.
4.
5.
6.
alkaline soils
high amount of organic material
high amounts of phosphates
excessive thatch
water logged or compacted soils
any causes of limited rooting
Foliar applications - Salts
Ferrous Sulfate
Ferrous Ammonium Sulfate
Soil Applications - Chelates
expensive but can be used both
foliar and washed into the root
zone
Iron deficiency in bahiagrass
• This area has a couple of problems,
compaction due to car traffic, and is
primarily lime rock used for parking.
The combination of low oxygen and
high pH in the root zone is ideal for
creating iron deficiency.
More iron deficiency of
bahiagrass
• These trees were new
plantings being irrigated
with microjet irrigation and
high pH well water. The
pattern of irrigation is
clearly defined by the iron
deficiency.
Close up of iron deficiency on
bahiagrass
• Note the chlorosis is in the newer
leaves. Interveinal chlorosis can be
difficult to see on grass leaves because
of their size and parallel venation,
however close inspection will usually
show traces of this pattern.
Iron deficiency
• This is “textbook” iron deficiency.
Interveinal chlorosis of the new leaves
first. The veins are very distinctly green
and clearly defined. The color is
“creamy” white and there is some leaf
size reduction.
Manganese
• not leachable not mobile
• absorbed as MnO & MnO2
• Critical Nutrient Levels
–50 - 100 ppm
Manganese
• Physiological Roles
–chlorophyll synthesis
–involved in photosynthesis
Deficiency symptoms
• same as iron, no leaf size reduction
• band of green tissue, seldom
passes yellow/green
Manganese deficiency
• Manganese deficiency is similar to iron
deficiency. However there is typically a
band of tissue next to the veins that
remains green, generally no leaf size
reduction, and the color seldom lightens
beyond yellow green.
Manganese Deficiency in
Queen Palms
• Manganese deficiency in queen
palms produces a very
distinctive look called frizzel top
• Applications of manganese to
the bud and foliage should be
included in any curative or
preventative application.
Healthy queen palms
Early stages of frizzle top
Severe frizzle top
Conditions Conducive to Mn
deficiency
• 1. high pH - alkaline soils
• 2. High P quantities
• 3. Some plants more prone
– queen palms
– dogwoods
• 4. Not uncommon on putting
greens
Zinc
• not leachable not mobile
• absorbed as Zn+2
• Critical Nutrient Levels
• 20 - 50 ppm
• Physiological Roles
– involved in the synthesis of
indoleacetic acid IAA
Deficiencies Symptoms
• 1. internodes between leaves
do not elongate
• 2. causes rosetting
• 3. wrinkled twisted leaves
Zinc deficiency
• This picture shows “little leaf” of
peaches and is characteristic of the
growth deformities associated with zinc
deficiency.
Copper
• not leachable not mobile
• absorbed as Cu+2
• Critical Nutrient Level
–5 - 15 ppm
–can be toxic
Copper
• Physiological Role:
•
1. enzyme activator
• Deficiency Symptom
•
1. withces broom
Boron
• leachable, not mobile
• Critical Nutrient Level 15 - 30 ppm
• Physiological Roles:
– involved in sugar transport
Boron
• Deficiency
Symptoms:
• small raised corky
spots along main vein
on underside of leaf
• may or may not have
chlorosis
• looses geotrophic
responses
Molybdenum
• not leachable, not mobile
• Critical Root Requirements less
than 1 ppm
• Physiological Roles:
– involved in nitrate reduction
Molybdenum
• Deficiency Symptoms:
• leaf has veins extended beyond leaf
margin
• long strap-like leaf
• * More available at high pH
• Hibiscus, Dogwoods, and Crepe
Myrtles have problems with
Molybdenum
Chlorine & Nickel
• Deficiencies don’t occur in any natural
setting
• not an issue in any fertility program
Just when you think you’ve
seen it all
• This picture shows the effect of
lightning striking the ground in a fine
turfgrass. Mother nature loves to throw
golf course superintendents “curve
balls”.