Nutrient
deficiencies of Angelonia
By Amy Williams, Brian E. Whipker, Paul V. Nelson, John M. Dole, Brenda
R. Cleveland and F.R. Walls
Fertility monitoring and management for angelonia requires a balancing
of the plant’s needs. Growers must be aware and manage the root
substrate pH, electrical conductivity (EC) and provide adequate, but not
excessive, levels of all essential elements.
Nutrient deficiency descriptions are unavailable for most floriculture
crops, yet growers must often make quick diagnoses. A research project
initiated at North Carolina State University in Raleigh documented deficiency
symptoms in Angelonia angustifolia ‘Carita Purple’, to assist
growers. Using a plant diagnostic lab to identify the source of problems
is still the best way to ensure accurate diagnoses, since many nutritional,
physiological, insect and disease problems can mimic each other.
Disclainer: Growers should read and follow all label
directions. Test the corrective procedure on a small number of plants
prior to applying it to the entire crop.
Macronutrients ·
Micronutrients
|
Macronutrients
| Photograph |
|
Possible Causes and Management |
| Nitrogen (N) (top) |
|
Nitrogen deficiency develops as overall
smaller plants with less axillary branching.
|
Low Substrate
Nitrogen |
 |
Nitrogen-deficient shoots are about two-thirds the
length of the control shoots. |
 |
As symptoms progress, shoot length remains stunted
and develops a stiff upright stem. |
 |
Advanced symptoms are noticeable when the lowest most mature
leaves develop a yellow-green basal chlorosis, which progresses
to a reddish-brown necrotic withering. |
| Phosphorus (P) (top) |
 |
Initially, phosphorus-deficient leaves
develop a faint dark green cast. |
Low Substrate
Phosphorus |
 |
With advanced symptoms, there is little to no axillary
branching on the stunted shoots and the phosphorus-deficient plants
develop a dull green cast compared to the control. |
| Potassium (K) (top) |
 |
Initially, potassium deficiency appears
on the mature leaf tips as a light green chlorosis, which quickly
turns brown.
|
Low Substrate
Potassium |
 |
As symptoms progress, the mature chlorotic leaf tips
develop brown to black necrotic patches on the margins. |
 |
Advanced symptoms show complete necrosis of the lower
mature leaves. Eventually the necrotic regions curl and develop a
withered papery texture. |
| Calcium (Ca) (top) |
 |
Initially, calcium-deficient plants develop small
brown necrotic spots on the margins of the young chlorotic leaves.
|
Low Substrate
Calcium |
 |
Calcium deficient plants are small and compact compared
to the control. |
 |
As symptoms progress, a light yellow-green marginal
chlorosis develops on the young and recently mature leaves. These
leaves begin to curve and pucker which causes them to look deformed. |
 |
At advanced stages, the young to recently mature
leaves begin to curl downward. The young leaf tips develop a brown
necrosis, while the flower buds turn brown and abort. |
| Magnesium (Mg) (top) |
 |
Magnesium deficiency initially appears
on the mature leaf margins as a light green interveinal chlorosis.
|
Low Substrate
Magnesium |
 |
The mature leaves quickly develop tan to brown necrotic
patches, which originated at the chlorotic margins. |
 |
Close-up of a advanced mature leaf with tan marginal
necrosis. |
| Sulfur (S) (top) |
 |
Sulfur deficiency initially appears as small severely
stunted plants with little to no axillary branching.
|
Low Substrate
Sulfur |
 |
As symptoms progress, the internodes remain short
and develop a pink to purple pigmentation near the shoot tip. |
 |
Sulfur-deficient plants are short, compact and rigid at advanced
stages. |
 |
Shoots are extremely stunted and lack axillary branches.
The young to mature leaves are short and narrow compared to the
control. Overall the plants develop a faint lime-green cast. |
Micronutrients (top)
| Photograph |
|
Possible Causes and Management |
| Boron (B) (top)
|
 |
Initially, boron deficiency affects
the young leaves, which are often twisted and deformed. A light
green marginal chlorosis develops on the young to recently mature
leaves, while the entire plant becomes glossy.
|
Low Substrate
Boron |
 |
As symptoms progress, the young to mature leaves
become slightly shorter, wider and glossier than the control, with
a bleach-white basal chlorosis. |
 |
The chlorotic shoot tip develops a rosette appearance
because it has stopped elongating. Small-deformed buds turn brown
and abort. |
| Copper (Cu) (top)
|
 |
Copper-deficiency first appears with a curling of the young leaves
in a spiral manner. |
Low Substrate
Copper |
 |
The young to recently mature leaves develop a severe downward curling
with recessed midveins.
|
 |
As symptoms progress, the mature leaves develop a
tan to brown necrosis on the margins. |
 |
The mature leaves become more necrotic
and begin to curl at the leaf tips. Overall the leaves develop a
dull blue-green cast, compared to the control. |
 |
The copper-deficient flowers develop a dramatic pink
pigmentation, compared to the purple control. |
| Iron (Fe) (top)
|
 |
Initially, on iron-deficient plants the young leaves
develop a light green chlorosis and the recently mature leaves show
a faint interveinal chlorosis.
|
Low Substrate
Iron |
 |
As symptoms progress, the young axillary
shoots develop a light whitish-green chlorosis. |
 |
Advanced iron deficiency shows the recently mature
to upper-mature leaves with a distinct light green interveinal chlorosis.
A uniform light yellow-green chlorosis appears on the young leaves. |
| Manganese (Mn) (top)
|
 |
Initially, manganese deficient plants
are often small and develop a uniform light green chlorosis, while
the recently mature leaves develop a marginal chlorosis.
|
Low Substrate
Manganese |
 |
As symptoms progress, the shoots fail
to elongate and there is little to no axillary branching. The shoots
develop a dull light green chlorosis and recently mature leaves
appear slightly smaller than the control. |
 |
Severely stunted chlorotic plants with
thick canopies are advanced symptoms of manganese deficiency. |
| Zinc (Zn) (top)
|
 |
The initial symptom of zinc deficiency is
a tan necrosis on the mature leaf tips, which then begin to curl.
|
Low Substrate
Zinc |
 |
Symptoms progress to a severe necrosis of the leaf tips which advances
to the middle of the leaves. |
 |
This close-up shows the withered curling leaf tips of the mature
leaves. These necrotic leaves become papery and eventually begin to
collapse. |
Amy L. Williams is a graduate research assistant, Paul
V. Nelson is professor in floriculture, John Dole is associate professor
in floriculture, and Brian E. Whipker is assistant professor in floriculture
at North Carolina State University, Department of Horticultural Science,
Box 7609, Raleigh, NC 27695-7609.Brenda R. Cleveland is agronomist and
F.R. Walls is assistant director, Agronomic Division of North Carolina
Department of Agriculture, 4300 Reedy Creek Road Raleigh, NC 27607-6465.
We would like to thank Paul
Ecke Ranch, Encinitas, CA., Tom Abramowski, Rockwell
Farms, Rockwell, N.C., and the North
Carolina Commercial Flower Growers' for grant support, Paul Ecke Ranch
for supplying the cuttings and Smithers-Oasis
for supplying the propagation medium.
Disclainer: Growers should read and follow
all label directions. Test the corrective procedure on a small number
of plants prior to applying it to the entire crop.
© Copyright NC State University, 2003
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