Transcript Floriculture Disorders - Talbot County School District

Nursery/ Landscape
Disorders
Eddie McKie
APHIDS
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
Small (up to ¼”) softbodied insects.
The characteristic
feature that
distinguishes aphids
from other insects are
the “tail pipes” (called
cornicles) which
extend from the rear
of their abdomen.
Bagworm

Any of several moths of
the family Psychidae,
which construct fibrous
cases of silk spun
together with leaves,
twigs, or grass. The plantfeeding larvae and
wingless adult females
live in these cases.
Borer

Type of caterpillar
that goes inside the
plant (usually
between cambium
and bark or inside the
pith of some stems)
and feeds. Can and
often does cause
death of plant.
Grub

Thick, soft insect
larvae (usually a
beetle larvae)
LEAF MINER

Insect larvae that feed
inside a leaf, between
the upper and lower
surfaces.
MEALY BUG

Mealybugs derive
their name from the
white, waxy, mealy
secretions that cover
their bodies.
POWDERY MILDEW
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Infected plants will
display white powderlike spots on the
leaves and stems.
The fungus is favored
by periods of high
relative humidity or
site conditions that
promote a more
humid environment
SCALE
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Either soft scales or
armored scales
Covered with waxy
shell for most of their
life which protects
them from predators
or insecticides
SLUG

Slugs are gastropod
mollusks without
shells or with very
small internal shells,
in contrast to snails.
SPIDER MITE


To the naked eye,
spider mites look like
tiny moving dots
Adults have eight legs
and an oval body,
with two red eyespots
near the head end of
the body.
WHITEFLY


Adults are less than
1/8” long and, like
their name suggests,
have white wings with
pale yellow bodies.
Adult whiteflies
congregate above
and under leaf
surfaces, and
disperse in clouds
when disturbed.
BLACK SPOT
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Round to irregular black splotches
with fringed margins are quite
obvious, mostly on upper leaf
surfaces.
Round to irregular black splotches
with fringed margins are quite
obvious, mostly on upper leaf
surfaces. Leaf yellowing develops
around these black spots, with
defoliation of these infected leaves
common. Round to irregular black
splotches with fringed margins are
quite obvious, mostly on upper
leaf surfaces. Leaf yellowing
develops around these black
spots, with defoliation of these
infected leaves common. Leaf
yellowing develops around these
black spots, with defoliation of
these infected leaves common.
IRON CHLOROSIS


Iron chlorosis is a
yellowing of plant leaves
caused by iron deficiency
that affects many
desirable landscape.
The primary symptom of
iron deficiency is
interveinal chlorosis, the
development of a yellow
leaf with a network of
dark green veins.
Annual Bluegrass

One of the most
common weeds of
turf, ornamental
plantings, and
gardens in the United
States. It has a boatshaped tip, folded in
the bud.
Plantain

Species of familiar
garden, lawn, and
roadside weeds. The
leaves lack a proper
blade. What appears to
be a blade is an
expanded petiole with
several parallel main
veins, emerging at the
base of the stalk. Small
flowers are borne in
spikes or heads atop long
leafless stalks
NUTGRASS



Nutgrass has yellowgreen, wide-bladed
leaves that are
smooth and shiny or
waxy on the upper
side.
Nutgrass grows 1-3
feet tall if not mowed.
Yellow and purple
varieties
Chickweed

Either of two species of
small-leaved weeds.
Common chickweed
usually grows to 18 in.
but is a low-growing and
spreading annual weed in
mowed lawns. Mouse-ear
chickweed is usually a
shorter, mat-forming,
spreading perennial with
many upright stems. Both
species have
inconspicuous but
delicate white, starshaped flowers.
CRABGRASS
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Crabgras is a low-growing
summer annual that spreads
by seed and from rootings of
nodes that lie on the soil.
It may grow upright to a height
of 2 feet. It will not tolerate
close mowing as well as
smooth crabgrass.
True leaves are generally 3
inches long and hairy on the
upper surface of the leaf and
leaf sheath.
The branches are l about 2 to
5 inches at the end of the stalk.
Dandelion

Weedy perennial
herbaceous plant that is
widespread in much of
temperate North America.
Has a rosette of leaves at
the base of the plant; a
deep taproot; a smooth,
hollow stem; and a
solitary yellow flower
head composed only of
ray flowers (no disk
flowers). The fruit is a
ball-shaped cluster of
many small, tufted, oneseeded fruits.
Henbit

Lower leaves have a stalk
while the upper leaves
clasp the stem. Stems
are square. Leaves are
coarsely toothed and
opposite from each other.
Flowers appear in May
and are about one-half
inch long, trumpetshaped, pinkish white to
purple, and form just
above upper leaves.
OXALIS

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The leaves are divided
into three to ten or more
round, heart-shaped or
lanceolate leaflets,
arranged in a whorl with
all the leaflets of roughly
equal size.
The majority of species
have three leaflets; in
these species, the leaves
are superficially similar to
those of some clovers
Clover

Creeps to form patches in
turf and emerges from a
fibrous root system.
Compound leaves are
composed of three
unstalked oval leaflets, up to
4/5 inch long. They are dark
green and often with faint,
white, crescent-shaped
markings. Clover flowers
occur in ball-shaped white to
pink clusters of pea-shaped
flowers that are held slightly
above the foliage. This weed
occurs in most lawns and
especially in moist, lowfertility soils throughout
growing season.
Purslane

Common purslane is an
annual broadleaf that grows
rapidly in spring and summer.
Leaves are very succulent,
often tinged red, and wedgeshaped. Small yellow flowers
are born singly or in clusters of
two or three in stem junctions
or at tips of stems. The mature
plant may form a mat or grow
up to a foot tall. The plant
branches at the base and
along the stems. Purslane
seeds are very tiny and
produced in abundance.
Wild Garlic/Onion

Wild Onion Characteristics:

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Bulb has reticulated (net like)
membrane or covering.
Leaves occur from the base of
the plant, and tend to be flat
(not hollow).
Wild Garlic Characteristics:


Leaves are hollow, and tend to
be formed higher on the stem
(not where stem comes out of
the ground).
Distinct garlic odor.