Transcript Plant-Disorders - Mid

Plant Disorders
Nursery/Landscape
INSECTS
Aphid
•
Aphids on a Corn leave
Aphids are small (about 1/8 of and inch long), soft-bodied,
pear-shaped insects of many colors such as green, black,
gray, yellow or red.
Bag Worm
Borer
These Borers have been found in the stems of
Strawberry leaves and the much larger main
stems of Hollyhock and various other Plants and
weeds.
The Larvae appear to be identical and thrash
their front ends around violently when
disturbed.
Some Borers attack roots, some attack stems,
some bore through the bark of trees where they
may girdle the
Leafhopper
Scale
Spider Mites
A heavy spider mite infestation (Acari) caused the curling, distortion, yellow patches and
bronzed patches on the leaves of this tomato plant (Lycopersicon)
Snails/SLUGS
• Slugs can destroy foliage faster than plants can grow. They also feed on fruits and
vegetables prior to harvest, making holes in the crops. Slugs bodies are mostly water
and the soft tissue of their bodies are tender and prone to dry out.
Tent Caterpillar
Whitefly
Whitefly is a primary insect pest of many fruit, vegetable and ornamental crops,
frequently being found in
Adults are 1-2 mm in length, with yellowish bodies and four wax-coated wings held
near parallel to the leaf surface.
White Grub
White grubs can devastate your lawn. White grubs (European chafer, May and June
Beetles) are small plump white larvae which actively feed on grass roots. They live
below the soil surface and actually chew off the roots of the grass plants. They are C
shaped, have a brown head and have 3 large pairs of legs.
DISEASES
Anthracnose
•
Anthracnose (Discula spp., Kabatiella
apocrypta) is a name for a group of diseases
caused by several closely related fungi that
attack many of our finest shade trees. It
occurs most commonly and severely on
sycamore, white oak, elm, dogwood, and
maple.
Apple Scab
•
The scab-like leaf spots and fruit spots, from
which the name was developed, may cause
defoliation and reduction in fruit quantity and
quality.
Black Spot
Leaf symptoms are roundish, black spots with fringed margins that can be up to ½"
in diameter. The spots form on the upper sides of leaves.
The tissue surrounding the spots turns yellow. Infected leaves may prematurely drop
from the plant. Usually lower leaves are infected first. Excessive leaf drop weakens the
plant, predisposing it to other forms of injury such as those caused by temperature
extremes.
Botrytis
Botrytis blight or gray mold is a fungus disease which infects a wide array of
herbaceous annual and perennial plants.
Cedar apple rust
•
During warm rainy days in late April and early May, cedar trees infected with the
cedar-apple rust fungus will develop bright orange, gelatinous galls.
Crown Gall
Crown gall, a disease of roots and stems, occurs on a
large number of plants.
Fireblight
Powdery Mildew
WEEDS
Annual Bluegrass
Broadleaf Plantain
Buckhorn Plantain
Bull Thistle
Chickweed
Crabgrass
Dandelion
Field Bindweed
Henbit
Knotweed
Nimblewill
Nutsedge
Oxalis
Prickly Lettuce
Purslane
White Clover
PHYSIOLOGICAL PROBLEMS
Iron Deficiency
Symptoms:
Iron-deficient plants are yellow and stunted, with the symptoms expressed on the
young leaves first. Affected leaves have interveinal chlorosis, with the leaf lamina at
first appearing to be a "healthy" yellow.
Leaf Scorch
(drought/winter burn)
Scorch often occurs in July and August, especially on newly planted trees, when the
roots cannot supply enough water to offset the water lost through the leaves in
transpiration. Hot, dry winds will increase the amount and severity of leaf scorch,
especially in the early summer after a cool, wet period.
Symptoms of leaf scorch include yellowing and/or darkening of tissues between
the main leaf veins or along the leaf margins, sometimes with dark angular spots
in the discolored areas. Entire leaves may become brown and wither when leaf
scorch is severe.
Nitrogen Deficiency
The most common plants affected by nitrogen deficiency
include fruit trees, vegetable plants and broad-leafed
evergreens, although any plant can become nitrogen
deficient.
2, 4-D Injury
•
The initial symptom is wilting of the plant leaves