Transcript Annual flowers, SWP & vegetable beds

Annual flowers, SWP &
vegetable beds
Cineraria leafminer
Green vegetable bug
Leaf eating ladybirds
Looper caterpillars
Bacterial soft rot
Fungal leaf spots
Sclerotinia
Verticillium wilt
Cineraria leafminer
• Order- Diptera
• Appearance –The adult is a small grey fly
which inserts it’s eggs into the undersides
of leaves. The larvae to 5mm, creamy
white. The pupa are barrel shaped, 2.5mm
• Holometabola
• Damage- Larvae create “mines” by chewing
inside leaf causing pale grey squiggles,
unsightly leaves. Severe infestations retards
growth and eventual death of plant. Egg
laying causes punctures, leaving scars.
First damage usually appears late winter
/spring
• Plants affected-Cineraria, chrysanthemum
(Asteraceae plants), nasturtiums, lettuce,
sow thistle, capeweed
Leafminer control
• Cultural- Remove weeds ( hosts on sow thistle,
capeweed, mist flower)
• Physical – Remove leaves, squash miners inside leaf
(hold towards light to find active miners), fertilise
and water
• Chemical- Spray pest oil to deter (check temp), dust
leaves with ground rock phosphate, Pyrethrum,
garlic/onion spray
Or selected systemic in heavy infestation when
damage first seen.
Check that larvae have not pupated before spraying
Green vegetable bug
• Order- Hemiptera
• Appearance –The adult is shield shaped,
green and can be distinguished by the top
edge of the triangle on their back: it has a
black spot in each corner & 3 yellow
spots between them. The larvae have a
combination of colour changes at each
moult
• Damage- Piercing & sucking, fruits and
seeds mainly affected causing shrivelling
and distortion. Young shoots can also be
damaged
• Plants affected- A wide range of
herbaceous plants & weeds including
pumpkins, capsicum, potatoes, oranges,
peas beans and tomatoes.
Green vegetable bug control
• Cultural – Control weeds, remove plants that have
finished bearing
• Physical – Hand remove at young nymphal stage
• Chemical- Contact –observe withholding period
• Biological- An important predator of the GVB is
the parasitic wasp Trissolcus baslais, which
parasitise GVB eggs. The parasitised eggs are
simple to identify, as they appear black and not the
usual orange colour.
Leaf- eating ladybirds
• Order- Coleoptera
• Appearance – Adults are oval,
6mm, dull yellow orange with 28
spotted, 26 spotted. Larvae yellowgreen covered in black, branched
spines
• Damage-Larvae feed on lower
surfaces& adults appear on upper
surfaces leaving a network of veins.
Each skeletonised patch is crescent
shaped. Fruit can be blemished
• Plants affected- melons, beans,
potatoes, etc SOLANACEAE
BRASSICACEA
• DO NOT CONFUSE WITH 18
SPOTTED LADYBIRD
• ( BENEFICIAL )
Ladybird control
• Physical- hand removal
• Chemical-Spray with Permaguard (ground
diatomaceous earth & pyrethrum), glue spray or
other poison
• Biological-Birds, assassin bugs, soldier beetles,
mantids
Looper caterpillars
Looper caterpillars
• Order- Lepidoptera
• Appearance –Larvae arch the
middle part of body to form a loop,
green-blue, taper to head, thin white
lines. Adults are dark brown with
silver bronze pattern moths
• Damage-Larvae chew on
undersides making ‘windows’.
Older larvae chew ragged holes,
severe infestations can defoliate &
damage fruit
• Plants affected- A wide range of
herbaceous plants
Looper control
• Biological- Birds, wasps, lacewings, scorpion
flies, dragonflies, Dipel ( bacteria)
• Assassin bug ( Pristhesancus) injects an
debilitating enzyme into their prey which
dissolves the inner organs which is then sucked
out leaving an empty shell- compatible to other
biocontrol
• Trichogramma wasp lays her eggs into moth eggs,
emerging wasps parasitise other moth eggs
• Physical- hand remove
• Chemical- Pepper spray, glue spray, Pyrethrum,
Pest oil or other
Benficial Insects
Green Lacewing
Snails and slugs
• Damage?
• Mouthparts
• Control methods??
Bacterial soft rot
• BACTERIA
• Symptoms & Damage- Soft,
depressed areas and mushy decay
with a very offensive odour.
Bacterial slime is often seen on
affected areas
No furry growth - is not fungal
• Plants affected- Wide host of fruits,
tubers, fleshy roots & succulent
buds and stems
• Source of infection- soil & infected
plant material
• Control-Do not over water, do not
dig tubers or storage organs in wet
soil, store in dry conditions. Avoid
damage at harvest time
Bacterial soft rot
Brown spots on the tuber
surface will turn into a creamcoloured rot that rapidly
Decay of wrapper and outer head
destroys the tuber.
leaves
Bacterial soft rot
Decay of core and internal
cabbage head tissue
Fungal leaf spots
• FUNGUS (various)
• Symptoms & Damage- Vary in
shape, size and colour depending
on host and fungus. Often have
concentric rings with red or
yellow coloured borders. Small
yellow specks –enlarge- go pale
brown-dark brown with yellow
halo. Disease starts at base of
plant & moves upward. Also
causes seedling damping-off
• Plants affected- Wide host of
annuals and SWP, high moisture,
• Source of infection- infected
plant material, plant debris, over
wintering mycelium
Fungal leaf spots
• Spread- Free water on leaf
surfaces (esp at night) essential
for spore germination. Prefer
warm nights >250C) and hot,
humid nights. Rain splash,
wind, carried on bodies of
insects, hands of staff and tools
• Rainy periods favour fungi
sporulation and spread to
unaffected foliage. Infection
may occur at any time, but the
disease is usually most severe
on new, emerging foliage
during spring and autumn rainy
periods.
Fungal leaf spots
Cristulariella leaf spot on a
Magnolia leaf
Fungal leaf spots
• Control- Remove & destroy
infected material, do not water
at night water when water may
pool on leaves, ensure clean
stock, spray with Bordeaux,
• Fungi that cause leaf spots form
spores on the leaves. The new
spring infections are commonly
caused by spores from last
autumn leaves. Therefore, rake
and destroy last season's leaves
before buds break in the spring.
• Prune out over thick growth on
deciduous trees and shrubs to
allow better air circulation
Cristulariella on Maple leaves
Fungal leaf spots
Colletotrichum leaf spot. Left, small and large spotson leaf;
right, close-up of leaf lesion with dark specs (acervuli and
setae) in center
Fungal leaf spot on iris.
Fungal leaf spots
Sclerotinia
• FUNGUS
• Symptoms & Damage- Plants may
suddenly wilt, lower leaves turning
yellow. Plants often topple over at the
point of infection which is usually
near ground level. Characteristic
symptoms are a brown, soft, wet rot
with an associated mass of fluffy
white mould which contains large
hard dark bodies, called sclerotia.
• worse in cool, wet weather (100250C).
• Plants affected-Herbaceous plants
• Source of infection-Sclerotia in
plant debri and soil, infected plants
Sclerotinia
• Spread- wind blown spores
from germinating sclerotia
More common during
Autumn, Winter and
Spring. Disease can show
up in storage eg.
refrigerators which are not
cooling properly
Sclerotinia
Control
• Remove & destroy infected
material,
• crop rotation- avoid planting
susceptible crops in affected area
for four years-Sclerotia can
remain viable in the soil for up to
seven years.
• Use resistant plants
• Regular cultivation removes
weeds, lowers humidity around
plants and destroys germinating
sclerotia
• Improve drainage and spacing
plants will reduce humidity
Verticillium wilt
• FUNGUS
• Symptoms & Damage- The soil
inhabiting fungus enters through
root hairs, lower leaves are usually
first to go and have pink –purple
tinge or wilt & dry, become
yellow, light brown base of stem
• Plants affected-Wide range
• Source of infection- Infested soil.
Mycelium enters roots and blocks
xylem tissue
• Spread- wind, water, soil, infested
cuttings, tools, cool conditions,
waterlogging, high N
Cross-section of a tree trunk. The
wood composed of xylem laid
down in the form of annual rings.
Verticillium wilt
Verticillium wilt typically causes the
margins of leaves to turn brown giving the
leaf a scorched appearance.
Wilting and yellowing of leaves
Verticillium wilt
Maple tree infected with
Verticillium wilt
Black raspberry plants wilting from
Verticillium wilt.
Verticillium wilt
Symptoms of Verticillium Wilt in olive groves
Verticillium wilt
• Control
Remove & destroy
infected material, crop
rotation, improve
drainage, use resistant
cvs, control weeds,
hygiene, tools, do not
propagate from
infected plants
Sapwood discoloration in maple
twig.