Pest Control of Interior Plants - LHAP 303

1. Pest Control Of Interior Plants

Google Slides Presentation By: Crystal Price

2. Botrytis (Grey Mold)

Tissue that looks brown, wet & necrotic Lesions develop as tan or brown water-soaked areas

• May become greyish upon drying out

Characteristic sign of the disease is fuzzy grey spore masses

Overwinters in the soil & plant debris Spores favor under cool moist conditions

• Spores are airborne

3. Prevention & Control

Ensure good air circulation Reduce RH if possibly by heating or venting

• Avoid overcrowding

Strict sanitation & cultural practices Prevent outbreak

Prevent water drip on leaves from roof condensation & overhead sprinklers

Remove dead or diseased plant material ASAP Quarantine new plant material until it has been inspected

• Or isolated until proven disease free

4. Add a layer of mulch under the plants

Prevents the fungal spores from splashing onto flowers & leaves

• Good irrigation practices
• Early morning watering

Drip irrigation or soaker hose Do not compost infected leaves

Copper fungicide Liquid Copper Broad Spectrum (Fungal & Bacterial Disease Control)

Serenade Disease Control Serenade Garden Broad Spectrum

• Biofungicide (Fungal & Bacterial Disease Control)
• Bacillus subtilis

Fungus & nematode species have been used to control this mold effectively

5. Powdery Mildew

Whitish grey patches & spores of mycelium

Most prevalent on upper leaf surface but will spread to lower leaf surfaces

Attacks flowers and stems as well Fungus penetrates the plant cells and feeds from them

Loss of blooms and reduction in plant vigor and appearance

6. Prevention & Control:

• Good air circulation

Maintain optimum growing temperatures Strict hygiene (PM can live on plant debris)

• Water the soil not the leaves

Remove & dispose of infected leaves or entire plant to stop the spread

7. Bacterial Diseases

Relatively few compared to fungal diseases Similar problems such as leaf spots, blight, rots & wilt

Sometimes you can only see the differences through a microscope

It is important to be sure of the cause before a treatment program

• Most fungicides will not control bacteria

8. Bacterial Leaf Spots

Usually circular or angular water-soaked areas Might be light green or yellow becoming brown

Sometimes a halo can be seen around the center of the lesion

Some spots may exude ooze of various colors Spots may be bicolored

Bacteria use vascular system as a means of spreading

9. Rots & Blights

• Often soft and slimy
• Sometimes a distinct odor

First signs may be wilting due to blockage of the vascular system

On woody plant parts a sticky ooze & foul odor indicate bacterial disease

10. Prevention and Control

• Avoid wetting foliage

Disinfect cutting tools & propagation tools Apply fixed copper 50WP

• Copper oxychloride (200g/100L)

Broad spectrum fungicide that controls fungal & bacterial diseases

• Serenade
• Copper Fungicide

11. Viral Diseases

• Shows up in the leaves first

Color changes, spots, streaked rings & various mottled patterns

Dwarfed leaves, rolling or puckering may also be present

Same symptoms apply to flowers as well as streaked or off color petals

Viruses usually require a vector to be transmitted

• Insects or mechanical handling

Positive ID can only be made by sending in leaf samples to be tested

Often resembles other physiological disorders Some plants may only exhibit poor or slow growth

12. Prevention & control

• Control insect pests

Sanitation during propagation Destroy plants showing symptoms

Keep stock plants separate from young plants (Quarantine)

13. Insects

• Aphids
• Referred to as plant lice

Black, grey or red to yellow, or green Adults are winged or wingless

Found on new buds or under leaves Look for:

Deformed leaves and flowers Sticky substance on leaves

• From excretions

Transmit virus - yellowing or distorted leaves

14. Prevention & Control

Monitoring is the best prevention Inspect new foliage continuously

• Keep plants healthy

Less prone to attacks than a sick plant If they are spotted wipe down with a moist cloth

• Release biological controls Ladybird beetles/larva

Prune badly infected leaves or removal of the entire plants is sometimes best

15. Fungus Gnats Other ways to get rid of fungus gnats

Big problem in soilless mediums with a high OM or peat content

• Grey-black about 4mm long

Adults are weak flyers and frequently observed walking on the media surface

• Do not cause any damage

Larvae have 12 abdominal segments and a shiny black head

Feed on young roots of plants and decaying organic matter

Root feeding causes various root rot organisms More active during warmer temperatures

Attracted to humidity, high temps., and decomposing organic matter

16. Prevention & Control

Allow soil to dry out at a depth of one to two inches between waterings

Kills larvae & inhibits development of eggs Soil is less attractive to egg-laying females

Consistency is key using sticky traps places directly on top of soil

Cider-vinegar traps placed near the base of the plants or on top of soil surface

Apple-cider vinegar, few drops of dish soap in a small shallow container (¼ inch deep)

• Check every few days to refresh

Top dress with beneficial nematodes to destroy larvae stage Beneficial Nematodes

• Destroys the larval stage

Safe to use around pets, plants and your family Spreads pythium.

Plant pathogen that cause damping off Issues with young delicate plants

17. Diatomaceous earth

Apply when the soil is dry, or on top of sand and water from below

Keep soil dry, allow to dry out a bit between waterings (top 1” or 2”)

Mosquito dunks - product contains a dry pellet containing Bacillus thuringiensis

18. 200 eggs per female

19. Thrips

Several species including flower thrips, onion thrips, Chrysanthemum and greenhouse thrips

Tiny, slender, agile insects 1 - 2 mm in length

Adults are dark brown or yellowish brown in color

Adults are weak flyers, short flights from leaf to leaf

Young thrips are white or yellow with red eyes Rasping sucking mouthparts

• White streaked areas of flower petals

Toxic substances are present in the saliva causing some deformations to occur in shoots & flowers

• Thrip Life Cycle

20. Early symptoms are almost transparent or clear discoloration of the leaf

Early symptoms are almost transparent or clear discoloration of the leaf.

Majority of plant damage is done by the larvae.

21. Tomato Spotted Wilt Virus (Tospovirus)

Causes significant crop loss and they are incurable.

22. Prevention & Control

Monitoring by sticky traps to track population Cultural Control

Sanitation (Clean Stock) Removal of flower heads

• High RH 80%, create less favourable conditions for thrips
• Physical Control

Physically screen to restrict movement into the growing space

Biologicals is the primary strategy as development to most registered pesticides (potassium soap or plant extracts with pyrethrum)

Predatory Mites introduced at the beginning of plantings, more effective

• Predatory Bugs for Thrips
• Mites

23. WhiteFlies

• Difficult to control

Adults are small, winged insects, white in color about 1.5 mm in length

Eggs are laid on the underside of leaves Appear as a ring of of small black specks

Females can lay up to 400 eggs and live as long as 2 months

Nymphs are flat and saclike and move over the plant before settling down

Piercing mouthparts allow them to remove sap in large amounts

Produce large amounts of honeydew, allowing black sooty mold fungus to grow

New leaf tissue preferred by the nymphs

Can be found feeding on underside of leaves showing wilt symptoms

Adults and exoskeletons may be found on lower leaves with signs of wilt

• Whitefly Life cycle

24. Prevention & Control

Prevention - Regular monitoring under the leaves

Isolate new stock, screening, sanitation, Knock off with the hose

• Organic or non-organic insecticidal soaps Vacuum

Sticky traps - yellow Biologicals - Parasitic wasps

• Biological Wasp

25. Spider Mites

Two-Spotted Spider Mite Prefer a hot dry environment with no air circulation

Small and orange that inflict stippling Appear as very small dots on the leaf surface

Take a sheet of paper and tap the leaf over top of it to identify infestation (very small orange specs that are mobile)

• Look under the leaf
• May find webbing in bad infestations

26. Prevention & Control

• Regular scouting

Look under the leaves with a magnify glass Look for fine webbing

Blast off with a high pressure spray of water Vacuum

• Lower temperature (below 25 C)

Increase RH (60%),air circulation, adequate watering practices

Sanitation & remove leaf litter Biological controls

27. Mealy Bug

Appear first as a white, cottony substance on the plant

Generally you will find hiding in crevices of leaves/leaf axils

• Like warmer conditions
• Soft bodied wingless

Feed by inserting long sucking mouth parts, called stylets into the plant drawing out sap

Nymphs are crawlers - light yellow and free of wax

• Low populations do not cause significant damage

Feeding accompanied by honeydew, making the plants sticky and encouraging growth of sooty molds

Move little once a feeding site is found Mealybug Life cycle

28. Early detection and cleaning of leaves

Q-tip or cotton pad dipped in rubbing alcohol Do not over fertilize or reduce nitrogen

Attracted to soft new growth Blast off with high pressure water

• Neem oil
• Botanical insecticides
• Washing foliage
• Biological controls Cryptobug
• Biological control

29. Scale

Soft or hard bodied depending on species All are sap feeding with piercing sucking mouthparts

Soft scale are ¼” long and secrete copious amounts of honeydew causing sooty mold

Hard bodied or armoured scale are a little bit smaller

No visible head or legs and no honeydew

The female and immature forms hide under a waxy shell & do not move

Large infestations will weaken the plant and sometimes distort leaves

30. Prevention & Control

Regular scouting - prune and dispose of infested leaves, twigs & branches

• Rub or pick off with hands

Dabbing individual pests with rubbing alcohol or neem-based leaf shine

Ladybird beetles & lacewings of the young crawler stage

AzaMax is a insect growth regulator (Antifeedant)

Horticultural oils or oil based insecticidal kill all pest stages

• Botanical insecticides as a last resort