Diseases - PowerPoint PPT Presentation

Diseases

Help me! I’m dying.

• Disease is a plant disorder caused by an infectious pathogen or agent

Host – Plant the disease attacks

Pathogen – Any disease causing agent

Environment – moisture and temperature needed for the pathogen to grow

Single-celled organism

Must remain in host or under debris

Actively divide to spread

Fungi

Multi-cellular

Eats on plants and hurts them in the process

Produces spores that spread

Viruses

Ultramicroscopic parisites

Attack plant tissues

Should destroy plant completely if found

Parasitic plants-

A plant that attaches to another plant

Ex. mistletoe, dodder, lichens

• Must be identified before they can be treated
• Warm temperatures and moist conditions in greenhouse plant production make most horticulture plant diseases worse

• Preventing plant disease through sanitation and insect control is much easier than treating the disease.

Canker sores

Damping off

Galls

Leaf spot

Mildew

Mosaic

Rots

Rust

Smut

Wilt

• Infectious bacterium
• Cause plant to quickly turn brown or black as if they had been burned
• One specific blight is fire blight-devastating apple crops
• Prune 6-8” below infection

• Bacterial disease
• Causes open wounds on woody plant stems

• Fungal disease
• Causes young plants and seedling to rot off at soil level
• Need clean containers and soil and plenty of air circulation between plants

• Round swelling or growths on plants
• Usually caused by an insect that vectors the disease

• Rings of different shades of brown, green, or yellow
• Looks like dots or circles

• Fungus
• Grows on leaf surfaces
• Appears as white, gray or purple spots
• Example is powdery mildew
• Homemade remedy= 2 tsp baking soda + horticultural oil with 1 gal water

• Caused by a virus
• Leaves have irregular mottled areas with patterns
• Ranges from dark green to light green to yellow to white
• Tomato mosaic virus is common in tomatoes

• Fungus
• Causes plants to decay and die
• Usually has a unique smell
• Improve drainage for the plant to prevent

• Fungus
• Causes small spots on leaves
• Resembles yellow, orange, brown or red rust
• Mainly on underneath of leaf

• Black powdery disease
• Causes blisters that burst open
• Releases black spores
• Grows on aphid’s honeydew

• Fungus
• Disease that blocks the uptake of water in plants stems
• Causes plants to look constantly wilted even when adequately watered