PLSC 260 - Lecture 1

Phytopathology

The study of plant disease, including causes, symptoms, and management.

Symptoms

Visible reactions of a plant to disease, which may include chlorosis, necrosis, galls, cankers, and wilts.

Abiotic Stresses

Non-living environmental factors that cause plant disease, such as nutrient deficiency and weather conditions.

Pathogen

An organism that causes disease by removing water or nutrients and inhibiting plant development.

Parasitism

The stealing of food by a parasite, an organism that lives on or in a host at the expense of the host.

Pathogenicity

The ability of a pathogen to interfere with a plant's essential functions.

Host Range

The number of host species a pathogen can infect, ranging from narrow to wide.

Biotrophic Parasitism

A strategy where pathogens use living plants as nutrient sources, absorbing nutrients without immediately killing them.

Necrotrophic Parasitism

A strategy where pathogens kill plant tissues and then consume them.

Disease Triangle

The model which states that a diseased condition requires a host, a pathogen, and a conductive environment.

Phytotoxicity

Negative effects on a plant due to a specific chemical substance, often unintentional.

Saprophytic

Organisms that live on dead organic matter without killing their host.

Symbiotic (Endophytes)

Good parasites that live in the plant, using its nutrients while providing additional benefits.

Chlorosis

Yellowing of plant tissue, often a symptom of disease or nutrient deficiency.

Gall and Tumours

Abnormal growths on plants, which can be symptoms of disease.

Cankers

Localized dead tissue on a plant, typically a sign of disease.

Wilts

A condition where parts of a plant are dried or drooping, indicating a disease.

Nutrient Deficiency

A lack of essential nutrients which can cause symptoms similar to disease.

Herbicides

Chemicals designed to kill unwanted plants, which can cause phytotoxicity in crops.

Fungi

A class of biotic stressors that are common pathogens in plants.

Nematodes

Parasitic animals that can cause disease in plants without direct physical damage like insects.