Ectoparasite: a parasite feeding on host from the outside

Egg: a female gamete; in nematodes it is the first stage of the life cycle containing a zygote or a juvenile

ELISA (Enzyme linked immunosorbent assay): a serological test in which one antibody carries with it an enzyme that releases a colored compound

Endoparasite: a parasite that enters and infects the host

Epidemic: a widespread and rapidly outbreak of disease in a population

Epidemiology: the study of the factors affecting an outbreak and spread of infectious disease

Epiphytically: existing on the surface of a plant or plant organ without causing infection

Eradicant: a chemical substance that destroys pathogens at its source

Eradication: control of plant disease by destroying or removing a pathogen or pest after is has been established in an area

Etiology of disease: the determination and study of the cause of disease

Filamentous: threadlike or filiform

Flagellum: a hair-, whip-, or thread-like filament projecting from some bacteria or fungal zoospores allowing them to travel through a liquid

Forma specialis (f. sp.): a group of races and biotypes of a pathogen species that can infect only plants within a certain host genus or species

Fructification: production of spores by a fungus. Also a fruiting stucture in which spores are formed

Fruiting body: a complex fungal structure that contains or bears spores. Example: acervulus, apothecium, etc.

Fumigant: a toxic gas or volatile material used to keill disease-causing organisms

Fungicide: chemical or physical agent that is toxic to fungi

Fungistatic: a chemical or physical agent that inhibits the growth, sporualtion, or spore germination of fungi but does not cause death

Gall: abnormal swelling or localized growth (tumor) found on leaves, stems, roots, and other plant parts, produced by plant cells in response to attack by pathogen

Gametangium: a differentiated structure containing gametes

Genetic engineering: the alteration of the genetic material of an organism by various tissue culture procedures

Germ tube: early growth of mycelium produced by spore that is germinating or beginning to grow

Grafting: method of plant propigation involving the transplantation of a bud or scion of a plant to another plant

Gummosis: pathogenic condition in which a plant secrets excessive amounts of sap, "gum", latex, or resin by or in a plant tissue

Guttation: exudation of water and solutes from the hydathodes of plants

Haustorium: a simple or branched projection of hyphae into host cells which acts as an absorbing organ

Hectare: a land area equivalent to 2.5 acres

Heteroecious:requiring two unrelated host to complete life cycle, example rust funji

Heterokaryosis: condition in which a mycelium contains two or more slightly genetically different nuclei per cell

Horizontal resistance: partial resistance equally effective against all races of the pathogen

Host: a living organism containing or invaded by a parasite which obtains its nutrients from the organism

Host range: various kinds of plants that may be attacked by a parasite

Hyaline: clear, colorless, transparent

Hyperplasia: a plant overgrowth due to the excessive dividing of cells

Hypersensitivity: excessive sensitivity of plant tissues, such as rapid death of cells at the point of attack by a pathogen, so infection does not spread

Hypertrophy: a plant overgrowth due to abnormal cell enlargement

Hypha: a single branch of mycelium

Hypovirulence: reduced pathogen virulence due to the presence of a transmissable double-stranded RNA