AC-Ch. 10 Diagnosis & Plant Disorders Flashcards
Disorder or disease that occurs suddenly or over a short period of time
Acute
With oxygen. Process that occurs in the presence of oxygen
Aerobic
Chemical effect or inhibition of growth or development of plants that is induced by allelochemicals.
Allelopathy
Without oxygen. Process that occurs in the absence of oxygen.
Anaerobic
Disorder caused by an infectious living agent.
Biotic disorder
Any disease or disorder regardless of the causal agent that kills young plant tissues
Blight
Localized diseased area on stems, roots, and branches. Often shrunken and discolored
Canker
Whitish or yellowish leaf discoloration caused by lack of chlorophyll. Often caused by nutrient deficiency.
Chlorosis
Disorder or disease occurring over a long period of time
Chronic
Combination of factors contributing to the stress or decline of a tree
Complex
An area of wood that is undergoing decomposition
Decay
Decomposition of organic tissues by fungi or bacteria
Decay
Loss of leaves from a tree or other plant by biological or mechanical means.
Defoliation
Condition in which the branches in the tree crown die from the tips toward the center
Dieback
Fecal material and/or wood shavings produced by insects
Frass
Vertical split in the wood of a tree generally near the base of the bole caused by internal stresses and low temperatures. Radial shake
Frost crack
Abnormal swelling of plant tissues caused by gall wasps, mites, nematodes, and various insects and less commonly by fungi or bacteria.
Gall
Exudation of sap or gum from the bark often in response to disease or insect damage
Gummosis
Sugary substance secreted by certain insects including aphids and some scale insects when feeding on plants.
Honeydew
Capable of being spread to plants from other plants or organisms
Infectious
Irregularly shaped areas of disease on plant foliage
Leaf blotch
Patches of disease or other damage on plant foliage.
Leaf spot
Localized death of tissue in a living organism.
Necrosis
Microscopic roundworm. Many are beneficial organisms but some feed on plant tissues and may cause disease or damage
Nematode
Disorders that are not caused by a pathogen and cannot be passed from one host to another
Noninfectious
Causal agent of disease. Usually refers to microorganisms.
Pathogen
In plants a disorder not directly caused by an insect, pathogen or injury
Physiological disorder
Plant malady caused by nonliving, environmental, or man-made agents
Abiotic disorder
Any of various fungi of the genus Erysiphe that produce powdery conidia that appear as a white fuzzy coating on the upper leaf surfaces often causing distortion of the leaf.
Powdery mildew
Disease caused by a certain group of fungi and characterized by reddish brown spots on the foliage and/or the formation of stem galls.
Rust
Browning and shriveling of foliage, especially at the leave margin.
Scorch
Physical evidence of a casual agent
Sign
Leaf-feeding damage caused by insects, characterized by the loss of tissue between the leaf veins.
Skeletonized
Fungus that appears as a black coating on the surface of leaves, fruits, branches, and other surfaces. Often found growing on sugary honey dew excreted by aphids.
Sooty mold
Growth reduction of organisms, specifically plants or plant parts.
Stunting
Plant reaction to a disease or disorder.
Symptom
Substance that moves throughout an organism after it is absorbed
Systemic
Any condition, disease, disorder, or pest that affects the entire organism.
Systemic
Factor that negatively affects the health of a plant; a factor that stimulates a response
Tree stress
Transition zone from trunk to roots where the trunk expands into the buttress or structural roots.
Trunk flare
Darkening of the vascular tissues of woody plants in response to disease
Vascular discoloration
In pathology, biotic or abiotic agent that transmits a pathogen.
Vector
In mechanics or rigging, quantity that has both magnitude and direction.
Vector
Loss of turgor and subsequent drooping of leaves and young stems; a symptom.
Wilt
Infectious disease caused by a particular agent on a particular host or range of hosts.
Wilt
To lose turgor.
Wilt
Plant disorder characterized by a shortening of the internodes And a proliferation of terminal shoots forming a dense, brush like mass of twigs.
Witch’s broom
