CROP PROTECTION

MID TERM EXAM

Pathogen

Any agent that cause disease especially the biotic and living agent

Parasites

an organism which depends wholly or partially on another living organism

Parasitism

the removal of food by a parasite from host

Saprophyte

an organism that uses dead organic material for food

Obligate parasites

an organism that in nature can grow and multiply only in living organism also called as biotrophs

Facultative Parasites

A parasite that live most of the time and thrive on dead organic matter, but under certain circumstances, may attack living plants and become parasitic. Also called necrotrophs

Facultative saprophytes

A parasites that live most of the time or most of their life cycles as parasites, but under certain conditions, may grow saprophytically on dead organic matter. Also called semibiotrophs

Host

A plant that is being attacked by a parasite and from which the parasite obtains its nutrients

Suscept

Any plant that can be attacked by a pathogen; a host plant

Pathogenecity

The capability of a pathogen to cause disease

Virulence

Quantitative amount of disease that an isolate (the pathogen) can cause in a group of plants

Disease Cycle

The chains of events involved in disease development including the stages of development of the pathogen and the effect of the disease on the host.

Inoculation

The arrival or transfer of a pathogen onto a host

Inoculum

The pathogen or its parts that can cause infection; that portion of individual pathogens that are brought into contact with the host

Infection

The establishment of a parasite within a host plant

Infested

Containing great numbers of insects, mites, nematodes, etc. as applied to an area or field

Disinfectant

A physical or chemical agent that frees a plant; organ; or tissue from infection

Symptoms

The external and internal reactions or alterations of a plant as a result of disease

Symptom Complex

Different symptoms exhibited by the plant

Signs

The pathogen or its parts or products seen on a host plant

Microscopic

Very small; can be seen only with the aid of a microscope

Pathogenesis

The process by which an infection leads to disease

Resistance

the heritable ability of plants to escape attacking enemies, partially or fully, thus minimizing the amount of damage experienced by the plan

Tolerance

the ability or willingness to tolerate something; a plant that tolerates a certain amount of shade but also develops well

Primary Symptoms

immediate and direct results of the causal agent’s activities on the invaded tissues

Localized Symptom

distinct and limited expression

Histological symptoms

expression that are observed only under a microscope examination

Hypoplastic Symptoms

inhibition or failure in the development of some aspect of plant growth as in stunting

Hyperplastic Symptoms

overdevelopment of plant tissues as in gall formation

Plant Disease Diagnostic

is the identification of specific plant disease through their characteristics symptoms and signs including factors related to disease development

Tolerance

ability of plant to withstand the severe effects of the pathogen without experiencing a severe reduction in yield

Masked Symptoms

symptoms not expressed due to unfavorable condition

Symptomless Carrier

a host that do not show symptom irrespective of environment

Virulence

refers to the quantitative amount of disease that can isolate of a given pathogen can cause in a given group of plants in terms of size of lesions or number of lesions

Aggressiveness

measures the rate at which virulence is expressed by a given pathogenic isolate