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Physiological or abiotic disorders are mainly caused by changingenvironmental conditions such as temperature, moisture, unbalancedsoil nutrients, inadequate or excess of certain soil minerals,extremes of soil pH and poor drainage. The distinction betweenphysiological or abiotic disorders from other disorders is thatthey are not caused by living organisms (viruses, bacteria, fungi,insects, etc.), but they are the result of abiotic situations(inanimate) i.e. their agents are non-living in nature which causesdeviation from normal growth. They results in physical or chemicalchanges in a plant which is far away from what is normal and isgenerally caused by an external factor. Non-infectious disorders insome cases are easy to identify, but others are difficult or evenimpossible to recognize. Most of them are non reversible once theyhave occurred. for the identification of physiological disorders itis important that one must know that: a) Physiological disordersare often caused by the deficiency or excess of something thatsupports life or by the presence of something that interferes withlife.
b) Physiological disorders can affect plants in all stages oftheir development.
c) They are non-transmissible because they occur without or inabsence of infectious agents.
d) Plant reacts differently to the same agent and sometimesresponse is seen as a little reaction to death.
e) Dealing with physiological disorders often means dealing withthe consequences from a past event.
f) Generally damaged and undamaged tissue is clearlydemarcated.
g) Physiological disorders not only causes damage themselves butalso serve as the open door (entry) for pathogens.ISBN - 9789381450581
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Pages : 213
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