Root rot is a condition in which

anoxic The term anoxia means a total depletion in the level of oxygen, an extreme form of hypoxia or "low oxygen". The terms anoxia and hypoxia are used in various contexts: * Anoxic waters, sea water, fresh water or groundwater that are depleted of diss ...

conditions in the

soil Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former te ...

or potting media around the roots of a plant cause them to rot. This occurs due to excessive standing water around the roots. It is found in both indoor and outdoor plants, although it is more common in indoor plants due to overwatering, heavy potting media, or containers with poor

drainage Drainage is the natural or artificial removal of a surface's water and sub-surface water from an area with excess of water. The internal drainage of most agricultural soils is good enough to prevent severe waterlogging (anaerobic conditio ...

. The leaves of plants experiencing root rot often yellow and die, and if allowed to continue, the condition can be fatal. To avoid root rot, it is best to only water plants when the soil becomes dry, and to put the plant in a well-drained pot. Using a dense potting media such as one dug up from outdoors can also cause root rot. Plants from different environments have different tolerances for soil moisture: plants evolved for desert conditions will experience root rot at lower moisture levels than plants evolved for tropical conditions. In both indoor and outdoor plants, it can be lethal and there is no effective treatment, though some plants can be propagated so they will not be lost completely. The best course of action is to repot the plant and cut out any dead tissue. Many cases of root rot are caused by members of the

water mold Oomycota forms a distinct phylogenetic lineage of fungus-like eukaryotic microorganisms, called oomycetes (). They are filamentous and heterotrophic, and can reproduce both sexually and asexually. Sexual reproduction of an oospore is the result ...

genus ''

Phytophthora ''Phytophthora'' (from Greek language, Greek (''phytón''), "plant" and (), "destruction"; "the plant-destroyer") is a genus of plant-damaging oomycetes (water molds), whose member species are capable of causing enormous economic losses on cro ...

''; perhaps the most aggressive is ''P. cinnamomi''.

Spore In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...

s from root rot causing agents do contaminate other plants, but the rot cannot take hold unless there is adequate moisture. Spores are not only

airborne Airborne or Airborn may refer to: Arts, entertainment, and media Films * ''Airborne'' (1962 film), a 1962 American film directed by James Landis * ''Airborne'' (1993 film), a comedy–drama film * ''Airborne'' (1998 film), an action film sta ...

, but are also carried by insects and other

arthropod Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arth ...

s in the soil. It can be controlled by drenching carbendazim.

Hydroponics

Root rot can occur in

hydroponic Hydroponics is a type of horticulture and a subset of hydroculture which involves growing plants, usually crops or medicinal plants, without soil, by using water-based mineral nutrient solutions in aqueous solvents. Terrestrial or aquatic plan ...

applications, if the water is not properly

aerated Aeration (also called aerification or aeriation) is the process by which air is circulated through, mixed with or dissolved in a liquid or other substances that act as a fluid (such as soil). Aeration processes create additional surface area in ...

. This is usually accomplished by use of an

air pump An air pump is a pump for pushing air. Examples include a bicycle pump, pumps that are used to aerate an aquarium or a pond via an airstone; a gas compressor used to power a pneumatic tool, air horn or pipe organ; a bellows used to encourage ...

, air stones,

air diffuser The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing for ...

s and by adjustment of the frequency and length of watering cycles where applicable. Hydroponic air pumps function in much the same way as aquarium pumps, which are used for the same purpose. Root rot and other problems associated with poor water aeration were principal reasons for the development of

aeroponics Aeroponics is the process of growing plants in the air or mist environment without soil or an aggregate medium. The word "aeroponic" is derived from the Greek meanings of ''aer'' ("air") and ''ponos'' ("labour"). It is a subset of hydroponic ...

Particular diseases

Armillaria ''Armillaria'' is a genus of fungi that includes the ''Armillaria mellea, A. mellea'' species known as honey fungi that live on trees and woody shrubs. It includes about 10 species formerly categorized summarily as ''A. mellea''. ''Armill ...

causes

Armillaria root rot Armillaria root rot is a fungal root rot caused by several different members of the genus ''Armillaria''. The symptoms are variable depending on the host infected, ranging from stunted leaves to chlorotic needles and dieback of twigs and branch ...

or white rot root disease *

Rhododendron root rot ''Phytophthora cactorum'' is a fungal-like plant pathogen belonging to the Oomycota phylum. It is the causal agent of root rot on rhododendron and many other species, as well as leather rot of strawberries. . Hosts, symptoms, and diagnosis ' ...

Shoestring root rot Shoelaces, also called shoestrings (US English) or bootlaces (UK English), are a system commonly used to secure shoes, boots, and other footwear. They typically consist of a pair of strings or cords, one for each shoe, finished off at both e ...

Texas root rot Texas root rot (also known as Phymatotrichopsis root rot, Phymatotrichum root rot, cotton root rot, or, in the older literature, Ozonium root rot) is a disease that is fairly common in Mexico and the southwestern United States resulting in sudden ...

* ''

Rosellinia necatrix ''Rosellinia necatrix'' is a fungal plant pathogen infecting several hosts including apples, apricots, avocados, cassava, strawberries, pears Pears are fruits produced and consumed around the world, growing on a tree and harvested in the N ...

'' aka ''Dematophora necatrix'' * ''

Scytinostroma galactinum ''Scytinostroma galactinum'' is a fungal plant pathogen infecting apple An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple trees are cultivated worldwide and are the most widely grown species in the ...

'' aka ''Corticium galactinum'' * ''

'' – see ''

Phytophthora cinnamomi ''Phytophthora cinnamomi'' is a soil-borne water mould that produces an infection which causes a condition in plants variously called " root rot", "dieback", or (in certain ''Castanea'' species), "ink disease". The plant pathogen is one of the wo ...

'' for discussion on treatment

References

* Shurtleff, Malcolm C. (1962) ''How to Control Plant Diseases in Home and Garden'' Iowa State University Press, Ames, Iowa, p. 73; * Yepsen, Roger B. Jr. (1976) ''Organic plant protection: a comprehensive reference on controlling insects and diseases in the garden, orchard and yard without using chemicals'' Rodale Press, Emmaus, PA, pp. 194, 208, 212–213, 226, 247, 260, 295, 321, 333, 337, 469, 488, 577, and 629, ; * Ellis, Barbara W. and Bradley, Fern Marshall (eds.) (1992) ''The Organic gardener's handbook of natural insect and disease control: a complete problem-solving guide to keeping your garden & yard healthy without chemicals'' Rodale Press, Emmaus, PA, p. 401, ; {{DEFAULTSORT:Root Rot Plant pathogens and diseases

Hydroponics

Particular diseases

See also

References