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 ...
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. 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 resul ...
genus ''
Phytophthora''; 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, ...
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 segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and cuticle made of chiti ...
s in the soil.
It can be controlled by drenching
carbendazim
Carbendazim is a widely used, systemic, broad-spectrum benzimidazole fungicide and a metabolite of benomyl. It is also employed as a casting worm control agent in amenity turf situations such as golf greens, tennis courts etc. and in some countr ...
.
Hydroponics
Root rot can occur in
hydroponic applications, if the water is not properly
aerated. 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 a ...
,
air stone An airstone, also called an aquarium bubbler, is a piece of aquarium furniture, traditionally a piece of limewood or porous stone, whose purpose is to gradually diffuse air into the tank, eliminating the noise and large bubbles of conventional air ...
s,
air diffusers 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.
Particular diseases
*
Armillaria causes
Armillaria root rot or white rot root disease
*
Rhododendron root rot
*
Shoestring root rot
*
Texas root rot
* ''
Rosellinia necatrix
''Rosellinia necatrix'' is a fungal plant pathogen infecting several hosts including apples, apricots, avocados, cassava, strawberries, pears, hop. citruses and ''Narcissus
Narcissus may refer to:
Biology
* ''Narcissus'' (plant), a genus co ...
'' aka ''Dematophora necatrix''
* ''
Scytinostroma galactinum'' aka ''Corticium galactinum''
* ''
Phytophthora'' – see ''
Phytophthora cinnamomi'' for discussion on treatment
See also
* ''
Pythium''
* ''
Rhizoctonia''
*
Plant pathology
Plant pathology (also phytopathology) is the scientific study of diseases in plants caused by pathogens (infectious organisms) and environmental conditions (physiological factors). Organisms that cause infectious disease include fungi, ...
*
Damping off – root rot in seedlings
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