Editing Rust (fungus) (section)

==Management==
===Research===
Efforts to control rusts began to be scientifically based in the 20th century.<ref name="Staples-2000">{{cite journal | year=2000 | issue=1 | volume=38 | publisher=[[Annual Reviews (publisher)|Annual Reviews]] | first=Richard | s2cid=4861612 | pmid=11701836 | pages=49–69 | doi=10.1146/annurev.phyto.38.1.49 | issn=0066-4286 | journal=[[Annual Review of Phytopathology]] | title=Research on the Rust Fungi During the Twentieth Century | last=Staples}}</ref> [[Elvin C. Stakman]] initiated the scientific study of [[host resistance]], which had heretofore been poorly understood and handled by individual growers as part of the [[plant breeding|breeding process]].<ref name="Staples-2000" /> Stakman was followed by [[H. H. Flor]]'s extensive discoveries of rust genetics.<ref name="Staples-2000" /> In order to study rust [[metabolism|metabolics]], Tervet ''et al.'', 1951 developed the {{Vanchor|Cyclone Separator}}.<ref name="Staples-2000" /> The cyclone separator uses the [[cyclonic separation]] mechanism to allow the mechanised collection of spores for study – Cherry & Peet 1966's improved version gathers even more efficiently.<ref name="Staples-2000" /> This device was first put to work testing the composition of the spores themselves, especially substances coating the outside of the spores which [[quorum sensing|signal population density]].<ref name="Staples-2000" /> When detected they help prevent crowding.<ref name="Staples-2000" />

[[Gene cloning]] and other methods of [[genetic engineering]] can provide a much wider range of [[R gene]]s and other sources of rust resistance – with reduced delay before deployment – if [[regulation of genetic engineering]] permits.<ref name="Reveal rust R genes">{{Cite journal|journal=Plant Biotechnology Journal|year=2023|pages=1938–1951|volume=21|issue=10|last1=Dracatos|first1=Peter M.|last2=Lu|first2=Jing|last3=Sánchez-Martín|first3=Javier|last4=Wulff|first4=Brande B.H.|s2cid=260201756|pmid=37494504|doi=10.1111/pbi.14106|title=Resistance that stacks up: engineering rust and mildew disease control in the cereal crops wheat and barley|pmc=10502761 }}</ref>

===Control===
{{More citations needed section|date=October 2023}}

The control methods of rust fungus diseases depend largely on the life cycle of the particular pathogen. The following are examples of disease management plans used to control macrocyclic and demicyclic diseases:

Macrocyclic disease: Developing a management plan for this type of disease depends largely on whether the [[urediniospore]]s (rarely termed the "repeating stage") occur on the [[crop|economically important host plant]] or the [[alternate host]].{{Citation needed|date=September 2023}} For example, the repeating stage in [[white pine blister rust]] disease does not occur on white pines but on the alternate host, ''[[Ribes]]'' spp. During August and September ''Ribes'' spp. give rise to [[teliospore]]s which infect white pines. Removal of the alternate host disrupts the life cycle of the rust fungi ''[[Cronartium ribicola]]'', preventing the formation of basidiospores which infect the primary host. Although spores from white pines cannot infect other white pines, survival spores may overwinter on infected pines and reinfect ''Ribes'' spp. the following season. Infected tissue is removed from white pines and strict quarantines of ''Ribes'' spp. are maintained in high risk areas.{{Citation needed|date=September 2023}}

''[[Puccinia graminis]]'' is a macrocyclic [[heteroecious]] fungus that causes wheat stem rust disease.{{Citation needed|date=September 2023}} The sexual stage in this fungus occurs on the alternate host – [[barberry]] – and not wheat. The durable spore type produced on the alternate host allows the disease to persist in wheat even in more inhospitable environments. Planting resistant crops will prevent disease, however, virulence mutations will give rise to new strains of fungi that overcome plant resistance.{{Citation needed|date=September 2023}} Although the disease cannot be stopped by removal of the alternate host, the life cycle is disrupted and the [[rate of evolution]] is decreased because of reduced [[genetic recombination]]. This allows resistance bred crops to remain effective for a longer period of time.<ref name="Schumann, G. 2010"/><ref name="Marsalis, M. 2006">Marsalis, M. & Goldberg, N. (2006). Leaf, Stem, And Stripe Rust Diseases of Wheat. [Fact sheet]. New Mexico State University. http://pubs.nmsu.edu/_a/A415/ {{Webarchive|url=https://web.archive.org/web/20221127075223/https://pubs.nmsu.edu/_a/A415/ |date=2022-11-27 }}</ref>

Demicyclic disease: Because there is no repeating stage in the life cycle of demicyclic fungi, removal of the primary or the alternate host will disrupt the disease cycle.{{Citation needed|date=September 2023}} This method, however, is not highly effective in managing all demicyclic diseases. Cedar-apple rust disease, for example, can persist despite removal of one of the hosts since spores can be disseminated from long distances. The severity of cedar-apple rust disease can be managed by removal of basidiospore producing galls from junipers or the application of protective fungicides to junipers.<ref>Wallis, C. & Lewandowski, D. (2008). Cedar Rust Diseases of Ornamental Plants. [Fact Sheet]. Ohio State University. https://woodlandstewards.osu.edu/sites/woodlands/files/d6/files/pubfiles/3055%20cedar%20rust.pdf {{Webarchive|url=https://web.archive.org/web/20210107071958/https://woodlandstewards.osu.edu/sites/woodlands/files/d6/files/pubfiles/3055%20cedar%20rust.pdf |date=2021-01-07 }}</ref>

====Home control====
Rust diseases are very hard to treat. [[Fungicide]]s, such as [[Mancozeb]], may help but may never eradicate the disease.{{Citation needed|date=September 2023}} Some organic preventative solutions are available and sulphur powder is known to stop spore [[germination]]. High standards of [[hygiene]], good soil drainage, and careful watering may minimize problems. Any appearance of rust must be immediately dealt with by removing and burning all affected leaves.{{Citation needed|date=October 2023}} [[Composting]], or leaving infected vegetation on the ground, will spread the disease.{{Citation needed|date=October 2023}}

====Commercial control====
In some large acreage crops, fungicides are applied by air. The process is expensive and fungicide application is best reserved for seasons when foliar diseases are severe. Research indicates, the higher the foliar disease severity, the greater the return from the use of fungicides.<ref>{{cite web|url=http://www.stopsoybeanrust.com/viewStory.asp?StoryID=1140|title=Stopsoybeanrust.com|website=www.stopsoybeanrust.com|access-date=2010-08-06|archive-date=2018-06-12|archive-url=https://web.archive.org/web/20180612143153/http://www.stopsoybeanrust.com/viewStory.asp?StoryID=1140|url-status=live}}</ref> Southern corn rust disease, can be confused with common rust. Southern rust's distinguishing characteristic is that pustules form mostly on the upper leaf surface and spores are more orange in color. Southern rust spreads more quickly and has a higher economic impact when hot, humid weather conditions persist. Timely fungicide applications to control southern rust are more crucial than with common rust.<ref>{{Cite web|url=https://www.channel.com/en-us/agronomy/common-corn-rust.html|title=Common Corn Rust|website=www.channel.com|access-date=2019-12-16|archive-date=2019-12-16|archive-url=https://web.archive.org/web/20191216180933/https://www.channel.com/en-us/agronomy/common-corn-rust.html|url-status=live}}</ref>

A variety of preventative methods can be employed for rust diseases:
* High moisture levels may exacerbate rust disease symptoms. The avoidance of overhead watering at night, using drip irrigation, reducing crop density, and using fans to circulate air flow may decrease disease severity.
* The use of rust-resistant plant varieties
* Crop rotation can break the disease cycle because many rusts are host-specific and do not persist long without their host.
* Inspection of imported plants and cuttings for symptoms. It is important to continually inspect the plants because rust diseases have a latent period (plant has the disease but shows no symptoms).
* Use of disease-free seed can reduce incidence for some rusts<ref name="Marsalis, M. 2006"/>

===Host plants affected===
It is probable that most plant species are affected by some species of rust.{{Citation needed|date=October 2023}} Rusts are often named after a host species that they infect. For example; ''[[Puccinia xanthii]]'' infects the flowering plant cocklebur (''[[Xanthium]]''). Recently, a total of 95 rust fungi belonging to 25 genera associated with 117 forest plant species belonging to 80 host genera under 43 host families were reported from the [[Western Ghats]], [[Kerala]], [[India]].<ref name="How many rust species exist?"/> Rust fungi include:
{{Columns-list|colwidth=25em|
* ''[[Aecidium]]''
* ''[[Cerotelium]]''
* ''[[Chaconia (fungus)|Chaconia]]''
* ''[[Coleosporium]]''
* ''[[Crossopsora]]''
* ''[[Didymopsorella]]''
* ''[[Hamspora]]''
* ''[[Hapalophragmidium]]''
* ''[[Hemileia]]''
* ''[[Kernkampella]]''
* ''[[Kuehneola]]''
* ''[[Kweilingia]]''
* ''[[Macabuna]]''
* ''[[Maravalia]]''
* ''[[Melampsora]]''
* ''[[Olivea]]''
* ''[[Physopella]]''
* ''[[Puccinia]]''
* ''[[Ravenelia]]''
* ''[[Uraecium]]''
* ''[[Uredo]]''
* ''[[Uredopeltis]]''
* ''[[Uromyces]]''
* ''[[Xenostele]]''
* ''[[Zaghouania]]''
}}

Rust infected host genera include:<ref name="How many rust species exist?"/> 
{{Columns-list|colwidth=20em|
* ''[[Acacia]]''
* ''[[Acalypha]]''
* ''[[Ageratina]]''
* ''[[Albizia]]''
* ''[[Arundinaria]]''
* ''[[Bambusa]]''
* ''[[Bidens]]''
* ''[[Blepharis]]''
* ''[[Bombax]]''
* ''[[Bridelia]]''
* ''[[Callicarpa]]''
* ''[[Canarium]]''
* ''[[Canthium]]''
* ''[[Catunaragam]]''
* ''[[Cinnamomum]]''
* ''[[Cissus]]''
* ''[[Cleistanthus]]''
* ''[[Clerodendron]]''
* ''[[Coffea]]''
* ''[[Coix]]''
* ''[[Cosmostigma]]''
* ''[[Crotalaria]]''
* ''[[Dalbergia]]''
* ''[[Dendrocalamus]]''
* ''[[Derris]]''
* ''[[Diospyros]]''
* ''[[Dipterocanthus]]''
* ''[[Elaeagnus]]''
* ''[[Elephantopus]]''
* ''[[Elettaria]]''
* ''[[Eragrostis]]''
* ''[[Euphorbia]]''
* ''[[Ficus]]''
* ''[[Flacourtia]]''
* ''[[Grewia]]''
* ''[[Holarrhena]]''
* ''[[Holoptelia]]''
* ''[[Hypericum]]''
* ''[[Ichnocarpus]]''
* ''[[Ischaemum]]''
* ''[[Jasminum]]''
* ''[[Justicia (plant)|Justicia]]''
* ''[[Loesneriella]]''
* ''[[Luvunga]]''
* ''[[Meiogyne]]''
* ''[[Meliosma]]''
* ''[[Mimusops]]''
* ''[[Morus (plant)|Morus]]''
* ''[[Neolitzea]]''
* ''[[Ocimum]]''
* ''[[Olea]]''
* ''[[Oxalis]]''
* ''[[Pavetta]]''
* ''[[Persicaria]]''
* ''[[Phyllanthus]]''
* ''[[Plectranthus]]''
* ''[[Plumeria]]''
* ''[[Pongamia]]''
* ''[[Premna]]''
* ''[[Protasparagus]]''
* ''[[Rubus]]''
* ''[[Salix]]''
* ''[[Spondia]]''
* ''[[Strobilanthes]]''
* ''[[Strychnos]]''
* ''[[Tabernaemontana]]''
* ''[[Terminalia (plant)|Terminalia]]''
* ''[[Toddalia]]''
* ''[[Trichosanthes]]''
* ''[[Vernonia]]''
* ''[[Vigna]]''
* ''[[Wrightia]]''
* ''[[Xanthophyllum]]''
* ''[[Xylia]]''
* ''[[Ziziphus]]''
}}

Some of the better known hosts include:
{{Columns-list|colwidth=30em|
*''[[Arisaema triphyllum]]'', Jack-in-the-pulpit
*''Avena sativa'', [[Oat]]s
*''[[Berberis vulgaris]]'', Common barberry
*''[[Vicia faba]]'' - Broad beans
*''[[Coffea arabica]]'' - Coffee
*''[[Crataegus monogyna]]'' - Hawthorn
*[[Chrysanthemum]]
*''[[Quince|Cydonia]]'' - Quince
*''[[Euphorbia maculata]]'', Spotted Spurge
*''[[Fuchsia]] spp'', 
*[[Garlic]]
*''Hordeum vulgare'', [[Barley]]
*''Juniperus virginiana'', [[Juniperus virginiana|Red Cedar]] (Juniper apple disease)
*''[[Juniperus communis]]'' - Juniper
*''[[Allium ampeloprasum]]'' - Leek
*''[[Malus]]'' – Apple
*''[[Mentha piperita]]'' - Peppermint
*''[[Mespilus]]'' - Medlar
*[[Onion]]
*''[[Pelargonium]]''
*''[[Primula veris]]''
*''[[Primula vulgaris]]''
*''[[Pyrus]]'' - Pear
*''Rosa spp'', Roses
*''Triticum spp.'', [[Wheat]]
*''Oxalis spp.'', [[Oxalis]]
*''Secale cereale'', [[Rye]]
*''[[Senecio vulgaris]]'' -Common groundsel
*''[[Xanthium canadense]]'' Cocklebur
}}