Editing Rust (fungus) (section)

====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"/>