Soybean Rust Tyler Stucker

What is it? Soybean Rust also known as Asian soybean rust, is a disease that affects soybeans and other legumes. scientific name (Phakopsora pachyrhizi) common name (Phakopsora meibomiae) Mainly a host in soybeans A fungi caused by two types. Phakopsora pachyrhizi and Phakopsora meibomiae.

Soybean Rust Life Cycle

Environmental/ Management The development of soybean rust is favored by prolonged periods of leaf wetness. Mainly in years that there is a lot of moisture or rainfall and leaves become damp for long periods of time. Temperatures at 46 to 86 degrees Fahrenheit. Mainly periods of cool wet weather during growing seasons is favored by soybean rust.

Stages of Soybean Rust

Symptoms Clinical Signs The most susceptible crop stages are between early flower stage and mid-seed development stages Rust infection begins in the low to mid area and moves up the plant. The first symptoms are small gray spots on the undersides of leaves and along leaf veins durring the flowering stage. The spots increase in size over time and change color from gray, to tan, reddish-brown or black. Lesions caused by the rust fungus enlarge, becoming tan or reddish-brown with a raised appearance. As the plant matures and begins to set pods, rust symptoms can spread rapidly to the middle and upper parts of the plant. Lesions are found on petioles, pods, and stems but are most abundant on leaves

Symptoms Signs

Best IPM Control Fungicides by syngenta such as Bravo and quadris. Provides broad-spectrum disease control Sticks and stays on leaf surface Long-lasting control Highly effective as a preventive fungicide

Reasons for interest - Kentucky produces a lot of soybeans and Have a lot of soybeans back home. - Would like to raise soybeans my own one day. - Beneficial to identify and become familiarized with soybean rust and ways to manage it.

RESOURCES 1) www.invasivespeciesinfo.gov 2) http://nt.ars-grin.gov/taxadescriptions/factsheets/index.cfm?thisapp=Phakopsorapachyrhizi 3)http://www.extension.umn.edu/yardandgarden/YGLNews/images2/rustlifecycle.gif 4) http://extension.missouri.edu/p/G4442

Articles http://naldc.nal.usda.gov/download/42148/PDF http://ehis.ebscohost.com/ehost/pdfviewer/pdfviewer?vid=7&sid=ce67d076-6afe-4e45-9f73-340c8c16facc%40sessionmgr13&hid=101

Evaluation of soybean for resistance to soybean rust Conducted of 5 randomly selected field plots. Examine resistant genotypes to soybean rust. Reaction types assessed. Soybean rust severity and lesions assessed. AUDPC units (Area under disease progress curve)

The infection of soybean leaves during conditions of wetness Experiment providing favorable conditions for soybean rust to occur. Interrupting the wetness process with dry periods. Interruption in wet periods resulted in reduced germination of the disease. Reduction in soybean rust severity Continuous wet conditions promoted the disease and disease eventually overtakes the plant. If dry periods are present it can stunt or stop the growth of the disease.

Continuous wet conditions

Wetness interruption GRAPH B starts to reduce greatly except for the disease that hasn’t germinated yet which will now become germinated but as this process re[eats there will be less and less of disease formation.

Development

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