[1] More commonly known as a “rust,” this pathogen typically affects cotton leaves, which can decrease the quality of the boll at time of harvest.

As large percentages of cotton in the United States are resistant to various rust varieties, there is little economic importance to this disease.

[3] Rust lesions can cause leaves or stems to become weak and break or fall off, resulting in decreased photosynthetic ability and extreme difficulty during harvest.

Symptoms on the alternate host grasses are small ovular red/brown (rust colored) powdery lesions, which release uredospores.

Over a period of five to ten days the dikaryotic mycelia formed by the joining of the receptive hyphae and the pycniospore grows through the cotton leaf to produce aecia.

Ideally, periods of 1 inch (25 mm) or more of rain followed by at least 12 hours of high humidity are needed for the disease to develop.

[4] It is the moisture on the leaf surfaces that leads to disease and spore release/germination, so even well drained soils are susceptible to rust outbreaks.

As previously stated, the importance of this disease can be severe, but growers tend to plant resistant varieties in areas where rust has been prevalent.