Rust is favored by warm and humid (though dry) conditions and develops most frequently on grasses subject to drought conditions, low nitrogen fertility and shade.
The disease first appears on grass leaves as small orange to reddish-brown flecks that enlarge to form raised spore-masses on leaves and stems. When the spore is disturbed (such as by foot traffic walking through it or mowing the lawn), the spore may burst and leave an orange 'powder' on shoes or mowers. This will not stain and is not toxic. Heavily infested turf becomes thin with an overall yellow-orange to reddish-brown color. Infected leaves turn yellow, wither and die though this disease is rarely severe.
Fungicides are not usually warranted, though if you need a technician to come out and review the condition of your lawn, feel free to contact us at 419-536-4344.