Column
Rust in Lawns and Seasonal reminders
By John Fulton

[August 11, 2014]  Rust in Lawns - This past week or so, rust has paid us a return visit. As grass growth slows, rust is one of the lawn fungi we are dealing with. Rust appears as an orange or yellowish-orange powder (spores) on grass leaf blades, especially in late summer to early fall when the weather is dry.

Rust typically develops on lawns growing very slowly. Higher temperatures may also contribute to slow growth. Overall, the turf may assume a yellow, red, or brown appearance. A close look will reveal the pustules, which easily rub off on your hand. Rust spores can easily be tracked into homes.

Low fertility (in particular nitrogen) and low water availability slow down turf growth, allowing rust to develop. Seasons with excess rain may have rust outbreaks due to loss of available nitrogen. Cool nights with heavy dew and light, frequent rainfall add to the ideal conditions for rust to develop. Warm, cloudy, humid weather followed by hot, sunny weather also favors rust development on lawns. Kentucky bluegrass, perennial ryegrass, and tall fescue are all affected, depending on cultivars. Rust spreads through air, water, shoes, equipment, and sod. Rust may weaken turf grasses and make them more susceptible to other problems.

Control rust through sound turf management. Begin by choosing a quality blend of turfgrass seed. Resistance to rust can vary according to the race of the disease present. Maintain lawns through sound watering, mowing, and fertilizing. If you are watering, water early in the day so the grass dries quickly. Manage problem thatch. Increase vigor with an early fall nitrogen application, but don't overdo it. Check soil phosphorus and potassium levels through soil testing. Also assure good airflow over the site, and provide light penetration by pruning trees and shrubs in the area near the lawn.

A change in the weather will make rust fade away. Early September is a key time for fertilization. Use something with an even analysis or a winterizing fertilizer. If conditions are dry, irrigation is also needed to increase the growth rate of the lawn. Fungicides are rarely suggested on home lawns for rust control, just focus on the listed cultural practices described above – and it is not recommended to mow the lawn in white tennis shoes, unless you are trying to determine if you have rust.

Reminders

We are at a possible time to control Zimmerman Pine Moth. Zimmerman pine moth is one of those “kind of borers.” It generally affects only severely weakened trees, and goes just under the bark to girdle the cambium layer at a branch whorl. It seems like older Scotch, red, and Austrian pines are favorites when they begin to decline. There are other problems which cause the sap to leak out, and they include diseases and birds. Frequently, the damage from a severe infection of the pine moth leads to the branch, or top, breaking off in a wind storm. Permethrin or bifenthrin would be options to attempt to control the pine moth, and it should be applied as a broadcast spray concentrating on the branch junctions and main trunk with a mid-August timing. 

Keep up with spray programs for apples until shortly before harvest. This will help control the sooty mold which looks like charcoal dust on apples. It does scrub off, but notice I said scrub and not rub. Sooty mold is usually worse on the yellow type apples, or at least more noticeable.

Also, the population of spiders, crickets, and other home invaders has grown by leaps and bounds the past week or so. This means to keep up the foundation treatments to provide a protective barrier against these insects. Permethrin or bifenthrin insecticides are the most commonly used now.

[By JOHN FULTON, COUNTY EXTENSION DIRECTOR SERVING LOGAN, MENARD, AND SANGAMON COUNTIES]