You Are Here: Management Updates 1998 Archive September 15, 1998

Date: September 15, 1998
Category: Diseases
Subject: Drought Conditions, Anthracnose, Rust

The drought conditions continue to minimize most disease problems. Many golf courses are experiencing stress and drought dormancy on fairways with excess thatch. Irrigation has difficulty keeping such areas watered sufficiently. Several call have asked about small translucent worms in the thatch. These are not the plant parasitic nematodes that cause turf problems which are aquatic (must swim in water) and too small to be seen in turf. In addition, the appoaching cold weather will reduce nematode populations naturally. Anthracnose continues to be reported following core aeration, mostly on annual bluegrass (Poa annua). It may be best to overseed thinned and weakened areas with bentgrass at this time of year and given the relatively dry weather.

Rust is prominent in many lawns. Rust outbreaks are associated with humid conditions that help maintain moisture on leaf blades, but growing conditions that slow plant growth (drought, low fertility, compaction). Rust infections should be mowed away before the powdery orange spores appear under optimal conditions. Where rust is severe enough to cause yellowing of the leaf blades, a fungicide may help reduce infections. If the grass is still relatively green, improvement in cultural practices will probably be sufficient. This will help the plants go into the winter in a healthy state.

- Submitted by: Dr. Gail Schumann