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Warm season turf has a difficult time in fall and spring making the transition from growing to dormant and back to actively growing again. We often see diseases in turf in spring and fall. Proper disease identification and control practices are important in managing turf disease. Here are some references that can help you with turf disease control.
Turfgrass Diseases in Georgia: Identification and Control - This publication is a comprehensive guide to identifying and controlling turfgrass diseases in Georgia.
Turfgrass Diseases: Quick Reference Guide - For eleven major diseases, this Guide lists:
- Causal agent
- Susceptible turfgrasses
- Conditions promoting disease
- Symptoms and Control
Guide to Turfgrass Fungicides - This publication is a guide to common turfgrass diseases and chemical controls. One of the tools in this publication is a chart on Efficacy of Turfgrass Fungicides which allows turf managers to select the fungicide which best controls each disease.
Abiotic Injuries and Disorders of Turfgrasses in Georgia - Turfgrass stands can be injured and damaged by biotic (living) and abiotic (non-living) agents. Determining whether the condition is caused by a biotic or an abiotic agent can be challenging.
Identification and Control of Spring Dead Spot in Georgia
Ten Steps to a Healthier Home Lawn - The key to disease control is a healthy plant. These management practices will help achieve vigorous, healthy turf and reduce turfgrass disease problems.
Georgia Turf – This website has numerous resources for pest management and culture of all major turf types in Georgia.
Past Landscape Alerts on turf topics – Topics include turf diseases.
Turfgrass Pest Control Recommendations for Professionals – Find pesticide recommendations and other information.
Turfgrass Management Smartphone App - Turfgrass Management is a comprehensive application that contains pictures, information, and recommendations for managing turf weeds, diseases, and insects.
For further information contact your local County Extension Office – (800) ASK-UGA1!
September 9, 2011
In urban areas, mechanical injury is a major cause of shade tree decline. In subdivisions and new housing developments, shade trees are often abused; roots are torn out of the ground, bark is bruised and the soil around trees is disturbed. Losses from such damage could be minimized or even avoided if people realized that trees may not survive such treatment and took precautions to avoid abusing them. Many utilities and municipalities are also guilty of tree abuse. When putting in gas and water lines or paving streets, workers damage or destroy roots which disturbs food production, growth control and the tree's top-root balance. Root loss contributes to the weakening and decline of a tree's crown. As with drought, these symptoms can often be delayed in appearance by 1 to 2 growing seasons.
Some of the worst things you can do to a tree are: add fill around the trunk, cultivate or remove soil from around the trunk, compact the soil (especially when the soil is wet), or damage the bark on the trunk. Each of these events leads to a weaker tree that can lead to other stress factors or pests injuring the tree further.
Chemical damage (pollution/pesticides) of trees is very common. Injury to trees from pollution as well as chemical application by homeowners and commercial applicators, are common occurrences. Pollutants are now a part of our urban and rural environment and ecology. Pollutants, such as ozone, sulphur dioxide, fluorides, sunlight-induced nitrates (PAN), road and sea salts and particulate matter (flyash, dust, cinders), all disrupt the life processes of trees. Some pollutants will be concentrated near roadways and factories that are their source. Other pollutants, like ozone, can disrupt tree growth a hundred miles downwind from a city. Pollution acts as one factor in a tree decline problem.
Chemical injury can be much more severe when trees are already weakened by other factors. The "spray and pray" concept (spraying a chemical and hoping it will control whatever the problem is) should be avoided. Chemicals are not always the answer and may actually create more problems. Good tree management should be practiced first. Use chemicals only as helpers after other management practices have been performed.
- Tree Cankers: Many oak species are lost to Hypoxylon canker, a disease that is common in both urban and rural areas. This disease can be diagnosed by its grayish to brown felt appearance on the bark. Little can be done to control this disease since the fungus is actually growing into the wood of the tree. The removal of infected trees and pruning of infected branches will remove the fungus innoculum from the area. However, pruning will not solve the problem of low tree vigor. Careful management practices performed to increase tree vigor will encourage tree recovery.
- Twig Cankers: There are a number of canker-causing fungi which cause twig dieback in many shade tree species. Most are diseases that take advantage of trees that are in a weakened or declined condition. Prune dead wood and initiate management practices to help the tree recover. Fungicide applications generally provide little protection since tree health is the key to canker disease control.
- Leaf Spots: There are numerous leaf spot fungi which infect leaves and cause foliage loss from many urban shade trees. These diseases occur annually and may actually go unnoticed most of the time. During periods of stress, there may be an excessive amount of defoliation attributable to foliage diseases. Foliage diseases of large urban trees are not known to cause any permanent damage unless defoliation occurs several years in succession. Excessive defoliation often occurs when a tree is in a weakened condition.
- Slime Flux: Slime flux, called wet wood, is considered a disease of unthrifty or old trees. Symptoms of slim flux include oozing of either a white or brown, smelly substance from wounds, pruning scars and trunk crotches. The slime is toxic to the bark and may kill large patches when it stays on the bark for a long time. Rinsing twice a year may minimize the damage, but determine what weakened the tree initially and provide best management practices to improve tree vigor.
Shade tree decline is becoming much more prominent. Being able to recognize conditions which promote decline and taking steps to eliminate stresses before symptoms occur will save many urban shade trees.