Are bermudagrass decline and take-all root rot the same thing?
Over time, bermudagrass decline and take-all root rot have been mistaken for each other in the turf industry. Bermudagrass decline and take-all root rot have distinct issues that need to be managed differently, especially on ultradwarf bermudagrasses.
Bermudagrass decline isn't caused by a single pathogen; it’s a complex of physiological stresses and a variety of pathogens. Anyone who’s grown creeping bentgrass in the transition zone is familiar with summer bentgrass decline – the combined effect of high temperature and humidity with stress-related pathogens like anthracnose, Pythium and algae. Bermudagrass decline is a similar phenomenon. Cool temperatures, cloudy weather, extremely close mowing and other stresses create a plant that is highly susceptible to a variety of pathogens, including take-all root rot, leaf spot, Pythium species and nematodes, which speed up the decline of the stressed turf or kill it outright.
Even though bermudagrass decline is not a disease, routine fungicide applications are an important part of the solution. Many of the contributing factors (weather conditions, event schedules, golfer expectations and water quality, to name a few) are out of the superintendents’ control, but a comprehensive agronomic program to protect the stressed turf can help to maintain acceptable turf quality. Broad-spectrum fungicides or tank-mixtures, such as Briskway® fungicide or Daconil® Action™ + Appear® fungicides, are key components of an agronomic program and have been shown to prevent bermudagrass decline in university research trials.
The fungus Gaeumannomyces graminis var. graminis is a common contributor to bermudagrass decline, but it is also a bonafide pathogen causing take-all root rot even in the absence of stress. Gaeumannomyces graminis var. graminis is a hot-weather fungus, but most infection occurs from late summer to spring when it has a competitive advantage over slowly-growing bermudagrass roots. Combination products that contain azoxystrobin, such as Heritage® Action™, Briskway and Headway® fungicides, are key applications during this time to protect bermudagrass roots from infection by this fungus.
Syngenta agronomic programs for bermudagrass putting greens are designed to prevent both bermudagrass decline and take-all root rot. Many of the applications from late summer through spring are targeted to prevent take-all root rot and the variety of pathogens that contribute to bermudagrass decline. These programs have been shown to improve the winter quality and spring green-up of bermudagrass putting greens.
For more information about agronomic programs from Syngenta, visit GreenCastOnline.com/Programs. You can also download the GreenCast® Turf App for both Apple® and Android® smartphones and tablets to help streamline the tank-mixing calculation and record-keeping process.
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