How To Prevent Pythium In Fall Garden Mums

Fungicide Treatment Options For Pythium
Reports of Pythium resistance to Subdue MAXX have become more prevalent in recent years. Rotate it with labeled fungicides that utilize a different mode of action to slow disease resistance. Always read and follow all pesticide label directions. Pesticides other than those mentioned may also be legal, safe, and effective.

Pythium species are soilborne pathogens that can promote root and basal-stem rots in garden mums. The aggressive species of Pythium aphanidermatum is often associated with garden mums. Disease outbreaks are encouraged by high media temperatures often related to summer production on black groundcover fabrics. Growing mums in areas of poor drainage, with high soluble salts or the presence of other plant stressors, creates optimum conditions for this pathogen to develop and spread quickly.

Know The Symptoms

Symptomatic plants may first exhibit a wet, black-brown basal-stem rot that can extend several inches above the media surface. Examination of the root system will reveal brown, soft roots that, when pulled slightly, will slough off the decayed epidermis and cortex, leaving the inner vascular strand. Once the root system is compromised, affected plants wilt and look dull in color or turn yellow. In the early stages of the disease, plants may wilt during the day but recover somewhat overnight.

Preventive Measures Reduce The Risk Of Root Rot

Manage your crop to minimize the risk of Pythium by using a soilless media that has drains well. High EC (soluble salts) levels in the media can damage the root system, particularly if the media is allowed to dry down. The resulting damage can become an entry point for Pythium. Be conscious of this risk if you feed your crop heavily early in production (300 ppm or more on a constant basis). Monitor the EC and avoid large swings in soil moisture.

Ponding of water in fields provides zoospores, the mobile swimming structures, with ready access to adjacent healthy mum plants. This is an important method of disease spread. Drip- or trickle-irrigation systems greatly reduce the risk of spreading this water-borne pathogen. If overhead watering, look for low-lying areas that collect water. Provide additional drainage, elevate plants out of the standing water, or avoid using these areas.

Utilizing integrated pest management (IPM) practices can reduce the risk of Pythium, but sometimes fungicides are needed. Several microbial fungicides can be used at planting. Examples include Actinovate SP (Streptomyces lydicus WYEC 108), Companion (Bacillus subtilis GB03), and RootShield Plus (Trichoderma harzianum Rifai strain T-22). These products are preventative only. If signs of root disease are evident in the crop at planting, treat with a fungicide that has eradicant properties before applying the microbial fungicide.

Topics: , , ,

Leave a Reply

More From Disease Control...
Growing-Media-Symposium-Tour

November 13, 2017

International Growing Media Symposium Comes to the U.S.

This International Symposium, with representatives from 21 countries, covered new market opportunities, generated innovative ideas, and offered first-hand information to more than 150 attendees.

Read More
Parasitized aphid mummies, ladybird beetle larvae

November 11, 2017

OHP Announces Two New Ornamental Pest Management Tools

OHP recently added two new crop protection tools to its profile of biosolutions: a biological insecticide, and an ornamental fungicide.

Read More
Parisitic Wasp Aphidius colemani

November 7, 2017

Growers Attending Biocontrols East Conference Got a First-Hand Look at Others’ Hands-On Experience

The greenhouse breakout during the Biocontrols East Conference provided real life, hands on experience to attendees, from a grower’s perspective.

Read More
Latest Stories
Researchers Study Rose Varieties

October 17, 2017

Rose Rosette Update: Research into Detection and Manage…

Halfway through a five-year, $4.6 million grant to combat rose rosette disease in the U.S., a national research team is encouraged by the amount of information learned, but admits having a way to go before finding how to overcome the deadly problem.

Read More
Botrytis Symptoms on Leaves

October 17, 2017

How One Grower is Battling Botrytis with a New Biologic…

CropKing in Lodi, OH, recently began using a new beneficial fungus in its fight against Botrytis in its greenhouse tomatoes. So far, the results have been promising.

Read More
BASF Pageant

September 29, 2017

New Fungicide Provides Production and Postharvest Disea…

Pageant TR from BASF controls seven key diseases, and can be used both in the greenhouse and in trucks that are on their way to a retail site.

Read More
Ascochyta in chrysanthemum

September 27, 2017

14 Common Chrysanthemum Diseases to Monitor

Penn State University Extension features a section on its website devoted to diseases commonly found in chrysanthemums.

Read More
Boxwood Blight

September 19, 2017

Concerned About Boxwood Blight? Here Are Some Updated M…

AmericanHort’s Horticultural Research Institute has released an updated version of its boxwood blight Best Management Practices document.

Read More
Powdery mildew on rosemary. Photo credit: SHS Griffin

September 9, 2017

Howler Biological Fungicide from AgBiome Gains EPA Appr…

Howler provides preventive, long-lasting activity on a broad spectrum of soilborne and foliar diseases, with no special handling or storage required.

Read More
Aphids

July 7, 2017

New Tools for Your Crop Protection Arsenal in the Green…

Over the past few months, crop protection companies have developed several new products designed to help you manage a wide range of insect and disease pests. Here’s a look at some of them.

Read More
Primula acaulis, Botrytis, Disease, Griffin Greenhouse Supplies

May 30, 2017

BioWorks Launches New Biofungicide for Botrytis Control

BotryStop was developed for the control of pathogens such as Botrytis, Sclerotinia, and Monilinia in several crops, including ornamentals.

Read More
Botrytis Blight Geranium

May 10, 2017

A Refresher on Botrytis Management in the Greenhouse

When the weather is moist and humid, susceptible greenhouse plants may need to be protected from Botrytis cinerea, a fungus that causes leaf spots, blighting, and stem cankers.

Read More
Downy mildew sporulation on underside of leaf

May 5, 2017

New Bactericide/Fungicide from BioSafe Systems Helps Ma…

BioSafe Systems has introduced PerCarb, a broad-spectrum bactericide/fungicide for use in greenhouse fruits and vegetables, as well as other crops.

Read More
Pythium

March 27, 2017

Florida Ornamental Growers Took a Hit in 2016 Thanks to…

While damage figures from the 2015-2016 winter rains are still being compiled, researchers have found that Phytophthora and Pythium caused severe destruction in many plants.

Read More

March 20, 2017

AgBiome’s New Zio Biofungicide Receives EPA Regis…

The new biofungicide is the first product from AgBiome, and will be marketed by SePRO Corp. in the ornamentals market.

Read More

February 26, 2017

AgBiome Will Enter the Ornamentals Market With a New Bi…

AgBiome, a young company with teammates steeped in decades of experience in the crop protection world, sees an opportunity to bring products to market that fill the existing gaps in plant protection. The company has partnered with SePRO to market and distribute Zio, a biological fungicide expecting EPA registration this spring.

Read More
Tomato Spotted Wilt Virus on Osteospormum

February 23, 2017

4 Pathogens to Prepare For in 2017

Early detection of disease and virus symptoms in the greenhouse is critical. One expert says there are a few pathogens in particular that growers should be monitoring.

Read More
Boxwood Blight

February 7, 2017

Boxwood Blight Detection in Illinois Has Growers on Ale…

Symptoms of boxwood blight, which can spread quickly in production facilities, include leaf spots, stem cankers, and defoliation.

Read More
downy-mildew-impatiens-feature

December 24, 2016

How Agronomic Programs Can Help You Successfully Manage…

To prevent problems before they start, make an agronomic program an essential part of your production plan.

Read More

December 19, 2016

Funding Allocated for Several Horticulture Pest Researc…

The USDA Animal and Plant Health Inspection Service has allocated millions in funding to research plant pests such as boxwood blight, downy mildew, and phytophthora.

Read More
Phytophthora On Poinsettia

November 23, 2016

Tips On How To Prevent Aerial Blight Spread In Poinsett…

According to Michigan State University experts, certain species of the pathogen Phytophthora, which is typically thought of as a root rot, can also cause issues above-ground.

Read More