Greenhouse Diseases 101: Rhizoctonia

Rhizoctonia on coleus. Department of Plant Pathology Archive, North Carolina State University, Bugwood.org

Damping-off of is a general term that describes the death of seedlings from fungal disease. There are several fungal organisms that can cause damping off, including Botrytis, Sclerotinia, Alternaria, Pythium and Rhizoctonia. The last two are the most common culprits.

At some point in his or her career, most growers have had the experience of seeing sections of seedling flats turn brown right at the soil line and topple over. This is often an indicative sign of Rhizoctonia (Rhizoctonia solani). Older, sturdier seedlings may die, but are more likely to stay upright.

While some fungi are host-specific, Rhizoctonia does not discriminate, and it can infect practically all herbaceous and woody greenhouse crops. Younger plants are most susceptible. The collapse and death of seedlings, which have brown lesions on the stems right at the soil line, is the most commonly associated sign of Rhizoctonia, but the disease can kill seedlings before they even emerge from the soil. Severely infected seed does not even germinate, or if it does, the newly sprouting roots and stems are killed before they emerge. When Rhizoctonia infects older plants, it causes a brown or black canker at the base of the stem near the soil line. If the canker grows, it eventually interferes with the uptake of water and nutrients and the plant dies. Sometimes Rhizoctonia can be seen on fruit or leaves close to the soil surface because it has spread there by splashing water.  In high humidity, the fungus may grow up the stem from the soil line.

Rhizoctonia survives from year to year by producing sclerotia, which are tiny, irregularly shaped, brownish-black structures that can survive for many years in the soil and on plant matter. It can also survive as a branching, filamentous structure called the mycelium, which also has the ability to persist in soil, at the end of hoses and on tools and containers until conditions are right for infection.

Prevention And Control

Rhizoctonia does not produce spores, so it is spread mainly by water or wind moving infected soil particles. It is also easily spread by human workers who track infected soil on their feet or hands and by diseased cuttings or plants.

Unfortunately, R. solani thrives in normal greenhouse conditions. It doesn’t need high humidity or excessive moisture to thrive, although such conditions will enhance its rapid spread. It favors warmer temperatures, so it is most common in the spring and summer.

As with most greenhouse problems, prevention is key. Purchase disease-free seed from a reputable source. Workers need to strictly observe sanitation guidelines, and greenhouse floors should be kept clean and free of soil and plant debris. Infected plants should be rogued out at the first sign of disease and a protective drench should be applied to the rest of the crop. Preventative fungicidal drenches can be applied to crops that have been found to be commonly affected by Rhizoctonia in the operation in the past.

Sources

Ball, Vick. (Ed.). Ball RedBook. 16th ed. Batavia, IL: Ball Publishing, 1998.

Ceresini, Paulo. Rhizoctonia solani. North Carolina State University. http://www.cals.ncsu.edu/course/pp728/Rhizoctonia/Rhizoctonia.html

Damping-off Disease. Cornell Greenhouse Horticulture. Cornell University. http://www.greenhouse.cornell.edu/pests/pdfs/diseases/RootRots.pdf

Wick, Robert L. 1998. Damping Off of Bedding Plants and Vegetables. University of Massachusetts Amherst. http://extension.umass.edu/floriculture/fact-sheets/damping-bedding-plants-and-vegetables

 

 

Leave a Reply

More From Crop Inputs...
Suzanne Wainwright-Evans

February 8, 2016

Register Now For Biocontrols USA 2016 Workshop

Biocontrol is becoming a mainstream part of growing plants commercially. Every good program starts with quality products and a good supply chain. Register now to join us from 1:00-4:00 p.m. on March 4, following the conclusion of the education program at the Biocontrols USA 2016 Conference & Expo in Monterey, CA for a special event that will help you improve your biocontrols program. In this informative, real-world workshop led by biocontrols expert Suzanne Wainwright-Evans, owner of Buglady Consulting, you’ll learn: The key players that are producing beneficials How to check product quality once you get them The latest trends and practices growers are using to implement beneficials into their programs Important pitfalls to avoid. A roundup of the current biocontrol research that can help you be more successful in your production practices this season. Wainwright-Evans, a pest management specialist, has been involved in the green industry for more than two […]

Read More
Gotham Greens Queens

February 8, 2016

Gotham Greens Opens Newest Greenhouse In Queens, NY

The new facility, which was partially funded by grants based on reduced energy consumption, nearly triples Gotham Greens’ overall production capacity in New York.

Read More
Travis Higginbotham

February 8, 2016

Biocontrols And Next-Generation Production

Biocontrols are becoming much more established in greenhouse production. In some cases, it’s the next generation of growers that’s helping to support the adoption of this next generation of pest control. Travis Higginbotham, R&D Manager for Battlefield Farms, in Rapidan, VA, is a great example. Brought on in 2014, he is helping Battlefield take the next step in product development, as well as become more efficient as a business and adapt to new technologies and demands from their customers with a more proactive approach. Higginbotham will share information on Battlefield’s nematode program at the Biocontrols USA 2016 Conference and Expo, March 3-4, 2016 in Monterey, CA. We asked him about the details involved with building a new biocontrols program, as well as the future of sustainability in greenhouse production. Q: What are the differences in costs involved in using biocontrols? What costs should growers consider, aside from the hard costs […]

Read More
Latest Stories
Suzanne Wainwright-Evans

February 8, 2016

Register Now For Biocontrols USA 2016 Workshop

Biocontrol is becoming a mainstream part of growing plants commercially. Every good program starts with quality products and a good supply chain. Register now to join us from 1:00-4:00 p.m. on March 4, following the conclusion of the education program at the Biocontrols USA 2016 Conference & Expo in Monterey, CA for a special event that will help you improve your biocontrols program. In this informative, real-world workshop led by biocontrols expert Suzanne Wainwright-Evans, owner of Buglady Consulting, you’ll learn: The key players that are producing beneficials How to check product quality once you get them The latest trends and practices growers are using to implement beneficials into their programs Important pitfalls to avoid. A roundup of the current biocontrol research that can help you be more successful in your production practices this season. Wainwright-Evans, a pest management specialist, has been involved in the green industry for more than two […]

Read More
Travis Higginbotham

February 8, 2016

Biocontrols And Next-Generation Production

Biocontrols are becoming much more established in greenhouse production. In some cases, it’s the next generation of growers that’s helping to support the adoption of this next generation of pest control. Travis Higginbotham, R&D Manager for Battlefield Farms, in Rapidan, VA, is a great example. Brought on in 2014, he is helping Battlefield take the next step in product development, as well as become more efficient as a business and adapt to new technologies and demands from their customers with a more proactive approach. Higginbotham will share information on Battlefield’s nematode program at the Biocontrols USA 2016 Conference and Expo, March 3-4, 2016 in Monterey, CA. We asked him about the details involved with building a new biocontrols program, as well as the future of sustainability in greenhouse production. Q: What are the differences in costs involved in using biocontrols? What costs should growers consider, aside from the hard costs […]

Read More
Jim Zablocki, Plant Prod

February 5, 2016

Sign Up For A Webinar On Using Plant Nutrition To Impro…

The webinar takes place March 2, and covers how leading growers are using plant nutrition to minimize costs, reduce the number of factors they need to worry about, and lessen environmental impacts.

Read More
Biocontrols Conference and Expo 2016

February 4, 2016

Biocontrols 2016 Conference Offers Insights And Learnin…

The Biocontrols 2016 Conference & Expo, which takes place March 3-4, 2016, in Monterey, CA, brings together growers, pest control advisers, suppliers, researchers, and other segments of the industry to share the latest information on biochemicals, microbial pesticides, and beneficials, and help you put biocontrols to work in your operation.

Read More
Fertilizer Rates Feature Image

January 29, 2016

Bioworks Releases New Higher Nitrogen Fertilizer For Or…

Verdanta N-Vita 9-4-3 promotes foliar growth and features a slow release process, making nutrients available for a longer period of time.

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

January 19, 2016

EPA Approves Syngenta’s Mural Fungicide For Use On Seve…

Mural contains two active ingredients and is designed to provide broad-spectrum control of a wide range of root and foliar diseases.

Read More

January 12, 2016

EPA Releases Preliminary Risk Assessment For Imidaclopr…

The assessment, which will soon be open for public comment, indicates that imidacloprid potentially poses risk to hives when the pesticide comes in contact with certain crops that attract pollinators.

Read More
Sustane Research Greenhouse 2015

January 7, 2016

Fertilizer Manufacturers Aim To Deliver Sustainable Sol…

Industry experts discuss the latest trends to help ensure 2016 is your best year yet.

Read More
Vestaron

December 30, 2015

Vestaron’s Spear Bioinsecticide No Longer Carries Bee T…

Following a review that shows it has no detrimental effect on honeybees, EPA has removed the bee toxicity warning statement from Spear.

Read More
How To Overcome Downy Mildew Spread On Impatiens

December 16, 2015

Syngenta Launches Two New Fungicides For The Ornamental…

Solatenol and oxathiapiprolin, each with unique active ingredients, should be available to growers in early 2016.

Read More
Biocontrols Conference and Expo 2016

December 15, 2015

Mark Your Calendars For The Second Annual Biocontrols U…

Produced by Meister Media Worldwide in cooperation with the Biopesticide Industry Alliance, the event brings together growers, pest control advisors, researchers, biocontrols suppliers, and everyone who plays a role in this crucial element of integrated pest management programs.

Read More
Gerbera Yellow Sticky Card

December 10, 2015

Michigan State Offers Free Download Of Bulletin Coverin…

The new fact sheet provides photos and lists commercially available beneficial insects, their target insects, and key facts about biocontrol agents.

Read More
Landmark Open-Bottom Tray

December 8, 2015

Landmark Plastic Addresses Retailer Capillary Mat Requi…

With the availability of water being the number one global risk based on its overall impact to society, it’s no surprise that big name retailers like Walmart, The Home Depot and Lowe’s have taken aggressive steps to reduce their water consumption at store level. More specifically, for the Spring 2016 selling season, Walmart has mandated that its horticultural partners be capillary mat compliant. This means that plants typically watered top-down will now be required to be watered through a sophisticated watering mat that helps saturate the plants from the bottom up. To help growers embrace this new requirement, Landmark Plastic has developed a new trade gallon tray with an open bottom that enables plants to be watered from the roots up. This not only helps utilize water more efficiently, but also helps retailers reduce labor costs associated with the task of watering. “We’ve made it our business to solve problems […]

Read More
Arthij van der Veer Feature image

December 7, 2015

Sustainability Is Key To Your Operation’s Future

During Greenhouse Grower's 2015 Top 100 Growers Breakfast at Cultivate'15, Arthij ven der Veer of MPS (More Profitable Sustainability) discussed crop protection trends in Europe, Latin America, and around the world, and what to expect on the horizon.

Read More
Bee Vectoring Technology Bumblebee

December 1, 2015

New Crop Protection Solution Uses Bees To Deliver Bioco…

The new system from Bee Vectoring Technology incorporated a powdered crop protection material into the lid of commercial bumblebee hives. Bees pick up the product when they leave the hive and deposit it on every plant they visit.

Read More
Stockosorb Crystals_with water Agriculture leaf (Evonick)

November 21, 2015

9 Sustainable Growing Media Products For Superior Green…

Manufacturers are delivering new growing media products to help growers attempt to minimize their footprint without sacrificing quality. Here are nine new products to consider for your greenhouse operation.

Read More
Suzanne Wainwright-Evans

November 16, 2015

Real-World Biocontrols Trends From The Buglady

During ,em>Greenhouse Grower's Top 100 Breakfast at Cultivate'15, Suzanne Wainwright-Evans of Buglady Consulting discussed trends in biocontrols, including what she has seen from breeders, growers and even public gardens.

Read More

October 13, 2015

Bayer CropScience And OHP To End Marketing Partnership …

The move allows Bayer to market its ornamental products directly to greenhouses and nurseries, although OHP will still service a limited line of Bayer products.

Read More
[gravityform id="35" title="false" description="false"]