April 5, 2013
Download: Your Rose Rosette Questions Answered
Are certain rose cultivars more susceptible to rose rosette disease than others? Does the eriophyid mite that vectors the rose rosette disease virus vector any other diseases to other ornamental or ag crops? Within what radius of a nursery does multiflora rose need to be eliminated? Many questions were generated during our Rose Rosette Disease: History, Spread And Prevention webinar. We compiled the answers to the questions asked by attendees during the webinar, answered by Jim Amrine, Jr., Professor Emeritus of Entomology, West Virginia University, and Conard Pyle’s Mike Dobres. Click here to download the Q&A from the webinar in PDF format. .
April 1, 2013
Greenhouse Diseases 101: Rhizoctonia
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 […]
March 19, 2013
Greenhouse Diseases: Phytophthora
Phytophthora is a serious disease of floriculture crops, and it is especially difficult to control once it has become established. It is one of several organisms that cause root and crown rots. Phytophthora is closely related to Pythium, which also causes root rot. While there are a wide variety of plants that are susceptible to Phytophthora, some are more likely to be infected than others. Poinsettia, rhododendron (azalea), fuchsia, vinca, gloxinia, lantana, African violet, begonia and ornamental peppers are among the more common hosts of the disease. There are several species of Phytophthora, and they are host-specific, meaning each species will only affect certain types of plants. Symptoms To Watch ForInfected plants will display symptoms of wilting and overall decline, including dark lesions, known as cankers, at the crown of the plant. The cankers impede the flow of water and nutrients between the roots and leaves. When they become large […]
March 19, 2013
Four Sources Of Diseases In Vegetable Bedding Plants
How do vegetable seedlings get diseases? Review the four common sources of pathogens in vegetable seedlings – contamination, seed, air currents and insects – and quick tips for managing diseases in this episode of FloriCAST.
February 27, 2013
Greenhouse Diseases 101: Chrysanthemum White Rust
Chrysanthemum white rust (CWR), caused by the fungus Puccinia horiana, is a serious disease with the potential to cause widespread damage both within the greenhouse and to the North American floriculture industry at large if it becomes established on this continent. It originated in China and Japan, but has spread to most other continents, including Europe, Australia, South America and Africa. So far, only isolated cases have been reported in the North America, and aggressive control methods have so far kept the disease from becoming established. Federal quarantine restrictions (six months post-entry) apply to all imported chrysanthemum cuttings, and importation of cuttings from infested countries is prohibited. Disease SymptomsThe first sign of the disease is small white or yellowish spots on the upper leaf surface. Over time, the spots turn brown and may appear sunken. If the leaf is turned over, fuzzy-looking pustules are visible directly underneath the spots. They […]
February 4, 2013
Keep Plants Healthy With These 7 Products
Micora Fungicide GreenCastOnline.com/micora Micora fungicide from Syngenta provides long-lasting preventive protection on foliar, stem and root diseases caused by downy mildew fungi and Phytophthora spp., including P. ramorum and curative control when applied one to two days after infection. Micora provides outstanding preventive protection and control at low-use rates, and it has no negative effects on beneficial insects, making it an ideal tool for integrated crop management programs. It is labeled for use on ornamental crops as well as certain vegetables grown for resale as transplants.
February 4, 2013
Reducing The Spread Of Rose Rosette Disease
The recent release of new hybrid landscape roses, including the Flower Carpet and Knock Out series, has raised interest in these ornamental plants for growers, landscapers and homeowners. According to the USDA-National Agricultural Statistics Service’s Nursery Crops 2006 Summary, deciduous shrubs, including roses, accounted for $648 million in gross sales. Deciduous shrubs were the second largest contributor to sales — behind broadleaf evergreens with sales of $839 million — and accounted for 14 percent of the nursery sales total. But as breeders continue to develop rose varieties that are more disease resistant and easier to grow, one disease continues to elude their efforts to hybridize resistant varieties: rose rosette disease. Symptoms Vary Based On Rose Species, Cultivar Although symptoms of this disease were seen as early as the 1940s, the cause of rose rosette was not reported until 2011. Researchers at the University of Arkansas identified a negative-sense RNA virus […]
January 7, 2013
Schmidt Brothers’ Strategy For Dealing With Impatiens Downy Mildew
From being vigilant about disease control to ramping up production of alternative varieties, listen to Mike Schmidt talk about how Schmidt Brothers will deal with downy mildew on impatiens in 2013.
January 1, 2013
To Grow Or Not To Grow
Despite well-documented cases of impatiens downy mildew, impatiens still tops the list of bedding plants in terms of flats sold. Based on the 2011 Floriculture Crops Summary, 8,353,000 flats were sold in the USDA’s 15-state sample. In the potted plants category, impatiens are in fifth place behind vegetative geraniums, pansies, petunias and seed geraniums (in that order). They’re fourth in quantity sold among annual bedding plants in hanging baskets after petunias, vegetative geraniums and New Guinea impatiens. Impatiens walleriana is clearly still a mainstay crop for many growers. The dilemma that many face is what to do this season. In general, consumers are not very aware of the disease and will still be expecting to purchase impatiens this spring. Many retailers are aware, and some still want to provide what their customers are looking for. Landscapers in affected states will probably stay away from impatiens, since damage is most severe […]
December 12, 2012
OHP Launches Marengo Ornamental Herbicide
OHP Inc. announces the introduction of Marengo Herbicide to growers in the production ornamental market. Marengo has received its federal EPA registration and is undergoing the state registration process. Marengo, with the exciting new active ingredient indaziflam, is a selective pre-emergent herbicide that offers long-term residual control of both grassy and broadleaf leaves. “We are thrilled to add Marengo to our expanding herbicide portfolio,” says Dan Stahl, OHP vice president of marketing and business development. “Marengo offers unparalleled residual control of many hard-to-control weeds with impressive plant safety.” Marengo contains the first active ingredient from Mode of Action Group 29. The active ingredient prevents weed seed germination by inhibiting cellulose biosynthesis. Marengo does not move once applied to the soil and does not volatilize. Marengo is registered for use on production ornamentals grown in outdoor nurseries, as well as on conifers, Christmas trees and ornamental production sites and hardscapes. Marengo […]
December 3, 2012
Everything You Need To Know About Impatiens Downy Mildew
Editor’s Note: This article was written with the assistance of Ball Horticultural Company’s “Grower Guidelines” on Impatiens Downy Mildew and plant pathologist Dr. Colleen Warfield. For the most recent version of grower and retail guidelines, visit www.ballseed.com. Impatiens downy mildew is a destructive foliar disease of Impatiens walleriana that is capable of causing complete defoliation or plant collapse, especially in landscape plantings under moist conditions and cool nights. While there have been sporadic reports of impatiens downy mildew in U.S. greenhouses since 2004, it was not until the summer of 2011 that regional outbreaks of this disease were seen for the first time in landscape beds and container plantings in North America. In early January 2012, outbreaks of impatiens downy mildew were observed in landscape beds and greenhouses in south Florida. It is unclear whether this was a continuation of the 2011 outbreaks or a new cycle of disease for […]