Remarkable leaders have great faith in their vision and their employees. Greenhouse and nursery leaders unselfishly share ideas, trials and successes for the betterment of the entire industry. Now in its second year, the 2018 Horticultural Industries Leadership Awards (HILA) are honoring six recipients who embody these traits. Greenhouse Management, Nursery Management and Syngenta congratulate these extraordinary men and women who represent the green industry with creativity and compassion.
Protecting plants during propagation can be a challenge. Unrooted cuttings and young seedlings generally require warm temperatures, along with frequent misting or high humidity, so they can root into the planting media. However, this warm, humid environment also provides optimal conditions for spores of pathogenic agents to germinate, invading wounds and tender plant tissue.
Plants in propagation can be at risk of developing various diseases, including foliar blights caused by Botrytis cinerea, leaf spots caused by Alternaria, Colletotrichum and Myrothecium spp., as well as lower stem rots. Young seedlings are also at risk of damping-off from Pythium, Phytophthora and Rhizoctonia spp. when the growing media is wet for a prolonged period of time.
“It’s crucial to identify diseases early during propagation,” says Nancy Rechcigl, technical services manager for ornamentals at Syngenta. “Proper cultural practices and preventive fungicide applications can help growers keep a successful crop throughout production. If preventive strategies are not put in place, growers may have to resort to curative applications, which are costly and not as successful.”
Start strong. Stay protected.
Mural® fungicide is a broad-spectrum option for greenhouse and nursery growers to combat these destructive diseases during propagation. It is labeled to control more than 50 ornamental diseases, including Botrytis, leaf spots, rusts, powdery mildew and many soil-borne diseases. Mural offers the flexibility for use as a spray or a drench, providing effective disease protection in propagation and after transplant.
Mural contains two active ingredients, both of which have unique characteristics and benefits that can protect young plants.
“Resistance can be a concern when it comes to fungicides. Rotating modes of action has become more important than ever to treat diseases,” says Rechcigl. “With two active ingredients in FRAC groups 7 and 11, Mural is ideal for incorporating into rotation programs for protection against a wide variety of pathogens.”
One of the two active ingredients in Mural, azoxystrobin, is in the strobilurin class of chemistry, which also provides plant health benefits. Azoxystrobin is systemic and offers xylem mobile movement, meaning it is absorbed by the plant and translocated upward to protect new growth.
Mural also contains Solatenol® fungicide, an advanced generation SDHI (succinate dehydrogenase inhibitor) that binds to the waxy layer of plants and slowly penetrates the tissue, creating a barrier of protection. Mural inhibits spore germination and mycelial growth, providing plant protection inside and out.
In addition to its fungicide activity, azoxystrobin affects physiological processes within plants that result in plant health benefits. Strobilurin fungicides have been shown to:
Lower rates of transpiration in plants, maximizing the efficiency of water use.
Reduce ethylene production, which helps delay senescence, so leaves stay greener longer, resulting in more efficient photosynthesis. This leads to increased production of carbohydrates within the plant, which improves growth and plant vigor.
Increase nitrate reductase levels in plants, allowing nitrates to be more readily available for the production of proteins essential to plant growth.
“Plant health effects, such as root enhancement, are more often seen at lower use rates with strobilurin chemistries. The higher the use rate, the less likely root benefits will be observed,” says Rechcigl. “Mural is labeled at a rate of 4 oz. for foliar and 2-3 oz. for drench applications. At these low rates, it provides broad-spectrum disease control and offers plant health benefits, like increased root density.”
Improved root development has been observed when Mural is applied as a drench to protect plants from root and stem diseases caused by Rhizoctonia solani, Sclerotium rolfsii and Pythium spp. These benefits are due to positive effects on plant physiology, which can vary according to plant species and growing environment.
Recent trials conducted at Ohio State and Michigan State Universities have shown that Mural is providing effective protection against black root rot (Thielaviopsis basicola),which can affect a wide range of annual and perennial crops. Plant development and quality are severely reduced once this pathogen invades and establishes in a root system that is left unprotected. Additional trials are being conducted this year to further assess the activity of Mural on this pathogen.
By applying a fungicide drench of Mural during propagation, you can help prevent the onset of diseases while also experiencing the plant health benefits of its strobilurin chemistry.
Left: Untreated vinca, Right: 2 oz. Mural drench, 24 days after inoculation 2014 VBRC
Mural is labeled for use in greenhouse and nurseries and can be applied to vegetable transplants grown for resale to consumers. Its broad-spectrum activity and two active ingredients make it a powerful option for fungicide rotation programs to help keep crops clean.
Syngenta does not recommend or endorse making applications solely for physiological benefits or using reduced rates (lower than labeled) for physiological effects.
Rotation programs are key components of any operation’s disease management strategy. Resistance remains a concern for growers, and multiple modes of action are needed at times to successfully prevent the spread of diseases.
“Pathogen resistance to fungicides is well known, and the performance of many fungicides has been affected to some degree by pathogens developing resistance,” says Dr. Fulya Baysal-Gurel, research assistant professor at the Otis L. Floyd Nursery Research Center at Tennessee State University. “Using different mode of action fungicides in a rotation program is important due to the risk of resistance development.”
Preventing powdery mildew
Powdery mildew is a common disease that can affect a wide range of herbaceous and woody ornamental crops. Several different fungi cause powdery mildew and each prefers different plants, so preventing the disease early is crucial to prevent it from spreading.
“Powdery mildew may cause cosmetic damage that results in reddish-brown patches, reduce growth by attacking tender shoots and leaf surfaces, and cause premature defoliation,” says Baysal-Gurel. “The disease spreads very quickly, with masses of conidia produced from each new infection. Preventive fungicide applications in a rotation are critical to control powdery mildew.”
Baysal-Gurel conducted several trials evaluating rotations of Mural®, Palladium® and Concert® II fungicides at 14- or 21-day spray application intervals for control of powdery mildew on dogwood and crape myrtle.
The initial fungicide application of Mural (7 oz./100 gal.) was made after observing the first symptoms of powdery mildew disease. Then, Palladium (6 oz./100 gal.) and Concert® II (35 fl. oz./100 gal.) fungicides were alternated on 14- and 21-day application intervals.
When controlling downy mildew, apply systemic fungicides as drenches at transplant and prior to shipping, and other fungicides with different modes of action and contact or translaminar activity as sprays in between to prevent resistance.
“The fungicide rotation program and both spray intervals significantly reduced powdery mildew severity and disease progress compared to the non-treated control in flowering dogwood, as well as on both cultivars of crape myrtle,” says Baysal-Gurel. “This study also showed that the rotation program significantly increased plant height compared to the non-treated control.”
“Securing reliable disease protection with a robust rotation that can be applied on an extended spray interval provides many advantages for the nursery,” says Nancy Rechcigl, technical services manager for ornamentals at Syngenta. “Selecting the proper fungicides to use in a rotation program is very important. Mural, Palladium and Concert II are not only proven to control powdery mildew, but can be used to control leaf spots and rusts as well.”
Rechcigl notes that Mural offers contact, translaminar and systemic activity, which allows it to have both protective and curative properties.
“As a foliar spray, Mural provides protection by inhibiting spore germination and penetration on the plant surface,” says Rechcigl. “Its translaminar and systemic properties allow it to penetrate and move throughout the tissue, stopping the growth of mycelium internally within the plant. This provides an advantage when battling difficult diseases like rust or powdery mildew.”
Powdery mildew is a disease that is most likely to develop in the early summer or fall, when temperatures are warm, relative humidity levels are 70 percent or greater and rains are less frequent. It is important to be aware of these conducive environmental conditions, as they can signal the ideal time to begin a preventive strategy.
“By incorporating products with both translaminar and systemic activity, like Mural, in your rotation with other protectant fungicides, you can likely extend your treatment interval while maintaining good protection,” says Baysal-Gurel.
Taking down downy mildew
Systemic fungicides can also be beneficial when combatting a disease like downy mildew.
“Downy mildew is hard to control for so many reasons – it is very often a systemic disease, not just a matter of leaf spots,” says Margery Daughtrey, senior extension associate at Long Island Horticultural Research and Extension Center at Cornell University. “It can establish during propagation and be passed on through the production chain. It can be carried on seed sometimes and cuttings all the time. Some downy mildew oospores linger in the soil for years and produce new epidemics when healthy plants are placed into contaminated flower beds.”
Dr. Mary Hausbeck, university distinguished professor and extension specialist at Michigan State University, recommends fungicide programs for a disease like downy mildew, particularly on impatiens.
“The fungicides available today can be very helpful in keeping impatiens healthy,” says Hausbeck. “It is important for greenhouse growers to adhere to the fungicide program so if the impatiens are planted into a landscape site contaminated with the downy mildew pathogen, the plant will remain protected.”
Rechcigl recommends a “systemic sandwich” approach to controlling downy mildew. This entails applying systemic fungicides as drenches at transplant and prior to shipping, and other fungicides with different modes of action and contact or translaminar activity as sprays in between to prevent resistance.
“The use of systemic products as a drench prior to shipping provides extended protection in the landscape for the consumer,” says Rechcigl. “This is critically important for the ornamental industry as a whole. If impatiens do not perform well in the landscape for the season, consumers will not want to purchase them in the future. We saw this occur several years ago when the disease was becoming more prevalent across the U.S.”
“Systemic fungicides often protect a plant very thoroughly because they are redistributed within the plant and are not as subject to variations in spray coverage,” says Daughtrey. “Using some systemics and some contact materials in a rotation is often wise. With impatiens downy mildew, in particular, it seems wise to use a thoroughly systemic, long-lasting fungicide as the last treatment before the plant material goes out for retail sale.”
To help provide a solution, Syngenta launched Segovis® fungicide in 2016. It provides a unique mode of action with systemic activity for long-lasting control of downy mildew. Segovis can help growers diversify their rotation programs while also mitigating resistance concerns.
“I’ve tested the active ingredient in Segovis across different downy mildews and it is a highly effective fungicide,” says Hausbeck. “I would certainly call it a ‘stand-out’ for downy mildew control. It’s a wonderful tool for greenhouse growers and provides a unique mode of action against downy mildews.”
Differentiated products can be crucial for greenhouse and nursery growers. With continued innovation occurring in the industry, there are newer, unique control options available in the fight against tough diseases.
“Others’ experiences have taught me that it is essential to use rotation programs with downy mildew management in greenhouses,” says Daughtrey. “Once a population is resistant to a previously valuable fungicide, the utility of that active ingredient is lost. Rotation preserves the effectiveness of the tools we have to use against downy mildews.”
“When highly effective products are chosen and used in a program that alternates among different modes of action, downy mildew doesn’t stand a chance,” says Hausbeck.
Syngenta has created greenhouse and nursery rotation programs for a wide variety of diseases. They can be downloaded at www.GreenCastOnline.com/Solutions
Photo courtesy of William Fountain, University of Kentucky, Bugwood.org
One of the most common insect pests faced in the nursery and landscape, Japanese beetles are also one of the most problematic to control for many reasons.
“Japanese beetles are very difficult to manage because they just keep coming,” says Dr. Daniel Potter, professor of entomology at the University of Kentucky. “They can fly long distances and are attracted to plants that other beetles have already fed on. You can control them one day, but there are going to be more flying in an hour later.”
Active in most areas of the country from late May through August, Japanese beetles are not picky when it comes to food sources and are known to feed on more than 300 types of plants, trees and shrubs. The beetles will also feed on flowers and fruits.
“If you look at the standard chemistries we’re currently using as sprays for control of Japanese beetles, none provide residual control for more than about 14 days,” says Dr. Carl Redmond, research scientist at the University of Kentucky. “You’re talking about having to reapply materials over their entire flight period, which lasts about two months.”
Among foliage-feeding insects, Potter finds Japanese beetles to be the most important, requiring residual protection because of their insatiable feeding and lengthy flight period.
Acelepryn® insecticide from Syngenta provides as much as four weeks of residual protection from Japanese beetles as a foliar spray.
“We’ve done several Japanese beetle trials looking at dosages and different ages of residue in the field. Acelepryn has performed as well or better than any standard out there on the market,” says Redmond. “It is superior in residue length. We’ve gotten control of up to four weeks for Japanese beetles from a single application, which is a major advantage.”
Targeted control
Acelepryn is also labeled for control of caterpillars, including eastern tent caterpillars, fall webworm and bagworms, and sawfly larvae. It offers a unique mode of action to help mitigate resistance concerns.
Neonicotinoids and pyrethroids have long been used to combat insect pests on trees and shrubs, but concerns about their potential hazard to bees have resulted in label restrictions on those types of products.
“The active ingredient of Acelepryn is chlorantraniliprole in IRAC group 28,” says Nancy Rechcigl, technical services manager for ornamentals at Syngenta. “It is a unique class of chemistry that offers an alternative for those looking for newer chemistries to add to their programs.”
Acelepryn has no signal word on the label and is registered as reduced-risk by the U.S. EPA under its Reduced Risk Program. Its active ingredient is target-selective, providing control of leaf-chewing insect pests without affecting beneficial insects such as bees and biological control agents.
“Acelepryn is unique in that foliar sprays will provide extended protection from a broad range of leaf-chewing pests with very low hazard to bees,” says Potter. “In our experiments, we have evaluated Acelepryn in real-use outdoor scenarios and have seen no impact on bees. The product is also quite compatible with biological control.”
In addition to its favorable environmental profile, Acelepryn offers a four-hour REI and requires minimal personal protective equipment. Its long residual activity also leads to fewer applications, saving time and resources for applicators.
Left: Stewartia sprayed with Acelepryn; Right: Untreated Stewartia with Japanese beetle damage. 2015 – Gill, U of MD
Product flexibility
Acelepryn can be used in commercial and residential landscapes. It can be applied to ornamental plants, trees, shrubs, bulbs and Christmas trees.
The product can be sprayed directly on leaves to control chewing insect pests, or as a bark application to ward off pests like clearwing borers.
When applied as a foliar spray, the leaves of plants are protected from Japanese beetles and lepidopteran pests. Acelepryn does not show strong contact activity, but once the treated leaves are ingested by pests, mortality will occur.
“Acelepryn should be applied before infestations reach damaging levels, especially on larger plants,” says Rechcigl. “Curative applications are often not successful with pests like Japanese beetles because they can very quickly cause damage and spread.”
A unique innovation
Acelepryn provides a unique tool for combatting Japanese beetles, caterpillars, and sawfly larvae on trees and shrubs. It has a novel active ingredient that provides excellent pest control while also demonstrating very low hazard to both humans and beneficial insects.
“The combination of strong efficacy, long residual as a foliar spray and very low hazard to non-target organisms is a unique combination,” says Potter. “Acelepryn controls a lot of important chewing pests, gives you the flexibility of not having to apply it over and over again, and provides a very favorable environmental and hazard safety profile.”
Federal registration of Acelepryn for use in nurseries and greenhouses is expected in summer 2018.
As the horticultural market continues to innovate and evolve, insects and diseases remain an ongoing challenge. We are continually impressed by the commitment of growers to maintain clean, pest-free growing environments and are proud to be part of this unique industry.
We are honored to partner with Greenhouse Management and Nursery Management once again to recognize the extraordinary individuals who have made substantial achievements in the horticulture industry. Congratulations to the Class of 2018 Horticultural Industries Leadership Award winners: Nancy Buley, J. Frank Schmidt & Son Co.; Barbara Jeffery-Gibson, Jeffery’s Greenhouses; Jim Monroe, Greenbrier Nurseries; Amy Morris, N.G. Heimos Greenhouse/Millstadt Young Plants; Peter Orum, Midwest Groundcovers; and John Hoffman, Hoffman Nursery.
These recipients have demonstrated exceptional leadership and commitment, and have positively impacted customers, businesses and the industry as a whole.
Syngenta remains committed to partnering with you to help you grow your success. Earlier this year, we introduced Advion® fire ant bait to the nursery market, providing a fast and effective tool for growers with outdoor operations. We continue to offer convenient Multipaks to provide you added value and the opportunity to purchase broad-spectrum products in one convenient package.
Our broad portfolio of plant protection products is designed to offer greenhouse and nursery growers efficient, proven and effective solutions for insect, disease and shelf-life management. We’re proud of the innovative brands you have come to know and trust, such as Mainspring® GNL insecticide and Mural® and Segovis® fungicides, and we continue to invest in research and development for new solutions. One of these new developments, Acelepryn® insecticide, is expected to receive federal registration this summer and will help you better control key pests on ornamental plants, trees and shrubs.
Again, congratulations to the recipients of the 2018 Horticultural Industries Leadership Awards! Thank you for the vital role you play in growing strong, healthy and beautiful plants.
Tripp Trotter Head of Marketing, Turf and Ornamental Syngenta
