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Syngenta is committed to working with nursery and greenhouse growers to develop comprehensive solutions to the pest and disease issues they face. These solutions put their innovative products into agronomic and rotational programs that consider modes of action, application methods, preferred timing and application rates.

Agronomic programs offer growers comprehensive, long-lasting management of insects and diseases affecting a specific crop. With a focus on proactive rather than reactive treatments, these programs can help growers save resources by avoiding curative applications.

“Agronomic programs provide a framework for the grower to follow that addresses the primary problems they are likely to encounter when growing a particular crop,” says Nancy Rechcigl, Technical Field Manager, Ornamentals at Syngenta. “It helps to ensure their success by reducing or preventing the problems that would affect the quality and sell-through of the crop.” Having an agronomic program does not eliminate the need for scouting. Monitoring the crop and environmental conditions are still important for proper timing and application of treatments.

A key component of an agronomic program is a well-researched rotation, which serves as a valuable resistance management strategy.

“We take into account the primary insect and disease problems the crop may develop over the course of production. Then we select two to three products with different modes of action that have strong performance and residual activity for each problem. Each product is put in a rotation at a point where it will provide the best benefit,” Rechcigl says. “So the agronomic program is robust and built with a strong resistance management strategy.”

Syngenta introduced many downloadable agronomic programs in early 2017. Through the online resource, GreenCastOnline.com/Solutions, growers can search for and download programs fit for their operation.

Incorporating products with systemic activity and different modes of action reduces the risk of resistance and is key to successfully controlling downy mildew, a potentially devastating disease.
Photo courtesy of Ohio State University

A downy mildew program

Incorporating products with systemic activity and different modes of action reduces the risk of resistance and is key to successfully controlling downy mildew, a potentially devastating disease. A program using Segovis®, Micora® and Subdue Maxx® fungicides delivers long-lasting protection with differing modes of action so that impatiens and other susceptible annuals and perennials can thrive in the garden and remain viable crops in growers’ operations.

In 2016, Fulya Baysal-Gurel, Assistant Professor at Tennessee State University’s Otis Floyd Nursery Research Center in McMinnville, Tenn., conducted a study to evaluate fungicide rotations at 7- or 14-day spray application intervals for the control of downy mildew on roses.

“Rose plants can be latently infected with the downy mildew pathogen,” Baysal-Gurel explains. “When the conducive conditions such as cool weather and high humidity occur for disease development, symptoms may appear overnight. Therefore, preventive fungicide applications in a rotation are critical to control downy mildew.”

The initial fungicide application was Subdue Maxx (2 fl oz/100 gal) and Micora (4 fl oz/100 gal), which was made after observing the first symptoms of downy mildew on Pink Double Knock Out® roses. Next, Mural® fungicide (7 oz/100 gal) and Segovis (2 fl oz/100 gal) were alternated at 7- or 14-day application intervals.

“Fungicide rotation programs at 7- or 14-day application intervals equally and significantly reduced downy mildew incidence as well as the average number of infected leaves compared to the non-treated control,” says Baysal-Gurel. “This study also showed that the 7-day rotation program significantly increased plant height and width compared to the non-treated control plants.”

The strong residual performance and broad-spectrum activity of Mural allows it to be used in a flexible manner depending upon where its strength is needed, Rechcigl says.

“Placing Mural in the rotation with strong, systemic oomycete products, like Segovis and Subdue Maxx, provides comprehensive control of most diseases a grower may encounter on roses,” Rechcigl adds. “Mural provides strong activity on leaf spot diseases, powdery mildew and rusts, and it also has activity on downy mildew diseases.”

Mural also has the benefit of having both translaminar and systemic activity. It can be used as a spray or a drench —depending on the grower’s primary targets or problems.

“Growers may use it as a drench to control root and stem rots such as Rhizoctonia and get the systemic benefit of suppressing powdery mildew on the crop as well,” Rechcigl says.

Drench applications

Baysal-Gurel and her team conducted another study to evaluate systemic fungicide drench applications for the control of downy mildew on roses. Treatments were Segovis (1.0 fl oz/100 gal and 3.0 fl oz/100 gal), Subdue Maxx (2 fl oz/100 gal) and two Syngenta experimental products A13836B (2.75 fl oz/100 gal) and A14658C (20 fl oz/100 gal). Treatments were applied as a drench at the first signs of downy mildew with a volume of 20 fl oz per No. 3 nursery container.

According to Baysal-Gurel, all fungicide treatments “significantly reduced the final severity rating, disease progression, downy mildew incidence, and average number of infected leaves compared to the non-treated control. The severity of downy mildew and disease progression among fungicide-treated plants was significantly lower in plants treated with the higher rate of Segovis.”

She also notes that “all treatments significantly increased the plant height and width compared to the non-treated control. Our drench trial shows the benefit of using systemic products in the treatment program — with one application providing excellent protection for 30 days.”

Segovis is effective in this rotation because of its translaminar and systemic activity, which will likely extend the grower’s treatment interval while maintaining good protection, says Baysal-Gurel.

Syngenta has tested this rotation and many more to ensure their effectiveness in the greenhouse or nursery. By developing these programs, Syngenta can help save growers’ time and resources so they don’t have to spend their time looking for the appropriate product to use and ensuring it controls the insect/disease and is compatible in their operation.

“The programs provide efficiency and economic benefits to the grower. It will help them save time since a comprehensive program is already developed and ready to be implemented, and it has a built-in resistance management strategy as part of the program, which is critically important,” Rechcigl explains. “Being prepared also means growers are less likely to encounter the problems they’re trying to prevent with fewer applications, so quality remains high and shrink and input costs remains low. Curative or corrective treatments often require higher rates and more applications, therefore increasing production costs.”

These agronomic programs have been tested so growers can be confident using them to grow beautifully strong plants that flourish long after they leave the production facility.

©2017 Syngenta. Important: Always read and follow label instructions. Some products may not be registered for sale or use in all states or counties and/or may have state-specific use requirements. Please check with your local extension service to ensure registration status and proper use. GreenCast®, Micora®, Mural®, Segovis®, Subdue Maxx® and the Syngenta logo are trademarks of a Syngenta Group Company. Photos are either the property of Syngenta or used under agreement.