How Agronomic Programs Can Help You Successfully Manage Pests

How Agronomic Programs Can Help You Successfully Manage Pests

agrinomic-program-for-downy-mildewWhat defines your success? Maybe it’s being recognized for producing a high-quality crop, shipping products on spec and on time, having 10% or less shrink, or perhaps it’s the economic efficiencies you’ve employed at your facility.

No matter how you define success, it does not just happen on its own. A successful growing season is the result of careful planning and preparation for the expected and, to some extent, the unexpected. One way you can prepare is by using an agronomic program as part of your overall production plan.


An agronomic program is a comprehensive plan that focuses on preventively treating the diseases and insects a crop may encounter. In addition to insecticides and fungicides, it can include nutritional requirements, as well. An important feature of a well-researched agronomic program is that it includes a built-in resistance management strategy that incorporates three or more products with different modes of action. Rotating different modes of action is particularly crucial in the ornamental industry, where production can occur 52 weeks of the year and resistance can become an issue.

Agronomic programs take a preventive approach to disease and insect control. By applying early, before infestations develop, you can save time and resources. Curative applications are not always successful and can require more product and higher costs. Staying ahead of the problem can be the key to preventing them and ensuring the production of a high-quality crop.

The Case Of Downy Mildew

In 2011, reports of downy mildew on impatiens hit the news. Under the right environmental conditions, it reduced healthy plants to mere sticks within weeks. It had a major impact on the ornamental industry, with sales and production of impatiens dropping more than 50%. Several years later, the impatiens market is still struggling to recover.

In addition to impatiens, downy mildew can infect a wide array of woody and herbaceous ornamentals, such as alyssum, coleus, basil, buddleia, phlox, rose, rudbeckia, salvia, snapdragon, and viburnum. It invades production areas through the movement of contaminated seed, infected plant material, or from wind-blown spores. In some crops, the disease causes severe defoliation, resulting in plants with sparse foliage, few flowers, and low vigor.

Rotate For Comprehensive Control

An agronomic program can help prepare you for unexpected outbreaks in your greenhouse or nursery, whether it be insects or diseases like downy mildew. A well-structured program will consider how best to utilize the strengths of different products and leverage modes of action when they will provide the maximum benefit.

Several agronomic programs have been developed for ornamental crops grown in greenhouses or nurseries that have been thoroughly researched to confirm their performance, including one created by Syngenta for spring bedding plants susceptible to downy mildew. Using a “systemic sandwich” approach, the downy mildew rotation is built on a framework of three or more different modes of action.

thrips-damage-in-impatiensSystemic fungicides with strong residual activity are applied as a drench at the beginning of production after transplant and again at the end prior to shipping to ensure long-lasting performance in the retail market and landscape. Protectant fungicides are applied as sprays in between the systemic treatments to assist with control and resistance management.

Starting with an application of a broad-spectrum, systemic fungicide after transplanting can help not only control downy mildew, but protect against root and stem rots caused by Pythium and Phytophthora. A second systemic fungicide that has different modes of action should be applied prior to shipping to ensure strong plant performance in the landscape.

Recognizing that other diseases may also be problematic during production, a broad-spectrum fungicide can be included for additional protection from diseases such as leaf spots, Botrytis, rusts, and powdery mildew. In addition, since thrips and aphids can pose a threat to these crops in the greenhouse, insecticide treatments are suggested to prevent infestations.

In outdoor nursery production, where drench treatments may be difficult to perform because of plant spacing and acreage, the “systemic sandwich” approach can be achieved with spray treatments. This rotation for nursery operations alternates systemic fungicides with other effective fungicides that have translaminar activity on a 14-day interval.

The Framework For Success

Agronomic programs can be customized to fit the needs of your operation. While the framework of rotating products with different modes of action remains the same, the products and pests they control can change with the season, crop, or location.

Let an agronomic program serve as the framework of your success. There are programs available for many different diseases such as Fusarium, rust, and powdery mildew, and insects such as thrips and aphids.