When it comes to controlling the many different types of diseases that your crops may be susceptible to, it’s important to have a comprehensive plan of action to allow you to send the best plants into the market and to conserve your inputs such as chemicals and labor. Dr. Kathie Kalmowitz, Technical Specialist, Turf & Ornamentals at BASF
, outlines what you must consider to create a plan that’ll ensure crop success.
What is an RMP?
A Resistance Management Program (RMP) is a plan that covers all aspects of a disease outbreak in your operation. A successful RMP encompasses everything from prevention – including scouting, sanitation and record keeping – to the use and rotation of products to eradicate disease and decrease the risk of resistance development.
A good RMP also covers fungicides, insecticides and herbicides. “We want growers to look at what they’re trying to control, and then choose products that’ll provide a very high level of control on what is targeted,” Kalmowitz says.
Scouting and record keeping
No matter which crop(s) you’re working with, it’s important to know the history of the crops you’re producing. “This information helps growers develop a spreadsheet or matrix where they know for a fact that as they grow the plant from a rooted cutting or a plug to finish, this crop has the potential to become infected with specific diseases,” Kalmowitz says.
Keeping good records of a crop during scouting is especially helpful when introducing a new variety or plant species into the operation. “If it’s a new crop, note whether or not there is potential for specific disease problems,” she adds.
Additionally, with a new introduction, growers are “opening themselves up to having to deal with new diseases that they may not have had experience with,” Kalmowitz says. Part of what an RMP is, she adds, is knowing how to grow your crops under optimal conditions, including fertility and light levels, overall soil-type mix and more. Following recommendations from the breeder or producer will reduce the crop’s potential to develop disease. “Growing a plant under optimum conditions to be the healthiest it can be is always one of the best ways to manage your crop and hopefully have few pest problems,” she adds.
Start clean, end clean
Prevention methods are always first choice in an RMP, Kalmowitz says. Therefore, preventative treatments and practices are essential. “Disease always takes the host plant, then it takes presence of the pathogen, and then it takes the environment. If you don’t have those three essential elements working together, then you don’t have disease development,” she adds. In addition to growing under optimal conditions, sanitation is another way to prevent the triggering of a disease in your crop.
“Crops that are high risk for disease should be placed on benches in distinct locations where water, spacing, air movement and other environmental conditions can be controlled. Segmenting the crop in such a way also allows for additional scouting, so any disease that does occur can be contained more efficiently,” Kalmowitz says.
If you know a crop will likely be susceptible to a certain disease, you’ll want to make a well-timed preventative application prior to detectible infection, which Kalmowitz says is the best course of action. “You can use a lower rate on the label rate range. Also, you could possibly expect good initial residual from this application.” By keeping plants in early production clean, you have more plants that finish and go to market.
Get a second opinion
If you do end up seeing a disease that you don’t know, you should do two things: You may protect the plants with a broad-spectrum fungicide, however, prior to spraying, you should send a sample to your diagnostic clinic of choice. “As a grower, you should have at least two clinics that you can depend on,” she says. “Choose a place where you know you can either have a one-to-one conversation, or where you can get a diagnosis within 24 to 48 hours. A disease can move through a crop quickly – you might need a rapid turnaround on the diagnosis, so establish your operation with a clinic and diagnostician.”
In addition, by sending a sample to a lab, you may discover that the disease present is extremely specific to only one or two products in the marketplace. “As a result, you’ll have a more focused plan of treatment,” Kalmowitz adds.
Using products as a rescue puts a lot of pressure on the chemistry to control that pathogen. However, if prevention methods fail and a disease does impact your crop, then it’s advantageous to develop a rotation that will bring the problem under control with as little plant loss as possible. If you continue to use a product with poor expected results, you need to examine the use of this product in your operation and your application methods – and get additional help. “Don’t just continue to use that product. Similar to insect or weed control, having three different chemicals with different modes of action is a good rule of thumb for good chemical rotation and a resistance management,” Kalmowitz says. Chemical groups and modes of action are included on product labels, so refer to the label when planning your rotation.
Products that are broad spectrum, like Pageant® Intrinsic® brand fungicide or Orkestra® Intrinsic brand fungicide, are good for your line-up because they have activity on all four major fungal classes important in ornamental programs, Kalmowitz says. However, it is beneficial to have a mix of products because some products have differences in activity on specific host plants and pathogens. Residual control is dependent on the fungicide and the infection pressure, plant stage and all growing conditions. The labels are written with realistic and tested application intervals and are a good guide for growers to follow when making any fungicide application.
She points out that when you’re forced to make those early curative applications, “You must use the higher rate on the label under the rate range, and expect to do a repeat application on a shorter interval. Noting these two points are important to directly help in managing potential resistance to specific pathogens.”
Always read and follow label directions.
Pageant and Intrinsic are registered trademarks, and Orkestra is a trademark of BASF Corporation.
Photo courtesy of BASF