By Chris Kick and Alison Robertson
Crop farmers do not yet have a crystal ball for predicting the kinds of disease pressure they will face during the growing season, but they do have the National Predictive Modeling Tool Initiative, also known as NPMTI.
This multi-year project uses plant disease data and pathogen spore counts collected from farms in the Midwest to develop research-based data that will help forecast incidences of diseases and mycotoxins that affect crops grown in the United States.
Supported by the U.S. Department of Agriculture’s Agricultural Risk Service, the program relies on samples of pathogen spores that are sent to designated laboratories for testing, and disease severity data from field trials in 10 states, to develop disease prediction models that are used to inform U.S. growers.
Alison Robertson, professor in plant pathology and microbiology and extension specialist at Iowa State University, will demonstrate how the tool works at the Farm Progress Show Aug. 27-29 near Boone.
She will have spore traps, as well as petri dishes with live pathogens, and also diseased plants on display in the Iowa State University exhibit. She will explain how spores are collected and counted and disease severity is measured.
Secondly, show attendees will learn how this information is used for predicting the likelihood of disease issues such as tar spot, grey leaf spot and northern corn leaf blight.
Applying fungicide
If plant diseases are expected, farmers can respond by applying fungicide. If no disease is predicted, farmers can skip applying fungicide and save time and money.
“Our goal is to develop disease prediction tools that enable farmers to farm more sustainably, by predicting the kinds of diseases they will face, and giving them more clarity on whether a fungicide is going to be necessary,” she said.
The information is currently available for tar spot. There is an app available called the “Tarspotter,” which uses GPS coordinates to determine if weather has been favorable for the development of tar spot during the growing season, in a specific field. Models in the app use temperature, dewpoint, humidity and precipitation to predict favorable conditions for corn growing regions. Farmers can use the app on their cell phones.
The app will soon be available for other diseases of corn such as gray leaf spot, northern corn leaf blight, southern rust, Curvularia leaf spot and vomitoxin. Additional apps are in development for disease prediction in wheat, cotton and pulses.
“These apps can help tell you if your field is at risk for a disease, and if it’s at risk, then you can apply a fungicide. But if there’s no risk of disease, then that $20-30 per acre on a fungicide application is unnecessary,” she said.
The disease triangle
Robertson reminds farmers that just because a particular pathogen is found in the spore traps does not necessarily mean there will be a disease during the growing season.
“You need to have the right climate, a susceptible hybrid, plus the pathogen, to get the disease,” she said. “This is the ‘disease triangle,’ and each side must be present in order to have disease.”
The NPMTI project was established in 2020, and operates under the auspices of USDA-ARS. It is funded by a congressional appropriation. Each year that additional data are entered, the model and the tool become even stronger.
Similar trials are being conducted across the country, making the tool useful for those who farm anywhere in the United States.
In addition to the live disease specimens, Robertson plans to show what plant disease looks like, and she will be working alongside a team of graduate students and specialists who can answer common questions.
“I’m looking forward to being at the show and interacting with producers and anyone else who is interested in what these tools can do,” she said. “We need to get the word out that this national predictive model exists and is improving, so farmers can have the tools they need to manage crop diseases more effectively, efficiently and sustainably.”
The Iowa State University exhibit space can be found at the corner of 7th Street and Central Avenue.
Robertson can be reached at alisonr@iastate.edu or 515-294-6708.
Source : iastate.edu