NEW ORLEANS—Root, stem and leaf diseases, as well as stressful environmental conditions, are among the constant threats to yield potential—and going “cleaner and greener” can provide much-needed protection.
“We know that with some of the diseases that we have today, like tar spot and other diseases, it can contribute to maybe 60 percent of the corn yield lost in some cases,” said Tyler Harp, insecticide/fungicide technical product manager. Syngenta.
“In 2022, rains and supply chain issues caused delays in planting corn and soybeans. This has made the plants more vulnerable to disease during the early stages of growth and throughout the season. Additionally, much of the United States experienced extreme heat stress during the summer, again making crops more susceptible to abiotic stress.”
How can growers better manage these issues and preserve their yield potential?
Harp: It’s about protecting yield and harvesting on two fronts: cleaner and greener. Cleaner, because it’s free of yield-reducing diseases with a fungicide, and greener, because it’s a sturdier, healthier crop that makes it better able to withstand abiotic stresses like heat and drought.
So, I’m talking about plant health benefits that provide healthier and more productive crops. When using a Syngenta plant health fungicide such as our Miravis brands, a sustained greening effect in the field is often seen.
Even in fields with low disease pressure, plant health benefits, such as greening, can translate into higher yield potential for corn and soybeans. There is the abiotic stress management component which continues to preserve yield.
What have fungicide studies revealed?
Harp: In test plot results in 2020 in a field with less than 5 percent disease severity, untreated soybeans averaged 68.9 bushels per acre, and Miravis Top fungicide-treated soybeans averaged 81.2 bushels per acre. bushels per acre.
Often, the results are really significant yield increases and can add value to the grower and the return on investment could be quite significant.
We know that products like Miravis and Trivapro preserve yields, not only through disease control, but also through the management of abiotic stresses: heat and drought.
What are the benefits of “greener” plants?
Harp: Greener means healthier, more efficient and productive crops and greener leaves provide more light with more light energy. Greener also means more efficient use of water and nutrients.
In addition, Greener provides crop efficiency and quality. It means healthier, higher quality crops, and healthier crops provide a more profitable crop.
All three of these concepts together, working in parallel from the use of a Syngenta plant health fungicide, allow a grower to achieve maximum yields.
What’s the science behind “greener and cleaner?”
Harp: Capturing more light energy through greener leaves. We have conducted some laboratory studies which clearly show that when Adepidin technology, which is one of the components of our Miravis brand, is applied to soybeans under simulated drought conditions, the plants are better able to handle those conditions and continue to have more photochemistry in the leaves.
Photochemistry is the light energy in the leaf that comes from sunlight that allows that leaf to keep producing more energy. Therefore, in the presence of stress the leaves have a more efficient use of energy thanks to the phytosanitary fungicide of Adepidin technology.
Greener plants use water more efficiently. The plant health benefits of Adepidin technology help plants conserve water better by reducing the rate of transpiration while maintaining high levels of photosynthesis.
Do healthier crops have an impact on efficiency and yield?
Harp: Yes, when we compared treated and untreated crops, we know those treated corn plants have healthier stalks. When you have a lot of disease and a lot of abiotic stress, the leaves will pull the starches out of the stem and compromise the integrity of that stem.
So, not only are we getting higher yields in our treated plots versus our untreated plots, but we are also getting less lodging and have healthier stems which allows the combine to move faster through the field and have some harvesting efficiency.
When we set up a few experiments, we showed that fewer lodgings allowed us to go nearly 2 miles per hour faster across the field, a cost savings of $23 per acre.
It’s quite exciting when you think about the value and benefit these products can give the grower not only to protect against yield-reducing diseases, but also to preserve yield in the presence of abiotic stresses such as drought and heat.
There are reports of tar spots all over the Midwest. What are your advice to farmers to manage it?
Harp: If you are in an area that has tar spots and there are environmental conditions conducive to tar spot, a fungicide application is recommended, even if it is late vegetative or if it is R1 or R2.
We have acres where we’re seeing a benefit from two applications. Most heavy lifting is done from the first application. We save maybe 30 bushels from the first application and if we make a second application we could get eight to 10 bushels more.
The first application is the most important. The late growing season up to R1 seems to be the best time for enforcement, and there are tools out there like the University of Wisconsin Tarspotter app.
Tarspotter uses GPS coordinates to determine if the weather was favorable for tar spot fungus to develop during the corn bloom in a specific field. The models in the app use local weather, gathered from the Internet, to predict favorable conditions for most corn growing regions. Based on these predictions and the crop phenology, a site-specific risk prediction is generated.
Make no mistake, the inoculum is in the field and as soon as weather conditions become favorable, you get a tar spot.
The more proactively you can use a fungicide application, the better the yield retention and the more value from that fungicide you will get.