Tar Spot: Expert Control and Management Resources
Tar spot is an aggressive fungal disease that rapidly destroys corn leaf tissue, leading to significant yield loss and reduced stalk integrity. To protect your crop, scout your fields for small, raised black lesions and use proactive management strategies such as hybrid selection, residue management and well-timed fungicide applications. Stay ahead of outbreaks with the latest tar spot scouting tips and expert control recommendations for the current growing season.
With varying degrees of severity being reported, agronomists and growers are evaluating whether to spray this late in the season. Check out the Crop Protection Network interactive map to see if the disease is in or near your county.
Mike Jenks shares how he reconfigures nozzles, boosts carrier volume and evaluates application timing to protect the leaves that drive grain fill.
With tar spot at fairly low levels, Midwest agronomists encourage farmers to focus on protecting the upper canopy, keying into the best application timing and keeping an eye out for southern rust.
With Midwest farmers reporting disease lesions on leaves in storm-hit cornfields, an Iowa State pathologist says the right management step hinges on correct identification.
Ken Ferrie leads the unsponsored, two-day event focused on crop fertility ROI, weed management and making the 4Rs pay in tight markets.
Ken Ferrie lays out a strategy for farmers struggling with ponded corn acres after rains soak parts of the Midwest.
A new report details the need for more ag funding to address existing weeds, insects and diseases as well as agronomic problems that have yet to reach U.S. shores.
The disease is causing turmoil for farmers who have a large crop in the making. In some cases, a Hail Mary fungicide application at R4 up to early dent (R5) might make sense this season, say agronomists.
On the heels of Crop Tour, Pro Farmer projects corn yields at 6.1 bu. below USDA’s August estimate, while soybean yield numbers are nearly aligned.
Iowa could be the nation’s top state this year for corn and soybeans, but both crops are in a race to beat disease pressure that’s gaining momentum. Illinois corn continues to ride the struggle bus, while the soybean crop there is positioned to deliver high yields.
There is still up to 55% of the kernel dry weight left to be accumulated by many corn hybrids at this point — starch that can contribute significantly to grain fill and higher test weights.
Got tar spot? Economic data shows two passes can offer ROI, depending on the hybrid. However, if your crop got dinged at pollination that’s a different scenario and might require a revised game plan that takes yield estimates into consideration.
Farmers and aerial applicators tell Randy Dowdy and David Hula some of the key considerations for effective fungicide applications are timing, droplet size and product reach in the crop canopy.
Unlike most leaf diseases, tar spot starts impacting the crop at the bottom of plants. That means fungicides you apply must penetrate and get deep into the crop canopy to provide effective treatment. If you opt to not treat the disease, consider making plans to harvest early and pre-booking some dryer gas.
Now’s the time to be scouting for the disease, especially where the inoculum is present. Tracking weather data, particularly daily humidity levels, can help you keep an eye on tar spot this season.
Corteva Forcivo will feature three modes of action to address foliar diseases in corn, soybeans, wheat and other crops via overlapping preventive and curative activity.
Despite being outside the optimum window for tar spot control, this Wisconsin field trial yielded strong results.
Iowa farmers say a foliar fungicide application can add more bushels per acre by preventing losses to disease pressure and minimizing the impact of environmental factors, such as heat stress and drought.
Scientists from the Agricultural Research Service have identified several different species of fungi and bacteria that can stop tar spot from developing.
There’s a big crop in the field for many Midwest growers, and it requires fuel. N supplies ears with the energy they need to add kernels all the way to their tips and to pack on weight.
If you have tar spot, Southern rust or other disease pressure and plan to dry the crop in the field, you might want to spray again.
When average daily humidity levels reach and stay at 75% or above, that’s a signal your crop could be at high risk from the disease.
Some growers are struggling with waterlogged fields that are producing stunted, yellowing corn. Field Agronomist Ken Ferrie offers farmers hope and help with his practical, no-nonsense recommendations.
Ken Ferrie outlines various treatment scenarios, depending on what farmers find in their fields. He cautions that severe infections can easily cause 60-bu.-per-acre yield losses.