Digital Corner
Assessing Crop Stress and Recovery Strategies
Wheat harvest continues, a few weather challenges to content with. However, yields are beating expectations which is always good. The opportunity for double crop soybeans is slipping away. Perhaps a cover crop may be in order to suppress weeds, build soil organic matter.
We are approaching VT growth stage on corn and are preparing plans for fungicide applications. Tar Spot has been confirmed and weather is increasing the risk level for infections to occur. Applying a protective fungicide will limit the incidence and severity of disease development.
Excessive rains and hail last week as caused some crop injury. In unharvested wheat some kernels were knocked to the ground with yield loss estimates of 3 to 20 bushel per acre.
Some corn has experienced significant leaf damage with estimates of 20 to 50% leaf damage this may translate into 5 to 20% yield reduction. Applying fungicide does little to reverse any hail damage however depending on the yield potential and the degree to which the whole field is damaged may still merit a fungicide application if Tar Spot and Northern Corn Leaf blight are evident. Certainly, continued wet weather will be conducive to Gibberella ear mold and a spray timed for R 1 growth stage (silking) may suppress the potential of DON development.
Hail can cause varying degrees of leaf damage from a few holes to tattered leaves to stripping the leaves completely off the plant.
Soybeans of all the crops can handle the hail damage better. Once again depends on the severity of damage and where stems are broken. Soybeans can regenerate new branches from the axillary buds at lower nodes and continue to produce flowers and pods.
Hail has broken off a portion of the main stem. New growth is initiated from the node below the damage.
On other fields we have areas that have severe water damage in low slopes and the recovery is in question in those areas. The soybeans look good on the higher better drained soils and may be prone to foliar pathogens. Protecting good beans with a fungicide is still possible by only turning the sprayer on in the good areas and shutting it off in the poor areas. Do not need a lot of technology to be site specific.
Using dead reckoning to apply fungicide based on crop condition.
As always, our
Crop Specialists areavailable to help assess the best strategy for maintaining crop health andcapturing yield potential. Never give up.
Article by Dale Cowan
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Managing Tar Spot Effectively in Your Corn Crop
Tar spot disease in corn can cause significant yield losses for corn growers, so it’s important to be aware of the disease and take steps to reduce the severity. Early recognition of the symptoms and careful management are key to reducing losses and protecting the health of your crop.
The fungus, Phyllachora maydis, survives the winter on infected corn residue from the previous growing season then is spread by wind-blown spores and is active from mid-June to the end of season. The fungus thrives in high humidity; therefore, it is more common in seasons with moderate to above average rainfall. Duration of leaf surface wetness appears to be a key factor in the development and spread of tar spot.
It is important to recognize the symptoms of tar spot disease early in order to prevent it from spreading. The fungus produces numerous black fruiting bodies (called stroma) on the upper and lower surface of the affected leaves. Lesions cannot be rubbed away or dissolved in water. The spots are small and the edges are brown in color. As the disease progresses, the leaves yellow and die, as it spreads from the lower leaves to the upper canopy, leaf sheathes, and eventually the husks of the developing ears.
Figure 1 photo OMAFRA field crop plant pathologist Albert Tenuta
Managing the disease involves controlling the fungus in the environment. There are a few different methods and approaches to control tar spot disease, one of those is by using fungicides. Fungicides are applied to the foliage of the plant at proper times throughout the growing season. To make sure that tar spot disease does not spread, fungicides must be applied as soon as the pathogen is detected. The optimum fungicide application timing in most years for control looks to be at growth stage VT/R1 (tassel emergence/silking) to R2 (milk). Three fungicides to focus on for suppression of tar spot are Veltyma DLX from BASF and Delaro Complete from Bayer Crop Science and Miravis NEO from Syngenta.
Other effective types of control in reducing tar spot infection include cultural control methods, such as crop rotation and using tolerant hybrids. Seed companies are beginning to identify tolerant hybrids. In 2021 OMAFRA in collaboration with corn seed companies began evaluating the tolerance of commercial and experimental corn hybrids to tar spot. Even though their findings showed that only a few hybrids could be considered highly tolerant to the disease we still greatly appreciate the time and energy that goes into collecting this data in order to help us make sound hybrid choices on a field-by-field bases.
Make sure to reach out to your local AGRIS Crop Sales Specialist for help identifying and managing tar spot effectively and other foliar fungal pathogens in your fields.
Article by Cory Cowan
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Effective Fall Management Starts Now
As the wheat season is almost over, it is time to start your Fall weed control plan.
Time for adding fall burndown to your weed management plan. As winter approaches, weeds will start to store sugars in their roots as a reserve for the spring. The herbicide application will be very effective because it will flow to the root system. The plants will not be able to recover after winter and your next crop will start in a clean field.
The control of weeds like dandelions and Canada-thistle, a headache in the 2023 season, is much more effective in the Fall than in the Spring where the spraying window is more constantly affected by weather and crop stage.
Something to avoid by using fall weed control program. Canada Fleabane in winter wheat.
Another component of weed control in the fall is the use of cover crops. If planted right after the wheat, cover crops can work as a physical barrier to weed growth. Make sure planting and termination dates are planned to provide enough biomass to suppress weeds by blocking sunlight or competing for resources. Choose the right cover crop and the right herbicide program for the job with the help of your AGRIS Crop Specialist.
Keep in mind that the 2024 crop success depends on competent 2023 Fall management.
Article by Andre Coutinho