ASK THE AGRONOMIST BLOG

A wet spring in Ohio. A season-long drought in the central and northern Corn Belt. Mother Nature provided all forms of weather for us this growing season. Unfortunately, those unfavorable conditions have led to a handful of late-season diseases that are starting to rear their inconvenient heads as harvest begins.  

Tar Spot
Tar spot is a fungal disease that affects corn. It appears as small raised black spots on the leaves and husks of plants that sometimes can produce fisheye-like lesions. While it can often be confused with corn rust, one way to distinguish tar spot from other diseases is that the black spots will not rub off at the touch. That said, it’s always best to work with your local extension experts or a lab to diagnose the disease.

Unfortunately, tar spot can cause significant yield damage as infected plants can be prone to top leaf dieback, poor grain fill, compromised stalks and plant death. Tar spot this late in the season can lead to stalk rots and lodging, so it’s important to scout fields that may be impacted and perform the push/pinch test on your stalks to determine what fields need to come out first.  Tar spot tends to favor wet, humid climates, so growers who experienced wetter-than-normal growing conditions and long periods of humidity may have fields susceptible to the disease. Tar spot is also able to overwinter in the ground, so while growers may not be able to tackle the disease this late in the season, they must plan for next year by selecting a hybrid with a better tolerance rating to tar spot or exploring relevant seed treatments with added fungicides. And a best practice with all diseases: Rotating the crop to a non-corn related crop can help keep tar spot at bay.

Stalk Rots
Stalk rots in corn are common at this time of year and can include different types of rot, such as gibberella, fusarium, diplodia and charcoal rots. This biggest indicator of stalk rot is brittle stalks that may be discolored as the fungus takes hold. As we discussed in last week’s article, growers really need to scout their fields to check for areas where stalks may be compromised so that they can prioritize those affected fields for harvest. And if the plant does snap, bend or feel soft to the touch, it’s good practice to split the stalk open to check the severity of the fungi feeding on the structural tissues and lignin.

Sudden Death Syndrome
As Stine Regional Sales Agronomist Grant Collier recently reported in Ohio’s Country Journal, sudden death syndrome (SDS), which is considered “one of the top two most destructive soybean diseases in the U.S.,” is present in areas of the country. Its presence is worrisome this year in his region in Ohio as a combination of moisture with cool weather has exacerbated the fungus. He notes soybean cyst nematode (SCN) is often found in conjunction with SDS and may be another culprit of SDS.

Symptoms of SDS include soft, rotten roots, discolored stems, fungus masses on the root, yellowing of leaves and leaf drop. While growers may not be able to do anything for SDS or SCN this season, selecting soybean varieties with both SDS and SCN resistance can slow the presence of the diseases in your fields next year. Stine has a number of varieties that are effective in controlling both diseases. Rotating to corn is also a good practice for minimizing risk, and as Grant notes, “minimizing tillage is essential to limiting the spread of SDS throughout your field, as well as SCN.”

To learn more about what diseases can be present in your fields this fall and how to get ahead of these diseases next year, contact your local Stine sales rep.

The September 27 Crop Progress Report notes that 18% of corn has been harvested in the United States. Of the entire corn crop, 14% is listed in excellent condition and 45% good, 26% fair, 10% poor and 5% very poor. For growers who haven’t started corn harvest yet, now’s the time to check each field for stalk integrity and standability. Stalk quality and standability will be a concern in areas where lack of moisture and nitrogen have caused plants to cannibalize the stalks in order to finish ear development. Fields with more than 10% of the plants exhibiting stalk issues should be considered for early harvest. Here are some tips for assessing stalk quality and standability.

Walk the fields
As you do throughout the growing season, get out and scout. Don’t just check the edges of fields. Check areas where ponding or heavy moisture occurred throughout the year or dry, stressed areas. Or, if you experienced plant stress at any point throughout the growing season, check those areas to make sure stalk lodging or breakage hasn’t occurred. Stalk discoloration may be an indicator of poor stalk quality, but one of the easiest ways to check if your stalks are compromised is the old-fashioned push and pinch tests or by cutting the stalk in half.

Push and pinch test
The push and pinch tests are exactly what their name indicates. The push test is simply pushing the stalk over. I recommend doing this at a 45-degree angle. If the stalk doesn’t return to its natural upright position or if it kinks or crushes at the bottom, that’s a good indication that your stalks are compromised, and harvest should begin as soon as possible.

The pinch test is simple, but where you perform the test on the stalk is important. To execute the pinch test, use your thumb and forefinger to pinch down on the stalk roughly one foot off the ground. Next, run your fingertips up and down the stalk. If you feel your fingers touching and both sides can squeeze together, that’s a good indicator that the stalks are compromised and could lodge if not harvested soon. If the stalk is also soft and squishy to the touch, that’s a good sign that the field is ready to go.

Examine the inside of the stalk
Another common practice for examining stalk quality is to cut open the stalk, preferably in half lengthwise. Stalks should be selected at random throughout a field, and you want to look at more than one plant per section. Experts recommend randomly selecting a minimum of 100 plants per field for either of the tests. When you open the stalk, you’re looking for discoloration or rotting of the pith or areas that are hollow with hanging vascular strands. 

Scout for stalk rot
When scouting for stalk quality and standability, be on high alert for symptomology of stalk rot. Stalk rots, such as anthracnose, Fusarium and Gibberella, typically occur as a result of pathogens or environmental stressors. These pathogens like to infect plants that are already weakened, and different stalk rots have different features. Gibberella, for instance, causes dark streaks on the outside of the stalks and a noticeable dark pink to red pith when the stalk is opened. Anthracnose appears as black lesions on the outside of the stalk, and Fusarium develops brown steaks on the outside of the stalk with white to light -ink discoloration inside the stalk.

Recommendations
If stalk rot is present in your fields or if you detect weakened stalks in various areas, prioritize those fields for harvest based on which field is at a greater risk for lodging. This may help you save time and yield this fall.

For next year, consider corn products with excellent disease and insect control packages and ones that respond well to stress. Work with your local Stine sales rep to determine which product will work best for your situation. Happy harvesting!

According to the most recent National Census of Fatal Occupational Injuries report (2019), farmers, ranchers and other agricultural managers have among the top most dangerous jobs. Of the dangerous occupations listed, transportation incidents and falls, slips and trips were the top reasons for fatalities. Farm safety is imperative to the livelihood of a farm operation and its operators. In honor of National Farm Safety and Health Week, we’ve dusted off a few of our most important tips to keep you, your family and others F.A.R.M. S.A.F.E. — not only this harvest season but year-round.

Familiarize yourself with potential health and safety hazards on the farm and in the field. Ensure all employees and family members are adequately trained when using any farming equipment. A lack of experience or training can put anyone at risk on the farm.

Alert children about these hazards. Whether helping a parent out in the field or playing on or near farm equipment, children are always at risk of a slip, fall or spill. Consider finding farming safety courses for youth through your local extension office or use online resources to help teach your children the do’s and don’ts around farm equipment.

Rest — it’s important! Long hours in the field contribute to fatigue, which can lead to increased accidents on the farm. While you’re burning the midnight oil, make sure you and your team are well-rested, hydrated and in good health to prevent any accidents, injuries or other setbacks.

Maintain and inspect your farm equipment to ensure it’s running properly before you hit the field. Last week, we provided some of our favorite pre-harvest safety tips for inspecting your equipment. But remember — inspecting and maintaining equipment is a year-round job. Always take a walk around your equipment before you begin operating to check for any wear and tear, loose parts, flat tires and more. Ensure all lights are in working order, especially as you work in the late hours or early mornings, so you (and others) can see where your equipment is heading.

Steer clear of loose clothing around farm equipment as it can get caught and lead to trips or dangerous falls. This is especially true around augers and other equipment where parts are continually in motion. And always wear protective equipment such as gloves, goggles and steel-toed boots to help reduce farm-related work injury.

Avoid power lines, gas pipelines and other hazards on the road. Adjust equipment to its lowest level when traveling so that you’re at least 10 feet or more from power lines. If you plan to dig on your property, remember to call 811 in advance to have gas pipelines and underground electric wires marked before you start a project. And always be aware of your surroundings when driving, especially in areas where children are present or on busy county roads and highways.

Follow instructions. Read safety manuals to ensure you properly operate farm machinery. Each piece of equipment should have manufacturer recommendations for safety usage within its manual.

Employ the buddy system when operating dangerous equipment or working in grain bins or with vertical elevators and augers. Grain bin safety is especially crucial this time of year. Also, wear a mask in and around grain bins and silos to prevent diseases or conditions related to dust and gas inhalation. Always have another person present as you enter a bin and secure yourself to a harness or rope to ensure you have a solid escape plan.

Keep farm safety top of mind today and always. Be aware of your surroundings, know your limits and have an emergency plan in place. Get more tips on harvest safety from your local extension office or by visiting with a Stine sales rep.