ASK THE AGRONOMIST BLOG

While harvest season is underway in parts of the south and is just around the corner for the Corn Belt, growers aren’t out of the weeds when it comes to diseases that can impact yield. When combined with the right conditions, late-season corn diseases can decrease the quality and amount of grain and harvestability, so it’s important to continue scouting up until harvest to be on alert for affected areas. Here are some late-season corn diseases to look out for in August.  

Tar spot is a newer disease that continues to spread across the Corn Belt. First discovered in the United States around 2015, this disease — which can overwinter in the ground on infected crop residue — can also spread via wind and gusty rains. It favors cool, humid and wet conditions. Tar spot is caused by a fungus called Phyllachora maydis. It appears as raised black dots called stromata, which can appear on the leaves, stalks and husks of the plant. It’s often accompanied by fish-eye lesions, which are tan halos that surround the stromata. Tar spot can be confused with other pathogens, so it’s important to get a diagnosis from an agronomist or laboratory specialist to confirm. Unlike corn rust, tar spot fungus stromata cannot be rubbed off. Tar spot can lead to poor grain fill and stalk rot and lodging issues, which can be detrimental to a clean harvest and yield.

Stalk rots are environmental and include gibberella, fusarium, diplodia and charcoal rots, to name a few. Signs of stalk rot may not show up until later in the season but are usually exacerbated by hot conditions in both wet and dry environments. The biggest indicator of stalk rot is brittle stalks. Some of the bacteria may form different colored fungus on the stalks as well. Stalk rot can lead to weakened plants and reduced grain fill as it hinders the plants' ability to uptake water and nutrients. Brittle stalks can also lead to lodging, which makes it difficult to harvest. It’s recommended to apply fungicides early to mitigate stalk rots around the V6-V8 stages. 

Ear molds are environmental and can be caused by the same pathogens that cause stalk rots, such as gibberella, fusarium, diplodia and aspergillus. Symptoms include different variations and colors of mold on the ear. For example, gibberella mold is commonly red or pink in color, fusarium can be white to pink, diplodia can be white with black fungal spots and aspergillus is an olive-green mold. It’s important to note that there is some hybrid resistance to ear molds. The best way to prevent pathogens like ear molds, which can significantly reduce the quality of grain, is through fungicides. The pathogens causing the rot can continue to grow after harvest, so having the right storage available is essential if you plan to wait to take it to the elevator. Certain ear rots can also produce mycotoxins, which can affect livestock health.

Mitigation strategies are essential to protect your crops from these late-season diseases. Strategies can include fungicides, which your crop may still benefit from until the R3 stage; tillage to help break up the infected residue; crop rotation, which can keep the disease at bay as many of these diseases are only prevalent in corn; and investing in a hybrid that contains resistance to whichever disease you are tackling this year so that you're protecting your crop next year. 

When in doubt, contact your local Stine rep for guidance on late-season corn diseases. 

It’s no secret that Stine^® is a leader in the soybean industry. We have the industry’s largest breeding program and are consistently first to market with high-performing varieties in every maturity range with the traits growers want. In fact, our soybean lineup is more robust than ever and offers more material in more maturities than our competitors, including the industry’s broadest lineup of Enlist E3^® soybeans. Check out some of the Enlist E3 soybean lines our sales reps are hearing (and seeing) great things about this growing season.

Stine 12EB32 Brand Soybeans
Stine 12EB32 is a 12-maturity soybean featuring Enlist Duo^®, Enlist One^®, glyphosate and glufosinate tolerance. This variety offers very good emergence and above-average standability, in addition to a solid disease package with resistance to Rps1c Phytophthora root rot, brown stem rot and stem canker and with tolerance to SDS and sclerotinia white mold. In our Elite Yield Trials, Stine 12EB32 brand soybeans had exceptional yield potential, yielding 110.8% of trial average. Stine Corn Technical Agronomist Tony Lenz notes this product has been a “consistent variety for the past couple of years. It works on many different soil types and has an above average iron deficiency chlorosis tolerance for those heavier soil environments.”  

Stine 19EA32 Brand Soybeans
A 19-maturity soybean, Stine 19EA32 has strong yield potential, yielding 101.9% of trial average in our Elite Yield Trials. Stine 19EA32 is tolerant to Enlist Duo, Enlist One, glyphosate and glufosinate. It also features very good emergence and standability with a medium plant height. Stine 19EA32 is resistant to Rps1c Phytophthora root rot, SCN and stem canker; boasts tolerance to iron deficiency chlorosis and SDS; and is a salt excluder. Tony notes, “Stine 19EA32 brand soybeans are a proven top yielder year after year. They have an above average iron deficiency chlorosis score, which makes it a very versatile variety.”

Stine 37EC20 Brand Soybeans
Stine 37EC20 is a high-yielding 37-maturity soybean. In fact, it yielded 106.2 percent of trial average in our Elite Yield Trials. Growers can achieve maximum weed control with this product as it features tolerance to Enlist Duo, Enlist One, glyphosate and glufosinate herbicides. The benefits of Stine 37EC20 are vast, including very good emergence, medium plant height, very good Phytophthora root rot tolerance, and SCN and stem canker resistance. Stine RSA Kevin Krabel notes, “37EC20 is one of my favorite varieties we have in Group 3. You can put it almost anywhere. It’s going to yield for you at normal planting time, and it’s a great double crop option. I recommend planting in the 140,000 range as this variety will bush out.”

Stine 40EB22 Brand Soybeans
Stine 40EB22 is a 41-maturity soybean with great yield potential. This product yielded 107.4 percent of trial average in Stine’s Elite Yield Trials. Growers receive peace of mind and herbicide flexibility with the ability to use Enlist Duo, Enlist One, glyphosate and glufosinate herbicides. Stine 40EB22 brand soybeans produce plants with a medium plant height with very good emergence and standability. They also boast a great disease package, including very good Phytophthora root rot, SCN and stem canker resistance and very good SDS tolerance. Stine Eastern Division Sales Director Ben Grinnell notes that Stine 40EB22 promises, “great yield potential” and is “one of my favorites because it works good in both early and double crop situations along with a great sudden death and soybean cyst nematode package.” 

Stine 48EB20 Brand Soybeans
A 48-maturity soybean, Stine 48EB20 offers growers outstanding weed control and herbicide flexibility through Enlist Duo, Enlist One, glyphosate and glufosinate tolerance. This product features very good emergence and strong standability with an excellent disease package. Growers benefit from the product’s very good Phytophthora root rot tolerance, good iron deficiency chlorosis tolerance, SCN and stem canker resistance and SDS tolerance. Stine Corn Technical Agronomist Mike Smith notes, “48EB20 has been a staple in the mid-south since its introduction. It has high yield potential for variable soil types combined with weed control with the E3 platform, which makes these genetics a winner for growers from Missouri through the delta region.”

To learn more about Stine’s 2022 soybean lineup, contact your local Stine sales rep today.

As reports of dicamba damage increase across the country, Stine founder and CEO Harry Stine has been candid in his conversations about the herbicide injury growers are seeing and the falsehoods that are spreading about the true culprit. While we still have a lot of samples from multiple fields that are still processing, we can confirm that elevated levels of dicamba are present in the results we have received thus far.

In late June, various test samples were taken from a field north of Knoxville, Iowa, and submitted to the South Dakota Agricultural Laboratories. The results detected just one chemistry present on the samples — dicamba, which registered 2.66 ppb. Stine RSA Dustin Ellis notes, “This field was one of the first fields that I was called about toward the end of June and is north of Knoxville. The entire farm was cupped. Even today, you can still see the new growth with little cupping, which is one characteristic of dicamba.”

Samples from two fields near Lindsay, Nebraska, also came back with elevated levels of dicamba, with 10.2 ppb of dicamba registered in one and 8.81 ppb in the other. No other chemistries were detected in the foliage samples.

As we test more fields throughout the country, we’ll continue to report our findings. If these early test results are any indicator, dicamba is undoubtedly the culprit of the damage we’re seeing in our fields.

As a reminder, Stine growers who are experiencing suspected dicamba damage in their fields are eligible for free sampling through Stine. Contact your local Stine sales rep if you suspect dicamba in your fields.