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June 12, 2024 by McKenna Greco

While soybean aphids haven’t been much of a problem over the last few years, they do have the potential to be harmful — particularly in soybean fields with pressure from other insects. Soybean aphids are a unique and challenging insect, especially when you are trying to eliminate them from your soybean fields. These adaptive, invasive insects only reach 1/16 inch in length. Yet, what they lack in size is made up for in quantity.

Scouting for Soybean Aphids

In the summer, soybean aphid populations boom. With high birth rates and short generation times, populations can double every two to three days when conditions are right. Aphids in overcrowded fields can produce winged forms that easily spread to neighboring fields. Depending on the temperature, growers can expect up to 18 generations of soybean aphids from May to August.

You’ll know you’re dealing with soybean aphids when you spot small, pear-shaped yellow insects with black cornicles near the rear. These pests are typically found on the underside of soybean leaves. As aphid pressure increases, white flakes become more apparent on the surface of leaves. These are the cast skins of molting nymphs.

Another reliable indicator of soybean aphids is the presence of natural predators like lady beetles and minute pirate bugs. Often, ants will be easily visible on the stems of plants affected by soybean aphids.

Why Worry About Soybean Aphids?

Due to their high reproductive potential, a few soybean aphids can quickly become a serious threat. Feeding damage can weaken plants and make them more susceptible to other stressors like drought and disease. Soybean aphids extract plant juices through their needle-like mouths and excrete honeydew, a sugary waste product. Sooty mold can develop on the honeydew excretions and cause yield losses of up to 40%.

Aphids pose the greatest threat to soybean yield during the R1-R4 stages. When contemplating treatment, consider the growth stage of the plants, other stressors and natural predators. Treatment may not be necessary if plants are in later growth stages, if stressors are low or if there are many natural predators in the fields.

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The University of Minnesota Extension  recommends scouting and counting aphids throughout the growing season. If the average number of aphids on each plant exceeds 250, this means that the economic threshold is reached and an insecticide application is needed to protect your yields from damage. This threshold is considered the tipping point because insecticide applications at lower pressure may not pay for the cost of application.

If the economic threshold is reached, effective insecticides like Endigo® ZCX are necessary to prevent economic injury. Endigo ZCX contains two complementary modes of action to protect yields from soybean aphids and other insect pests. For more information about the economic threshold and solutions for your soybeans, contact your local Syngenta representative.

June 7, 2024 by McKenna Greco

When it comes to combatting tough pests, nothing beats advice from local experts. Learn about the top weed, disease, and insect pest threats in the Midwest, Mid-South and Southeast before they show up in your fields. Plus, get tips for scouting, preventing and treating tar spot, stink bugs and Palmer amaranth in your corn and soybean fields.


Infographic outlining the top three pest threats to look out for in the 2024 growing season, including tar spot, stink bugs, and Palmer amaranth. Descriptions of each pest include appearance, habitat and ideal conditions, the type of damage it inflicts on crops, and agronomic tips to prevent each pest.

Tar Spot

Stink Bug

Palmer Amaranth

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1 https://www.noaa.gov/news/us-had-its-warmest-winter-on-record

2 https://www.canr.msu.edu/news/msu-researchers-identifying-corn-tar-spot-management-strategies

3 https://www.agweb.com/news/crops/corn/you-cant-afford-be-complacent-about-tar-spot

4 https://www.extension.purdue.edu/extmedia/bp/bp-90-w.pdf

5 https://www.youtube.com/watch?v=CI62h71g6qQ

6 https://www.canr.msu.edu/ipm/Invasive_species/brown_marmorated_stink_bug

7 https://extensionentomology.tamu.edu/insects/redbanded-stink-bug/

8 https://www.epa.gov/safepestcontrol/brown-marmorated-stink-bug#:~:text=In%20the%20United%20States%2C%20the,in%20the%20mid%2DAtlantic%20region

9  https://edis.ifas.ufl.edu/publication/IN1176

10 https://site.extension.uga.edu/benhillcoag/files/2022/08/Redbanded-Stink-Bugs.pdf

11 https://www.mda.state.mn.us/palmeramaranth

12 https://www.fsa.usda.gov/Assets/USDA-FSA-Public/usdafiles/FactSheets/archived-fact-sheets/palmer_amaranth_nrcs_national_factsheet.pdf

June 5, 2024 by McKenna Greco

What does it take to plan an effective insecticide program for your tree nuts? Pest management programs should start with good monitoring protocols, knowing how to identify when it’s the right time for treatment.

According to the University of California IPM program, the initiation of hull split is the most effective timing for a single insecticide application. Once you are at 1% hull split and pest flights are present, it’s time to put an effective insecticide program in place to protect your quality and yield potential. Otherwise, these pests can wreak havoc on your tree nuts and even cause fungal infections.

Controlling NOW

Tree nuts are most vulnerable to damage from pests during hull split, as the exposed nut gives navel orangeworm (NOW) and other secondary insects direct access to the nut inside. Larvae bore into the nutmeat and produce large amounts of webbing and frass as they grow. This feeding leads to fungal infections and contamination.

When applied properly and at the right time, a strong pest management plan can help you protect your tree nuts and maximize yield potential from the mummy nut phase through harvest. It’s recommended that you apply a first spray at early hull split and follow-up with a second spray around 10-14 days after.

Navel orangeworm damage on an almond.
Navel Orangeworm larvae and damage in almonds. Source: Syngenta USA Project 2021. Huron, California, USA. Almonds. Westside Harvesting.

Defend Against Spider Mites

In addition to NOW, spider mites are also a major problem pest that you should look out for. Mites can damage your foliage by extracting from your trees’ leaves, causing them to turn yellow and fall off. High numbers of mites can also cover tree terminals with webbing. The University of California IPM program found that crop reduction and reduced vegetative tree growth typically shows up the year after damage occurs.

According to the Sacramento Valley Orchard Source, spider mite management can be accomplished through one of two general approaches:

  • The threshold and biological control approach helps maintain a balanced ratio of natural enemies-to-spider mites that will allow the beneficials to help suppress spider mite populations by only treating spider mites once economic thresholds are reached, not before.
  • An early-season prophylactic approach can be very effective in controlling mites well into summer. However, there could be a downside that may contribute to a later season mite flare up as treatments wear off.
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The key to managing and preventing further infestation of damaging pests is to get ahead of them early with a May spray and continue to treat orchards every two to three weeks to maintain control.

Effective Insect Management

With powerful pest management tools, growers and consultants can execute a customized plan to stay ahead of pests throughout the season.

  • Minecto® Pro insecticide is a broad-spectrum foliar insecticide that controls navel orangeworm and other damaging secondary pests, including mites in tree nuts. Flexible enough to fit into any management plan, complementary ingredients cyantraniliprole and abamectin combine to form a convenient premix formulation that protects against multiple overlapping pest populations such as mites and navel orangeworm. A May spray application of Minecto Pro is important if there are remaining mummies on the trees from the prior season and the time to consider a proactive spray for mites.
  • Besiege® insecticide provides dual-action protection against the most difficult lepidopteran pests, including navel orangeworm, peach twig borer, codling moth, leaffooted plant bug and walnut husk fly. With long-lasting residual and outstanding knockdown, Besiege is ideal for application at hull split.

Building an insecticide program with a combination of these products can help you manage insects in your orchards this season.

June 1, 2024 by McKenna Greco

Throughout the course of the almond growing season, there’s always the potential for disease to strike, damaging not only your quality yield potential, but also the overall health of your trees if not properly controlled.

It Starts at the Roots

Like the foundation of your home, the roots of your almond trees play a critical role in the support of your orchards. It’s important to protect your roots so that diseases like Phytophthora root rot and crown rot don’t creep in during dormancy. The soil and roots are important drivers for plant processes that can’t continue if the roots are compromised. To help ensure the long-term health of your orchard, you should be scouting often and applying effective fungicides at the right time to achieve the best yield potential.

The wet and warm conditions during the growing season can create the perfect environment for diseases. Phytophthora root rot is an infection that occurs around the lateral part of the root system of crops, which causes a gradual waning of tree health and productivity that can linger for years. Phytophthora crown rot is an infection that occurs close to the base of the tree, underground, which plugs the vascular system leading to a ghostly death in as early as a week.

Orondis® fungicide is a solution that promotes overall tree health and longevity by combatting multiple Phytophthora pathogens. An application of Orondis during spring root flush can set you up for success in the following season by helping to improve root mass, leading to better nutrient and water intake. It is also recommended to make a second application post-harvest to prevent Phytophthora pathogens from making an appearance when temperatures are high and the soil is damp in the late summer.

A chart shows reduced Phytophthora propagule count with Orondis fungicide.
Orondis protects roots by reducing Phytophthora propagule count and inoculum potential.

Protect Buds and Blooms

Tree nuts are susceptible to a variety of early-season diseases that can be harmful to growing nuts, detrimental to yield and impact the overall health of the plant. Blossom blight is one of the most devastating diseases an almond tree might encounter because it can kill an entire stem.

Warm, humid climates with extended periods of wetness, as well as previous year infections, foster the pathogen that causes disease. Infected fruit mummies on the orchard floor and left in the tree produce spores. The pathogen infects blooms which turn brown and collapse. Infections can extend to the twig and young leaves resulting in gumming and cankers on the stem.

To prevent infections, prioritize good orchard sanitation and make the first recommended fungicide application just before bloom at the pink bud stage. An application of Miravis® Prime fungicide will help dial up your defense against the most damaging diseases like blossom blight. Powered by ADEPIDYN® technology, Miravis Prime offers long-lasting disease control to keep trees healthy and improve almond quality.

A bar chart shows that Miravis Prime protects almond yield potential from brown rot blossom blight.
Miravis Prime protects almond yield potential from brown rot blossom blight.

Optimize for Growth

As spring transitions into summer, your almond trees are hard at work maturing kernels to full size. As the outer hull begins to develop, diseases like Alternaria leaf spot can creep in and rob you of your profit potential.

Alternaria leaf spot disease is typically prevalent from spring to summer and causes large brown spots on leaves that turn black as the fungus produces spores. Like many diseases, it can overwinter in plant debris from the previous year and favors high humidity and wet springs. Keep an eye out for leaf spots to prevent potential yield loss and defoliation.

A preventative application of a strong, broad-spectrum fungicide during this critical growth period is the best way to protect your trees from devastating disease and improve the longevity of your crop. Miravis Duo fungicide targets and prevents these tough diseases using a combination of ADEPIDYN technology and difenoconazole, giving your trees the best chance at potentially producing a quality yield for many seasons to come.

A bar chart shows Alternaria leaf spot protection in almonds with Miravis Duo.
One application of Miravis Duo outperforms competitors in protecting against Alternaria leaf spot in almonds.

A Season-long Approach

Don’t wait for diseases to strike your almond orchards. Syngenta offers a season-long approach to help you manage disease not only in the current growing season, but in future seasons to come. Contact your local representative to develop an effective management plan that works for you.

May 9, 2024 by McKenna Greco

Reach for your trusty Farmers’ Almanac to predict this season’s weather, but turn to Syngenta agronomy service representatives (ASRs) for the latest on this season’s most threatening pests. These ASRs use their regional experience and knowledge to predict which insects, weeds and diseases you should scout for in 2024.

Midwest Growers: Watch Out for Waterhemp and Tar Spot

Indiana

Waterhemp is a driver weed in the ‘Hoosier State’ according to Chad Threewits, Syngenta ASR in Fort Wayne, IN. Poor weed control last year increased this year’s seed bank, he says, adding that Canada thistle and giant ragweed will also be a factor in both corn and soybean fields.

It’s predicted that pre- and post-emergence herbicide applications will be crucial to limiting prolific weeds this season — and are an investment in future crops as well. “Developing herbicide programs that help control these driver weeds not only keeps fields clean this year but helps limit the pressure by reducing the seed bank for the future,” Threewits says.

As in many regions, tar spot is now Indiana’s driver disease in corn. “It’s shown up everywhere in the state, and the severity will depend on summer weather,” Threewits says. Moderate temperatures and wet weather can drive tar spot development, while hot, dry days can decrease its impact. However, don’t bet on the weather to stay on your side.

“The timing of fungicide needs to occur right at the onset of tar spot,” Threewits says. “A lot of growers want to wait, but to maximize yield we can’t let it get ahead of us.”

Some other molds may keep Indiana corn and soybean growers up at night. Ear mold and white mold were big problems in 2023, so they’re top of mind again this year. Threewits also advises soybean growers to keep an eye out for bean leaf beetles and stink bugs, especially late in the season.

Illinois

Illinois growers can expect to battle waterhemp this season according to Kevin Scholl, Syngenta ASR in northern Illinois. “I always say if waterhemp is not your main target weed, it’s going to be. You’ve got to get it under control to have a successful harvest,” he says.

Scholl says waterhemp is a late-season emerger; he recommends a two-pass program with a pre-emergent herbicide followed by an early post-application. “The bigger it gets, the harder it is to kill. That’s why we try to stay ahead of it,” he says.

The top-of-mind disease in corn is, not surprisingly, tar spot. Scholl says northwest Illinois endured one of the nation’s first major outbreaks in 2018, which left a legacy not just in the fields, but in the way growers treat other foliar diseases in corn.

“The 2018 tar spot outbreak changed the way we make recommendations for diseases like gray leaf spot, Northern corn leaf blight and common rust,” he says. While they used to advise tassel to green silks as the best timing for fungicide application and plant-health benefits, Scholl says it now depends on the disease’s timing.

“If tar spot comes in earlier than that timeframe, we need to pull the trigger and spray a fungicide when we see it start to build, especially if the weather conditions are conducive,” he says.

Likewise, soybeans need early intervention to prevent Sudden Death Syndrome. “Sudden Death Syndrome infects the plant early in the season but doesn’t really show itself until the soybeans start to flower,” Scholl says. “For control early in the season, we’ve had very good luck with Saltro® fungicide seed treatment.”

Scholl says the primary insect pest in corn continues to be corn rootworm, which packs a one-two punch by chewing away at corn roots as larvae, then clipping silks as mature beetles. “The beetles lay their eggs in the fall, in corn fields or sometimes in soybean fields, so you can’t really get around this pest with just rotation,” he says. “I advise planting a traited-hybrid seed and applying an insecticide right at planting.”

An insecticide like Force® Evo or Force 6.5G can help protect the corn’s roots. “If you’re losing root mass, you’ll lose the capacity to bring up moisture and nutrients, and that plant’s going to suffer in the end,” Scholl says.

Central Plains Growers: Beware of Palmer Amaranth and Tar Spot

Kansas

The biggest weed threat in western Kansas continues to be Palmer amaranth according to T.J. Binns, Syngenta ASR in Kansas. “It’s a difficult weed to control due to its prolific seed production, rapid growth rate and continuous emergence through the growing season,” he says.

“Palmer amaranth takes work to manage in a perfect year. In 2023, a big hail weather event opened up the canopy late in the season which allowed even more Palmer to go to seed,” Binns says. “So, we’re expecting it to be an even bigger challenge in 2024.”

All Kansas row crops are affected by Palmer amaranth, but Binns says it’s especially damaging in grain sorghum (milo). “In milo, there really aren’t any herbicides to control Palmer amaranth once they emerge. It’s a helpless feeling when it happens,” he says.

To limit weed impact in corn and soybeans, Binns recommends robust rates of pre-emergence herbicides followed by early application of overlapping residual herbicides before the weed comes up.

“We’re moving in the same direction with milo — overlapping residuals and a quality pre-emergence product,” he says, adding that in this crop, timing is crucial. Binns also notes a warmer-than-normal spring could cause Palmer amaranth to emerge earlier than usual in all crops.

Wheat growers will want to be mindful of stripe and leaf rust, along with Fusarium head blight (FHB), which could undermine a promising crop. “FHB has become more common in the last few years and a lot of growers were caught by surprise with the amount of infection in 2023,” Binns says.

Growers impacted by FHB last year have already taken steps to protect against it in 2024 by making variety selections that offer higher levels of tolerance for the disease. “Variety selection is the first step,” Binns says. “But even with variety selection, they need to be considering a Miravis® Ace fungicide application, ideally at bloom if the weather conditions are conducive for FHB infection.”

Binns also advises growers to be aware of rust progression from the south and start preventative fungicide applications as soon as the flag leaf is 50% emerged — before the rust lesions appear on their wheat.

Nebraska

ASR Travis Gustafson’s territory, Nebraska, has a lot in common with neighboring Kansas. Palmer amaranth is a big concern in both corn and soybeans, and control depends on pre- and post-emergence herbicides if growers want the upper hand.

In corn, Storen® herbicide has performed well in demo trials for the last couple of years, Gustafson says, and he expects it to be a premium choice for managing Palmer amaranth in 2024. For soybeans, he recommends growers rely on Group 15 residual herbicides to control the pest, such as Boundary® 6.5 EC, Tendovo® and BroadAxe® XC.

“These herbicides provide great small-seeded broadleaf residual control early in the season and provide a foundation for more residual activity with post-emergence applications,” Gustafson says. He adds that it’s important to use residual products in both pre- and post-emergence applications to hold back later-germinating Palmer amaranth before the soybean canopy closes.

Gustafson warns Nebraska corn growers to be on the lookout for tar spot. Last year, tar spot showed up late in Nebraska and had no impact on yield — but now that it’s here, growers must be more vigilant.

“Be more observant of tar spot lesions throughout the season,” Gustafson says. “We’re also watching out for southern rust, northern corn leaf blight and gray leaf spot.”
Miravis Neo and Trivapro® fungicides have built a reputation for high performance in the field for control of tar spot and other fungal diseases, he says. As fungicides with exclusive active ingredients ADEPIDYN® or SOLATENOL® technology respectively, Miravis Neo and Trivapro can also help the crop through stressful situations, like drought, by delivering plant-health benefits during grain fill.

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Mid-South Growers: Prep for Aphids, Stink Bugs and Palmer Amaranth

Kentucky and Tennessee

Aphids and Fusarium Head Blight (FHB), the fungal disease also known as head scab, are the pests to watch out for in wheat this year according to Sarah Gehant, Syngenta ASR for Kentucky and western Tennessee.
“CruiserMaxx® brand seed treatment controls fall aphids and should be followed with Warrior II with Zeon Technology® insecticide in the spring,” Gehant says. She advises the importance of controlling aphids all season long, as they can transmit barley yellow dwarf virus in cereals, damaging both yield and quality.

An expanding weed pest in the region is ryegrass. A successful burndown program is critical for getting this weed under control. Gehant recommends an application of Boundary herbicide coupled with Gramoxone® SL 3.0 when going to soybeans or an application of Sequence® herbicide when going to corn or soybeans. Both programs provide residual control, so it is an excellent foundation to setting growers up for success.

Kentucky’s insect to note is stink bugs in soybeans. “Stink bugs were bad last year and we expect it to be worse this year,” she said. “Endigo® ZCX insecticide will do a great job when combined with Miravis Top fungicide at R3.”

Mississippi

Despite its diverse cropping system, which includes cotton, sorghum and rice, soybeans are still the biggest crop to be found in Mississippi, with more than two million acres planted. Palmer amaranth is the big weed to watch out for, according to Tripp Walker, Syngenta ASR in Mississippi.

“The direct weed competition is the biggest issue, because it develops right along with the crop,” he says. “So, we’re trying to avoid those competition-type losses. In a worst-case scenario, failure to manage Palmer amaranth can result in direct crop loss.”

The Mississippi weather promotes disease pressure including frogeye, septoria and target leaf spot in soybeans. Walker says reproductive-stage growth applications of Miravis Top provides good contact and residual control of a host of foliar diseases.

Stink bugs in general, and red banded stink bugs in particular, are at the top of Walker’s insect-threat list for 2024. “Stink bugs feed on the developing seeds, so it is a direct crop loss,” he says. “But the Endigo ZCX premix provides both contact and residual on red banded stink bugs, as well as other stink bugs and insect pests we see in soybeans.”

May 1, 2024 by McKenna Greco

Codling moth can be a nuisance year-round in walnuts, but the worst damage usually occurs as temperatures rise. The sooner it gets warm, the more insect generations that can follow. Control out of the gate goes a long way toward effective, year-long management of codling moth.

The first flight of codling moth usually takes place in spring from the overwintered generation. However, the first two peaks, 1A and 1B, can last several weeks as moths lay first-generation eggs. According to the University of California Integrated Pest Management Program, adult moths can emerge as late as the end of June in the Central Valley and into early July in the state’s coastal areas. Monitoring for infestation and damage can help you make the best treatment decisions for your tree nuts.

A close photo of a codling moth resting on a leaf.
Codling moths can damage your walnut quality and yield potential.

Second and third generation codling moth will start to emerge in June. The key to in-season control is to know what other economically damaging pests are present so you can treat all of them. Using any one product class too long will allow codling moth to develop a tolerance.

The use of Proclaim® insecticide is a good first step in managing the more destructive worms and offering some activity on adults. Proclaim is a Group 6 chemistry, which makes it a solid resistance management partner for other insecticides used later in the season on codling moth. Proclaim also doesn’t wipe out beneficial insects that are present at the same time as codling moth in walnuts.

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May 1, 2024 by McKenna Greco

In the heat of July, almond hulls begin to split open and it’s a prime time for disease to attack. Mid-season, pre-harvest diseases like hull rot can greatly harm your bottom line if left unchecked.

Hull rot is a general term for hull infection by one of several pathogens. Hull rot can be a huge pain in the middle of the season because infected nuts don’t shake off at harvest and require removal by winter sanitation to eliminate

Almonds are susceptible to hull rot fungi from the beginning of hull split until hulls dry – a period that can last from ten days to two months depending on fertilization and irrigation. The infection invades once hull split begins and produces a toxin that kills the spur and shoot attached to the fruit, reducing bearing surface of the tree.

The disease makes it difficult to remove the almond kernel during harvest allowing the infection to harbor in remaining nuts and spread from year-to-year.

Identify Hull Rot

  • Check for a brown area on the outside of the hull and a tan fungal growth in the brown area on the inside or outside of the hull (this indicates Monilinia).
  • Check for a powdery black fungal growth on the inside of the hull (this indicates Rhizopus).

Identification of the specific pathogen (Monilinia or Rhizopus) may help with management for the following growing season, but a proactive, preventative approach will be your best bet in safeguarding your yield.

Prevent Disease During Hull Split

Have the right tools handy can give your trees a boost of protection and a better chance at improving yield. Applying a robust fungicide like Quadris Top® can offer a broad-spectrum control of hull rot and other damaging diseases, and has been shown to provide preventive, systemic and curative control on a wide spectrum of diseases.

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April 30, 2024 by McKenna Greco

Tar spot was first discovered in Midwest corn fields in 2015 and continues to raise alarm bells. Severe cases of tar spot spread may lead to losses of up to 60 bu/A. Stay ahead of tar spot and prevent significant yield loss by frequently scouting your corn fields and developing a thorough disease management plan. Here’s how:

How to Scout for Tar Spot

Tar spot usually appears as raised, circular black spots on corn leaves, stalks and husks. Some other pathogens have similar symptoms, but the University of Minnesota Extension reports that growers can differentiate tar spot by wetting affected parts of plants and rubbing with their fingers. Unlike other diseases, tar spot will not rub off.

Tar spot has a long latent period, so corn can be infected and begin causing costly damage 14 days or more before you see it in your fields. Start early and scout frequently until silage to stay ahead of the disease and avoid late season losses.

Why Tar Spot Thrives in the Midwest

If tar spot wasn’t a problem last year, it might not be on your radar. However, tar spot thrives in the Midwest climate due to the cooler temperatures and high relative humidity. Increased potential rainfall can increase disease severity and lead to substantial yield loss if you’re unprepared.

To complicate matters further, tar spot overwinters and has spread rapidly since 2015. If tar spot was confirmed in neighboring states or counties, be on guard this year. Pay attention to the forecast and be prepared to pivot depending on tar spot pressure.

What to Know About Potential Yield Loss

Yield loss of 30 to 40 bu/A is common and can be even greater when corn is infected early in the season. But don’t let your guard down later in the season either — even at full-dent, tar spot can cause losses of up to 20%.

Tar spot can have long-term implications as well. Although only 20 to 25% of overwintering spores will survive, even just a few spores can cause significant damage. Under the right conditions, tar spot can produce millions of spores.

How to Manage Tar Spot

It’s tempting to save on input costs, but the possible damage and potential yield loss from tar spot isn’t worth it. Trials show that preventive fungicide applications are significantly more effective than curative applications against tar spot.

Tar spot isn’t the only threat to your corn crops. Other yield-robbing diseases like Northern corn leaf blight and gray leaf spot continue to threaten crops. Prioritize protecting your yields and ROI from a variety of corn diseases with a broad-spectrum plant-health fungicide like Miravis® Neo and Trivapro®.

Long-lasting disease protection is key to managing tar spot. Miravis Neo and Trivapro contain ADEPIDYN® and SOLATENOL® technology for powerful and more long-lasting protection against disease and environmental stress.

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April 11, 2024 by McKenna Greco

To spray or not to spray? It’s the age-old question all growers face: is spraying a fungicide worth it? Local weather conditions and disease pressure factor into the yearly debate of whether or not to spray. But the question shouldn’t be if it’s worth spraying a fungicide, but if you can afford not to.

A map showing improved corn yields under wet and dry conditions with Miravis Neo and Trivapro fungicides from 2020 and 2021

In the last five years, 2020 was the driest summer and 2021 was the wettest. In both scenarios, Syngenta Cleaner & Greener fungicides showed excellent performance and improved corn yields over untreated acres. In the dry conditions of 2020, Miravis® Neo and Trivapro® fungicides delivered an average 14.1 bu/A yield increase over untreated; and in the wet, tar spot-heavy conditions of 2021, they delivered an average 17.2 bu/A increase over untreated1. The data also shows a 6.8 to 7.8 bu/A yield advantage in soybeans treated with Miravis Neo or Miravis Top compared to untreated acres2.

A map showing improved soybean yields under wet and dry conditions with Miravis Neo and Miravis Top fungicides from 2020 and 2021

By choosing a fungicide with both exceptional disease control and proven plant-health benefits, you can expect stronger, healthier plants – even under drought conditions. Why? It all comes down to three pillars: light absorption, water conservation and harvest efficiency. Syngenta technical product lead Tyler Harp explains how these add up to healthier plants and higher yield potential.

  1. Light Absorption:  Leaves that are greener can capture more light energy from the sun and focus more energy to money-making yield.
  2. Water conservation: Better water conservation with plant-health fungicides means a lower transpiration rate in the leaves, minimized water vapor loss in the crop, better moisture retention and a more efficient use of water, which is key in a drought.
  3. Harvest Efficiency: With fungicides that control disease and help preserve crop strength, there is less lodging and shattering at harvest. “This allows growers to conduct their harvest more quickly, saving time, fuel and ultimately money.

Together, improved water conservation, light absorption and harvest efficiency promote a healthier crop with maximized grain fill and yield potential.

Want to learn more about how Cleaner & Greener fungicides work? Watch as Harp and Syngenta product lead Logan Romines explain the bushel-boosting science behind the Syngenta fungicide portfolio.

Interested in how Cleaner & Greener fungicides can help preserve your yield potential? Visit BoostYourBushels.com to explore trials and calculate your ROI.

1 Syngenta on-farm, large strip trials. 2020 trial locations: IA (2), IL (33), IN (6), NE (6), OH (13), WI (11) and SD (26). 2021 trial locations: IL (35), IN (9), WI (7) and SD (13).

2 Syngenta on-farm, large strip trials. 2020 trial locations: IA (5), IL (29), IN (6), OH (10), WI (17) and SD (15). 2021 trial locations: IL (25), IN (1), WI (3) and SD (2).

April 11, 2024 by McKenna Greco

We’ve all heard it before: Timing is everything, and it couldn’t be more true when considering when to make a fungicide application. Fluctuating weather conditions, commodity prices and disease severity complicate the timing decision, but now we know that timely applications of Syngenta plant-health fungicides are one of the best ways to consistently preserve yield potential under both disease conditions and environmental stressors like heat or drought. The steady increase in the number of corn and soybean growers that choose to apply a fungicide is evidence of the value fungicides deliver.

Prepare for Familiar Foes and Emerging Threats

Northern corn leaf blight, Southern rust, tar spot and gray leaf spot have earned their reputation as devastating corn diseases, and white mold, brown spot and frogeye leaf spot are known to decimate soybean fields.

These well-known threats pack a serious punch. Southern rust, a familiar foe to corn growers primarily in Southern states, can cause yield losses of up to 100 bu/A, according to the University of Florida IFAS. Meanwhile, researchers at South Dakota State University determined that white mold can cause soybean yield losses of over 40% depending on the infected growth stage. Corn growers also contend with emerging threats like tar spot, which has caused yield losses ranging from 20-80% since its discovery in the U.S. in 2015.

To better protect your fields from disease threats, timing is crucial when making your fungicide application to make sure you are getting the most value from your fungicides.

Spray When Disease Impacts Yields

Apply too early, and corn and soybeans are left vulnerable to late-season disease. Apply too late, and susceptible crops might not be able to recover from the onslaught of disease or environmental stress. Even worse, the wrong fungicide at the wrong time can negatively impact corn’s health, leaving it more susceptible to disease and providing little disease protection.

For both corn and soybeans, the optimal fungicide application window is centered around critical growth periods when disease has the greatest potential to impact yields.

Corn Application Timing

The largest yield reduction occurs at R1, when corn is fully tasseled, beginning to green silk and under stress. Foliar fungicides applied at tasseling or early silking (VT-R1) provide optimal disease control by preventing disease onset when corn is most susceptible to stress. VT-R1 applications deliver better overall disease control, stalk integrity and harvest efficiency. Applications at this crucial stage in development are most likely to see a yield response and provide significant value to your bottom line.

An illustration of a corn plant depicting the ideal VT-R1 fungicide application timing
Corn fungicide applications between VT-R1 help combat environmental stress, disease and ultimately yield reduction.

Soybean Application Timing

For most foliar soybean diseases, including frogeye leaf spot and brown spot, the ideal fungicide application window is at the R3 or “beginning pod” stage. The R3 growth stage occurs when the pod is 3/16” long at one of the four uppermost nodes of a main stem with a fully developed leaf. Foliar fungicides applied at this stage have the greatest impact on yield preservation because disease severity is beginning to rapidly increase and stress in the following R4-R6 stages can cause severe reductions in yield.

However, fields with a history of white mold might require an earlier application, especially if extended periods of cool weather are on the forecast. In this case, consider applying a fungicide at early bloom to late bloom. By the time you see widespread symptoms in the field, it will be too late to manage white mold effectively.

Choose the Right Fungicide

To help get the most out of your fungicide application, choose a product with a long-lasting residual to make sure your crops are protected between application and potential disease onset. Early applications of fungicides without a strong residual may only delay disease onset and ultimately still open the door for late-season losses.

That’s why we recommend Miravis® Neo corn and soybean fungicide and Trivapro® corn fungicide. Miravis Neo and Trivapro both provide long-lasting residual control as well as broad-spectrum preventive and curative disease control. The enhanced application flexibility and long-lasting residual help protect yield potential from application to harvest.

Reap the Rewards of Cleaner & Greener Fungicides

Both Miravis Neo and Trivapro fungicides do more than protect against disease. With the right application timing, they also provide plant health benefits to preserve yield potential, even in years with low disease pressure.

For corn and soybeans, these benefits include:

  • Improved water conservation.
  • Increased light absorption.
  • Improved CO2 assimilation and nitrogen utilization.
  • More efficient harvest.

These benefits translate to healthier, more productive crops by shifting energy away from fighting disease and environmental stress and toward growth and grain fill. Whether you are battling heavy disease pressure or drought conditions, these fungicides can provide consistent yield preservation.

Trial data shows that Miravis Neo and Trivapro fungicides delivered yield increases to corn and soybean fields over untreated in both the drought conditions of 2020 and the wet, tar-spot heavy conditions of 2021.

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