2024 Corn Hybrid Performance Trials Results

Nicole Fiorellino | nfiorell@umd.edu
Assistant Professor & Extension Specialist, Agronomy

The 2024 Maryland Corn Hybrid Trials results can be found at https://psla.umd.edu/extension/md-crops or downloaded at the link below. Many thanks to Louis Thorne, Gene Hahn, and Audrey Sultenfuss for their time spent preparing, establishing, collecting data, and preparing the report. These trials could not be completed without them. I greatly appreciate the Center managers and personnel who assist our team with executing these trials.

We are grateful for the funding provided by Maryland Grain Producers Utilization Board to support these trials. MGPUB provides our program with checkoff funding to support applied agricultural research and so we may generate results that directly benefit Maryland producers.

Download the 2024 Corn Hybrid Trials Report here

Maryland Regional Crop Reports: September 2024

Reports are for crop conditions up to September 5, 2024.

Western Maryland

August brought us more rain than June and July combined. The hay and pasture fields responded, and there is hope for continued grazing and another cutting. The soybeans are probably the greatest beneficiary of the moisture. They are looking great as their pods fill. Modern varieties are a wonder to behold. Corn silage harvest began earlier this year thanks to the heat and drought. Many folks are glad they planted a little extra corn, primarily due to the need for forage and the low grain price forecast. Running it through livestock will add value. Triticale and oats are going in the ground for both fall and spring forage. Cool mornings and mild days have raised our countenance here in Western Maryland.—Jeff Semler, Washington Co.

Central Maryland 

August has finally brought some much needed rain; although amounts have been scattered throughout the region. A storm last week caused crop damage in some areas of the region. While it won’t be a year for record-breaking yields, most of the corn and soybeans are looking fairly good. The majority of corn is in the dent stage and is starting to dry down. Silage chopping has begun. Full season soybeans are in the beginning seed stage (R5).—Kelly Nichols, Montgomery Co.

Northern Maryland

About 6” of rain fell in August, which really woke up soybeans, especially later planted beans and double crops. Unfortunately, the rains have ceased, with the last measurable rainfall coming over two weeks ago. Rain is predicted for this weekend, so fingers crossed for good rainfall to finish out what could be a strong late season bean crop. Corn is rapidly drying down and a few acres have been harvested but the majority of corn is still 25% moisture or better. We are about another 10-14 days before the combines are rolling hard. Tar spot was also confirmed in the region at the end of August, consistent with the two years prior. A lot of good dry hay was put up over the last two weeks.—Andy Kness, Harford Co.

Upper and Mid Shore

July’s much-needed rains tapered off, leaving August with sporadic showers that varied significantly depending on your neck of the woods. This inconsistency has led to some challenging conditions for crops. Signs of water stress have become apparent; soybean leaves are cupping and corn leaves are curling from lack of moisture. In response, center pivots on irrigated fields have been fired up again, helping to maximize yield potential after a brief respite in July. Corn is drying down, with some early-planted fields already harvested. Soybeans are also moving along, with early maturing varieties starting to turn and double crop beans filling out their pods. The dry conditions earlier in the season provided the perfect environment for Palmer amaranth to thrive and compete with the crops. They can clearly be seen towering over the soybean and even corn in both conventional and organic fields. The region has also noticed more spotted lanternfly activity as these pests hit their final growth stage and take to the air. While they’re mostly just a nuisance in agronomic crops, controlling them can really help out your local fruit and vegetable grower, who would surely appreciate the effort.—Dwayne Joseph, Kent Co.

Lower Shore

Corn is drying down, but harvest has not yet begun. Due to low grain prices, farmers are inclined to let corn completely dry in the field, rather than take a moisture price hit at the mills. Drought stress during vegetative and early reproductive phases hurt corn. Yield is anticipated to be poor, and ears look small. Soybean is looking better than corn, especially double-crop soybean planted after wheat. There have not been reports of serious pest or weed damage. Cover crops are being flown into some corn fields via airplane.—Sarah Hirsh, Somerset Co.

Southern Maryland

Conditions remain very dry across the majority of Southern Maryland. Corn harvest is in full swing with reports of average to well below average yields. Yields vary greatly within and between fields depending on soil type and where isolated showers happened to fall. Grain quality is a major concern this year. Growers are encouraged to get corn off as early as possible. Beans continue to put up the good fight. Many full season beans are yellowing and drying down. Double crop beans will need some more help to fill out pods. Farmers have been scouting for pod worms and stink bugs. Thankfully, only a few fields have reached threshold and required a treatment so far. Weeds continue to require attention as fields have taken longer to canopy if at all, allowing greater opportunity for weeds to gain their share of the limelight. We continue to see ragweed, pigweeds of all types, and morning glory present. Deer damage is readily apparent in later planted beans that are failing to re-grow or canopy following deer feeding. Forages have struggled this summer with many fields of cool season grasses requiring replanting this fall or next spring.—Ben Beale, St. Mary’s Co.

*Regions (counties):
Western: Garrett, Allegany, Washington. Central: Frederick, Montgomery, Howard. Northern: Harford, Baltimore, Carroll. Upper & Mid Shore: Cecil, Kent, Caroline, Queen Anne, Talbot. Lower Shore: Dorchester, Somerset, Wicomico. Southern: St. Mary’s, Anne Arundel, Charles, Calvert, Prince George’s

Tar Spot Update: First Reports for 2024

Andrew Kness, Senior Agriculture Agent | akness@umd.edu
University of Maryland Extension, Harford County

Figure 1. Map of tar spot of corn for 2024 growing season as of September 5.

Our first official reports of tar spot have been confirmed in Maryland for 2024; almost exactly on pace for when we first detected tar spot in 2023 and 2022. The first report came from a dent corn field in Baltimore County on August 22 and subsequent reports were made from fields in Harford County on August 27 and September 4. All of these fields are near black layer and yield loss due to tar spot infection is not likely unless infection occurred earlier in grain fill or during pollination. It is not likely that we had tar spot infections occurring in July due to the extreme heat this year. Tar spot infections require lower temperatures than other common fungal diseases of corn such as gray leaf spot.

As average daily temperatures begin to dip into the mid 70s and mid 60s, tar spot symptoms will likely start to flare up in corn. Tar spot can spread as long as there is green tissue on the plant, which means symptoms can worsen even past black layer, making for a field that could look far worse than it actually is. For reference, last fall I did yield checks in two corn fields and one research plot that had fairly moderate levels of tar spot infection (Figure 2) but still yielded very well (220-300 bu/a), with the field with the worst symptoms topping 300 bushels. What likely happened is tar spot infected corn close to R5-R6 and it continued to spread after black layer since the plants stayed green beyond physiological maturity due to the stay green effect of foliar fungicides that were applied to these fields. Even though tar spot spores can blow short distances in the wind, if you are harvesting a field infected with tar spot, it would be a good practice to try to clean as much corn fodder off of equipment prior to moving to a new farm; a blower or air compressor will do the trick.

Figure 2. Tar spot symptoms on a senesced corn leaf.

As you are scouting your corn fields, be on the lookout for tar spot. With funding from the Maryland Grain Producers Utilization Board, we are conducting a survey of the distribution of tar spot in Maryland. If you have tar spot, or think you might, please report it to corn.ipmpipe.org or reach out to me at akness@umd.edu or (410) 638-3255. Reports are kept anonymous and individuals and/or farms are not identified in any reports, publications, or communications.

Ear and Stalk Rots May be an Issue in Corn

Andrew Kness, Senior Agriculture Agent | akness@umd.edu
University of Maryland Extension, Harford County

stalk and ear rot of corn
Stalk rot (left) and ear rot (right) of corn.

With the dry then wet (then dry again) weather pattern we had this year, corn went through a lot of stress. Stressed corn is much more susceptible to ear rots and stalk rots. The degree of severity is dependent on a variety of factors, so it is wise to scout fields prior to harvesting in order to identify problematic fields and give them harvest priority.

Several different pathogens can cause ear rots in Maryland; the main contenders are listed in the table below. Although they typically do not affect yield, they can cause grain quality issues through the production of mycotoxins. Furthermore, if infected grain is not dried quickly or to a low enough moisture content, infection can spread, even when in the bin. Therefore, it is important to scout and identify fields that are infected with ear rots and harvest those first. It is better to pay a few cents in propane to dry the wet grain than to wait and risk infection levels getting worse, and the potential for elevated mycotoxin concentration in the grain. Quickly dry infected grain to 15% for short-term storage and to below 13% for long term storage and it is not recommended to store infected grain for longer than a year. It is important to note that not all ear rotting fungi produce mycotoxins, so I would recommend working with your Extension agent or crop advisor to get proper identification so that you know the species in question and thus if mycotoxin contamination is a concern.

Table 1. Common ear rots of corn.

Disease Pathogen Symptoms (see next page for pictures) Mycotoxin
Fusarium ear rot Fusarium verticillioides “Starburst” kernels, white kernels, infected kernels may be scattered on ear Fumosin
Gibberella ear rot Fusarium graminearum Ear covered in white mat often with pink hue, infection starts at tip and can progress to butt end of ear Vomitoxin (DON)
Diplodia ear rot Stenocarpella maydis and S. macrospora White fungal mat on ear, may cover the entire ear None
Penicillium ear rot Several Penicillium species Blue-grey spores on kernels developing on damaged ears (hail, deer feeding, insects, birds, etc.), may infect the germ of the kernel Some species may produce mycotoxins
Trichoderma ear rot Trichoderma viride Green spores in between kernels None
Aspergillus ear rot Aspergillus flavus Olive green spores on ear, usually starting at tip, associated with damaged ears (feeding from insects, deer, birds, etc.) Aflatoxin

Stalk rots are also a harvest concern. Like ear rots, stalk rots are also caused by many different pathogens, several of which are listed in Table 2 below. No single factor causes stalk rots; they are rather the end result of a host of factors that contribute to a net deficit in plant carbohydrates needed for grain fill. The grain fill process is a major carbohydrate sink for the plant. As the plant produces carbohydrates through photosynthesis, it allocates almost all of it’s carbohydrate production to filling the kernels. A healthy plant will have sufficient leaf area to maximize photosynthesis and can therefore produce enough carbohydrates to fill the grain. However, when photosynthetic leaf area is compromised, the plant cannot make enough food to fill the kernels. In order to compensate for the deficit, the plant cannibalizes carbohydrates from existing tissues. The first tissues to go are the stalks, which are then easily compromised by stalk-rotting pathogens. Stalk rot is a byproduct of stressed plants during the growing season, particularly during grain fill.

Table 2. Common stalk rots of corn.

Disease Pathogen
Anthracnose stalk rot Colletotrichum graminicola
Diplodia stalk rot Stenocarpella maydis
Charcoal rot Macrophpmina phaseolina
Gibberella stalk rot Fusarium graminearum
Fusarium stalk rot Multiple Fusarium species

Any factor that reduces leaf area or reduces photosynthesis after pollination will predispose plants to stalk rots. These include reduced leaf area through insect feeding, lesions from foliar diseases, or mechanical damage (such as hail). Other factors include inadequate fertility, water stress, and excessive plant populations. Another significant factor is hybrid genetics; both resistance ratings to stalk rotting pathogens as well as ear and kernel size. High-yielding, large kernel hybrids are more susceptible to stalk rots if they are not kept healthy through grain fill.

Scout fields for stalk rots as early as black layer. The “pinch test” is one way to scout for stalk rots. Pinch the stalk in between the nodes at one of the lower two nodes. You should not be able to pinch healthy stalks, but rotted stalks will fairly easily collapse. Do this at several random locations to assess the field. Alternatively, you can do a “push test,” which involves pushing the corn stalks approximately 30 degrees from horizontal (8 inches laterally) at a height of about eye level. Healthy stalks will return to vertical while infected plants will not. If more than 10% of plants tested exhibit stalk rot symptoms, you may want to harvest as soon as possible or risk a not-so-fun harvest of lodged corn.

New Ecological Mitigation Menus to Reduce Pesticide Runoff

Kurt Vollmer, Weed Management Specialist | kvollmer@umd.edu
University of Maryland Extension

Pesticide runoff can occur when pesticides are carried by water off an application site. This usually occurs when water is applied to the soil faster than it can be absorbed, resulting in excess water flow across the land. Pesticide runoff into streams can pose risks to aquatic life, fish-eating wildlife, drinking water, etc. Therefore, new ecological mitigation requirements are being added to certain pesticide labels to reduce pesticide runoff.

What is the purpose of these new runoff mitigations?

These measures are designed to reduce pesticide movement out of a treated field. These practices are part of a wider strategy to protect endangered and non-target species, and will be part of future pesticide registration decisions.

Will these new runoff mitigation requirements be applicable to all pesticides?

No, only the application of certain pesticides will require these measures be implemented. Check the pesticide label for a section dedicated to runoff/erosion mitigation.

What do I do if I plan to spray a pesticide with one of these new mitigation requirements?

First, determine whether the application area is in a county designated as having high runoff vulnerability. The EPA has classified all counties on the Eastern Shore of Maryland and Delaware, as well as Anne Arundel, Charles, and St. Mary’s counties as having high runoff vulnerability. Initially, only applications to fields in these counties will require additional mitigation.

Are there exemptions for implementing these mitigations?

Yes, additional mitigation will not be required in counties with high runoff vulnerability if any one of the following criteria are met during an application:

  • the soil texture is comprised of over 50% sand, a loamy sand, or sandy loam soil;
  • the application area has a slope of ≤ 3%, or has a perimeter berm system;
  • the application is a partial field treatment, such as a banded or spot spray application;
  • the pesticide is incorporated into the soil mechanically or via irrigation; and
  • the treated field has subsurface or tile drains installed with controlled drainage.

My application area does not meet any of the aforementioned criteria. Now what?

Visit https://www.epa.gov/pesticides/mitigation-menu for a list of options. Even if additional mitigation is required, several EPA accepted practices have already been adopted in the area, such as reduced or no tillage, and the use of cover cropping.

Maryland Regional Crop Reports: August 2024

Reports are for crop conditions up to August 1, 2024.

Western Maryland

Welcome rains have sporadically arrived in Washington County. This has been the story for much of the summer. It depends on your location and how much rain you receive, out of which storms. Earlier in the spring, the southern part of the county was blessed more than the part that hugs the Mason-Dixon Line. July has seen that trend nearly turned on its head. Wheat is off, and test weights and yields were good. Many acres of optimistic double-crop beans were planted again. Moisture has dictated the success of those plantings. It is too soon to make any predictions on corn yields, but in many places, plants are shorter, but the ears might fill just fine. So we wait. In two weeks, choppers will start running, and corn silage will be our first indicator of yields. Peach harvest started a little early, and they are smaller, and yields are lower, but they are sweet.—Jeff Semler, Washington Co.

Central Maryland 

Corn and soybeans are well into reproductive stages and further along than previous years. Most of the region has experienced drought conditions throughout the growing season. Some growers have begun chopping early corn silage given how far hot dry weather has pushed the crop. Very limited disease pressure throughout the region. Recent rains have been welcomed, where received. Most precipitation events have been sporadically distributed to say the least.—Mark Townsend, Frederick Co.

Northern Maryland

We ended July with around 3” of rain here at the Harford County Extension office. Rains were more periodic in July; however, that is not the case for the entire region—rains continue to be scarce the further west into Baltimore and Carroll County you go and the rain that has fallen across our region has been very scattered and localized. You can find corn that looks very good and you can find corn that looks very poor all in the same county. I do believe that most places are “holding on” in terms of yield—I think we will fare OK and we may have avoided a complete disaster but corn yields will certainly be off of our norm. Soybeans are flowering and look good; if they can fill all the pods they’re initiating then soybean yields should be strong; the next few weeks will make or break them.—Andy Kness, Harford Co.

Upper and Mid Shore

The first couple of weeks in July brought us more of the high temperatures we’ve been experiencing, but unlike June, we were finally blessed with some much-needed rain across the region. While some areas received more rain than others, it was all welcome. The timing couldn’t have been better, as most of the corn was entering the reproductive stages right at the start of the month. Due to this, late-planted corn is likely to yield better than the earlier-planted corn. Both full-season soybeans and corn are now in their reproductive stages. Most of the corn has finished pollination and is moving into kernel development. On the small grains front, yields were either on par with or lower than last year, with not many reports of fields outdoing last year’s yields. The recent rains have also triggered a flush of weeds. If you look out over the soybean canopy, you’ll see those notorious pigweeds, common lambsquarters, morningglories, and annual grasses making an appearance, especially in the lesser-managed fields.—Dwayne Joseph, Kent

Lower Shore

We have had periodic rains the last few weeks and much of the drought damaged corn is greening up. Farmers are optimistic that the corn will pull through and have average yields. The later planted corn the better, in terms of less drought damage. Most corn is now in reproductive stages. Some corn is being aerially sprayed with fungicides. Milo is heading out. Soybean also faced drought damage, but is looking good with the recent rains. Double crop beans are starting to take off with growth. Substantial weed or pest pressure has not been reported..—Sarah Hirsh, Somerset Co.

Southern Maryland

The region is finally getting some relief from the hot dry conditions we have experienced since June. Rain showers have been scattered, so some areas are better off than others. Unfortunately, some of the rains have come a bit late for corn which was past pollination. For the conditions this year, the crop overall looks much better than should be expected. Soybeans follow much of the same story. Many full season beans could never get off the ground with a lack of moisture and constant deer predation. These plants are now trying to canopy and flower but are way behind schedule for this time of year. Weeds, especially annual grasses, marestail, Palmer amaranth and common ragweed have taken advantage of the extra sunlight and lack of canopy closure to germinate. Many fields are speckled with these weeds coming in later in the season.  Double crops beans struggled to germinate in the dry conditions or were planted late. They have made good strides in the last couple of weeks. Vegetable crops are coming off now with a consolidated harvest season due to the hot temperatures as of late squeezing the harvest window.—Ben Beale, St. Mary’s Co.

*Regions (counties):
Western: Garrett, Allegany, Washington. Central: Frederick, Montgomery, Howard. Northern: Harford, Baltimore, Carroll. Upper & Mid Shore: Cecil, Kent, Caroline, Queen Anne, Talbot. Lower Shore: Dorchester, Somerset, Wicomico. Southern: St. Mary’s, Anne Arundel, Charles, Calvert, Prince George’s

Podworms in Soybeans

Emily Zobel, Senior Agriculture Agent Associate | ezobel@umd.edu
University of Maryland Extension, Dorchester County

The second generation of corn earworms/podworms/headworms (Helicoverpa zea Boddie, Figure 1) will soon emerge from corn fields and other crops. On soybeans, the podworms may feed on foliage, flowers, and fruit. Female moths will lay eggs over the entire plant, but caterpillars prefer to feed on tender vegetative terminals and/or flower clusters. Fields in bloom to pod-set stage with an open canopy and stressed soybeans during this second-generation flight typically reach the highest populations and are at the most risk. Due to our early summer weather this year, more fields might be at risk compared to last year. Podworm populations can be spotty, so one field may have high podworm populations while the field next to it may have low podworm populations. The only way to know what is happening in a particular field is to sample it. You can sample pod worms using either a sweep net or drop cloth.

Figure 1. Corn earworm/soybean podworm moths are robust, light brownish-tan with a 1” to 1 1/2” wingspan. They have a prominent dark spot on each forewing. They tend to be active during the evening and dark hours but can be commonly seen in fields during the day. Photo by Ronald Smith, Auburn University, Bugwood.org.

Thresholds are generally around 2-3 worms per 15 sweeps. NC State University (NCSU) has a nice podworm threshold calculator that helps you customize your threshold based on treatment cost, row width, and price of the bean into consideration: https://bit.ly/NCSUwormthershold. Davis Owen, Delaware Extension Entomologist, recommended applying Besiege or Elevest at their low rates last year to control soybean podworms. Pyrethroids are not guaranteed to provide good efficacy.

Even though fields in the bloom stage are at risk for high populations of podworms, it is generally recommended not to spray during this stage and instead wait for the end of flowering or early pod set to treat. Soybean plants produce more flowers than they can convert into pods. A study conducted by NCSU has found that soybean plants can compensate for this loss of flowers due to caterpillar feeding damage. No yield losses were recorded even with caterpillar levels three times higher than the economic threshold for podding-stage soybeans. Also, young caterpillars tend to have a high mortality rate. They are often difficult to reach with chemical controls while feeding within flower clusters.

Continue to scout during pod growth and fill, as serious yield loss can occur when large caterpillars coincide with soybean seeds that have achieved almost full size.

Reporting Tar Spot

Andrew Kness, Senior Agriculture Agent | akness@umd.edu
University of Maryland Extension, Harford County

Figure 1. Images of tar spot on corn leaves. Images: A. Kness, Univ. of Maryland

As you are scouting your corn fields, be on the lookout for tar spot. With funding from the Maryland Grain Producers Utilization Board, we are conducting a survey of tar spot’s distribution in Maryland. If you have tar spot, or think you might, please report it to corn.ipmpipe.org or reach out to me at akness@umd.edu or (410) 638-3255. Reports are kept anonymous and individuals and/or farms are not identified in any public reports or publications.

Fall Forage: Playing Catch-Up

Jeff Semler, Principal Agriculture Agent | jsemler@umd.edu
University of Maryland Extension, Washington County

As of this writing, most of Maryland’s conditions range from abnormally dry to a small portion of severe drought. Recent sporadic rains have renewed the optimism inherent in every farmer, but we need to look ahead and plan.

Whether you are involved in animal agriculture or your neighbor is, forage will be short this year. How can we mitigate this situation? First, if you are a corn grower, with corn hovering at four dollars a bushel, you should consider selling the crop as silage. I have little doubt many of your neighbors would appreciate the opportunity.

This gives you options for planting cover crops earlier that could be harvested and sold as forage this fall or next spring. You could also get your cover crops in earlier and reap the benefits next spring as you plant your next crop. Cover crops are no longer a novelty or experiment. They are a proven soil builder.

Fall forage comes in many options. It can be as simple as oats. If you can plant early, then forage oats are your best choice, but if you plant later, grain oats will mature faster and give you more bang for your buck.

Preferably, you think a bit longer term. Planting oats with companions like triticale, wheat, barley, rye, annual ryegrass, and crimson clover will give you forage this fall and next spring. I am a big fan of triticale, which provides you with quality and a wider harvest window. That said, use what works for you.

I would be remiss if I didn’t caution you regarding annual ryegrass. This species can become a weed. Many wheat growers have rued the day they planted annual ryegrass on their farm. There is also evidence that it is becoming glyphosate-resistant, so you have been warned.

For those unsure of forage needs in the spring, barley or wheat are excellent choices for fall oat companions. If you don’t need the forage, you can harvest all or part of it for grain.

Adding legume, be it a clover or vetch, makes sense on multiple levels. Adds protein forage and nitrogen to the soil.

In short, plan ahead when considering your forage needs and options.