Reports are for crop conditions up to July 5, 2024.
Western Maryland
Dry, dry, dry. The pleasant spring has turned into a dry summer so far. Even when the heat isn’t oppressive, the sun is bright, and the wind blows all wonderful conditions for drying out things. Corn and full-season bean planting is a memory. Wheat harvest is in full swing, and yields and test weights are good. Two cuttings of alfalfa are off, and we are hoping for enough moisture to make a third cutting. Double-crop beans are going in the ground, further proving that farmers are the most optimistic people on the planet. Until next month, keep looking up. One day, those clouds will have rain in them, and we will need it.—Jeff Semler, Washington Co.
Central Maryland
The wet spring resulted in lots of slugs and replanted soybeans. However, in the last few weeks, the rain has disappeared here in Montgomery County. Temperatures have soared into the upper 90s, resulting in some very dry topsoil, subsoil which is quickly losing moisture, and drought-stressed crops. Some corn fields are starting to tassel, and soybeans are beginning to flower.—Kelly Nichols, Montgomery Co.
Northern Maryland
June was unusually dry and we are in a drought situation. Wheat and barley harvest and straw baling was a breeze to the dry weather, and harvest came about 1-2 weeks earlier than normal due to the dry, windy June. Yields were not near the record-setting numbers we’ve seen the past two years but they were still respectable. Having small grains off early will greatly benefit double-crop soybeans, assuming there’s enough moisture in the ground to germinate them. Earliest planted corn is in tassel by July 4 and we thankfully got a couple of decent storms just as tassels were pushing through and alleviated drought scenarios in many fields; that rain likely saved several bushels. Full season soybeans are also starting to come along nicely now after a slow start that some moisture is back in the soil.—Andy Kness, Harford Co.
Upper and Mid Shore
Center pivots have been working double time, keeping corn and soybean fields in the region irrigated amid the ongoing dry spell. Significant rain events are a distant memory, and the summer solstice has brought record heat, contributing to visible water stress symptoms on non-irrigated fields. All corn acres are planted, and early-planted corn is currently tasseling. Small grain harvest is progressing well, aided by the dry weather, which has extended the harvest window. As the small grain harvest wraps up, double-crop beans will soon be planted. Meanwhile, sprayers are busy applying post-emergence herbicides to fields to manage pre-emergence weed escapes, most likely due to the absence of an activating rain. Hopefully we get some rainfall soon.—Dwayne Joseph, Kent Co.
Lower Shore
We had a very dry couple of weeks. Crops were showing signs of drought stress with stunting and leaf burning in some fields. This was followed by a 2-4” rain event across much of the Lower Shore. Corn is approaching late vegetative stages, but not yet tasseling. Wheat has been harvested and double crop soybean planted.—Sarah Hirsh, Somerset Co.
Nicole Fiorellino, Assistant Professor & Extension Agronomist | nfiorell@umd.edu University of Maryland, College Park
With the recent dry weather, some corn sidedress applications have been delayed past the optimum application window, causing farmers to think about the necessity of a “late” sidedress application. Let’s discuss corn growth stages and nitrogen (N) utilization in the plant and summarize research findings of yield response to “late” sidedress applications. This information can be useful for farmers to decide how to make decisions based on profitability, which sometimes may mean foregoing a late application which may result in decreased yields.
What is the “short stave”?
I often quote Liebig’s Law of Minimum and the visual analogy of a barrel made of wooden staves to represent agronomic management decisions, specifically fertility decisions. The first step to correcting a growth problem, be it fertility or otherwise, is identifying the problem that must be corrected – determining the “short stave” of the barrel limiting its capacity. While the gut reaction to stunted corn that missed a sidedress application may be a N deficiency, the “short stave” could be dry soils. I have seen corn that visually improved this week just due to precipitation. If you have heavier soils, good organic matter, maybe used manure, your corn may improve as the soil is rewetted and some N in the soil makes its way to the plant, eliminating the need for a trip across the field. Further, a rushed N application without precipitation in the forecast is not useful, as the N will not reach the plant roots with water as its vehicle.
Defining a “late” application
Each farmer may have a different definition of “late” sidedress application, so we should clarify this term and translate it to corn growth stages. Corn sidedress application is recommended between V4 and V6, to provide N to the corn as it enters a rapid uptake phase through the rest of the vegetative growth stage, as depicted in Figure 1. As the plant tassels and enters reproductive growth, the plant shifts from soil N uptake to translocation of N stored within plant tissues to the grain [1]. Thus, VT is the “turning point”, where a sidedress application between V6 and VT could be characterized as “late” but one might categorize any application after R1 as “the point of no return.” Confirming the growth stage of your corn is an important point to consider when weighing the possibility of a late sidedress application.
Figure 1. Nitrogen utilization of corn crop by plant tissue across the growing season. Source: Iowa State University Extension.
Risks of a late sidedress
Beyond missing the optimum window of utilization of applied N by the corn plant, there are other risks to consider when weighing a late application. Taller corn with more canopy coverage runs the risk of physical damage to the corn as application equipment moves through the field. There is the risk of leaf burn with foliar product applied, although the use of drop nozzles could help minimize this. Moreover, the delayed application of N may have stressed the corn in the early growth stages, already decreasing your corn’s yield potential. This means that even with perfect conditions and unlimited nutrients moving forward in the growing season, the yield “ceiling” has already been lowered. So, the cost of an additional N application will not be realized in profit (increased yield) and the most profitable decision may to forego applying more nitrogen. Finally, no farmer wants to risk making an N application when there is potential for loss to the atmosphere or to nearby surface water. Including potential off-site losses of applied N not utilized by the crop into the decision-making process may help make a late application decision more clear.
Yield impacts with late sidedress – pre-tassel
Yield benefits with sidedress through late vegetative growth compared to no application has been observed in other areas of the country; with researchers at Purdue University demonstrating sidedress at V15 and even up to R1 showed improved corn yield compared to no sidedress application, but still significantly less than corn sidedressed at V4 or V6 [2,3]. Research performed at Ohio State demonstrated an N application up to V10 minimized yield loss [4] and results from Cornell indicated significantly decreased corn yield with sidedress at V10 compared to sidedress at V4, V6, or V8 but significantly better than corn yield with no sidedress application [5]. In Minnesota, where the growing season is shorter, a sidedress application at V12 did not result in increased corn yield compared to no sidedress or sidedress prior to V8, with the researcher attributing this to compromised yield potential from early season N deficiency [6]. While these data are not local, they illustrate the potential for rescuing a corn crop from total loss with a sidedress application while the corn is still in the vegetative growth stage.
Yield impacts with late sidedress – post-tassel
Limited research findings exist to evaluate corn yield response to N application post-tassel [7]. There is a potential for rescue with a post-tassel sidedress application where severe N deficiency is observed, but this decision should be balanced with the potential return [6]. The lack of research findings of a post-tassel sidedress application should indicate this practice may not be recommended to optimize corn yield, farmer profitability, or environmental benefits.
Conclusions
Multiple factors should be considered when weighing a late sidedress application, first, determining the “short stave” and considering it could be drought, not N deficiency, and second, confirming the growth stage of the corn. While there are risks associated with late sidedress application, namely physical damage to corn with application equipment or increased potential for N loss off-site, data support sidedress application up to the end of vegetative growth can result in corn yield between optimum sidedress application and no sidedress application. There is no research to support yield benefits with sidedress applications post-tassel. Farmers should understand that early season N deficiency may have limited corn’s yield potential and consider this point when making profitable, late season sidedress decisions.
Reports are for crop conditions up to June 6, 2024.
Western Maryland
I have a good friend who says, “I don’t have forty years of experience farming; I have one year’s experience forty times.” This spring has been just like that. We have had more moisture than last year, but then came the hot days, cool weather, and more moisture. Corn is planted, and the first cutting of hay is in the barn. Soybean planting is winding down, and grain harvest will be here before you know it, starting with barley. With the moisture we will see how much disease took its toll. Fungicide applications weren’t always as timely as we would hope because of the frequent showers. Until next month when harvest is underway it is then the story will be told.—Jeff Semler, Washington Co.
Central Maryland
Planting is almost complete. Slugs have been an issue; some soybean fields will need replanting. It was getting a bit dry, which did provide a good hay-making window. However, a thunderstorm is rolling in as I write this, giving us some needed moisture. Small grains are looking good. Summer annual weeds like pigweed, crabgrass, and foxtail are starting to take off with this warmer weather.—Kelly Nichols, Montgomery Co.
Northern Maryland
Spring has been a little challenging in our area. A dry spell in mid-late April made herbicide efficacy less than ideal, followed by several weeks of a lot of rain, which activated herbicides but prevented the timely termination of other cover crops. Early planted corn and beans are up and out of the ground, with earliest planted corn around V6 and getting it’s second shot of nitrogen. Rainy weather in late April early May delayed planting the remainder of the crop by about two weeks. These later planted fields are much further behind than usual but are looking good. There has been some slug damage present, it gets worse the further west you go in the region. Barley nearing harvest and wheat is starting to turn. There are symptoms of head scab but it remains to be seen how severe DON levels are in the grain. The wet weather has made it very difficult to make timely dry hay.—Andy Kness, Harford Co.
Upper and Mid Shore
Corn acreage is looking good, with a nice color and uniform growth. Depending on when it was planted, corn is in the V2 to V5 stages right now. Most of our full-season soybeans are already in the ground. As usual, rain across the region has been hit or miss, with some areas getting a lot more than others. These downpours might not be ideal, but they’re certainly better than no rain at all. Barley harvest is just around the corner. Summer annual weeds are popping up and are ready to impact yield potential. If your residual herbicide program hasn’t kept them in check, now’s the time for a POST application. And remember, using multiple modes of action in your tank-mix slows down the evolution of herbicide resistance in weeds.—Dwayne Joseph, Kent Co.
Lower Shore
has been planted and currently in emergence stage to around V4 stage. Corn is looking good, and being sprayed to combat early season weeds. Soybean planting is currently underway. In a few instances, early planted soybean (early April) had to be replanted due to slug damage. Wheat is looking good and drying down. Farmers are gearing up to cut wheat, which is earlier than anticipated.—Sarah Hirsh, Somerset Co.
Southern Maryland
As I write this, a very welcome rain is falling outside my window. As we move into the hotter days of June, the old adage that we are only a week away from a drought at any time is holding true. Two weeks ago it was too wet to get into fields and this week we have corn fields starting to show curling leaves and drought stress. In general corn is off to a good start with most sidedress N applications completed. There have been a lot of catch up full season beans planted in the last 2 weeks. Slug feeding has been minimal this year. Barley is drying down with harvest expected any day. Wheat will not be far behind. Ryegrass continues to be a challenge for producers in both burndown situations in corn and beans, as well as small grains. Many fields may need a harvest aid to kill the ryegrass and allow for timely harvest of wheat. Given the wet conditions following flowering, we are encouraging producers to get the wheat crop off as quick as possible to maintain grain quality.—Ben Beale, St. Mary’s Co.
Emily Zobel, Senior Agriculture Agent Associate | ezobel@umd.edu
University of Maryland Extension, Dorchester County
Corn
Continue scouting for cutworms and stink bugs. The threshold for cutworms is 2-5% cut plants up to the V5 stage and with active larvae present. Stinkbugs will move into corn as surrounding small grains are harvested. When scouting for stinkbugs, pay close attention to the thorax of brown color stink bugs as the beneficial spined soldier bug is often mistaken for the invasive brown marmorated stink bug. The spined soldier bug has a prominent spine on each “shoulder.” NCSU’s suggested threshold is 13 stinkbugs per 100 plants for V1-V6, 10 stinkbugs per 100 plants for V14-VT, and 28 stinkbugs per 100 plants for R1-R2. The most critical time to treat if between V14 to VT is just before the primary ear is exposed to avoid banana ear. Stinkbugs will likely be around the primary ear at this point so that should be the target of the application.
Soybean
Early-season defoliator pests that are active right now include bean leaf beetles, green cloverworms, slugs, and grasshoppers. Soybeans can typically withstand a decent amount of defoliation before yield losses occur. If defoliation reaches 30%, and you are finding one grasshopper per sweep or 2-3 bean leaf beetles per plant treatment may be advisable.
Figure 1. Bean leaf beetle with feeding damage on a soybean leaf. Photo by Adam Sisson, Iowa State University, Bugwood.org.
Alfalfa
Begin scouting for potato leafhopper. Ten sets of 10-20 sweeps using a sweep net should be taken in random locations in the field. A detail threshold for alfalfa is based on the plant size and cost of the hay can be found online but a general guideline is 3” or less is 20 leafhoppers per 100 sweeps, 4-6” tall is 50 per 100 sweeps, 7-10” tall is 100 per 100 sweeps, and greater than 11” is 150 per 100 sweeps. If the field is more than 60 percent bud stage or if it has experienced “hopper burn,” the alfalfa should be cut instead of sprayed. Fresh-cut alfalfa should not be sprayed as leafhopper adults tend to move out of the field when it is being cut.
Figure 2. Potato leafhoppers in a sweep net. Photo by Bryan Jensen, University of Wisconsin, Bugwood.org.
Learn about the use of drones in agronomic production systems and what you will need to legally operate. Farmers, ag service providers, or anyone interested in the technology is encouraged to attend.
Dates:
June 25, 2024 | Harford County Ag Center (3525 Conowingo Rd., Street, MD 21154)
August 1, 2024 | Wye Research & Education Center (124 Wye Narrows Dr., Queenstown, MD 21658)
August 2, 2024 | Upper Marlboro Research & Education Center (2005 Largo Rd., Upper Marlboro, MD 20774)
*This is a one-day seminar with multiple dates and locations*
Time: 8:30 a.m. – 1:30 p.m.
Cost: $10.00 ( Please send check or cash to the Harford County Extension Office, 3525 Conowingo Rd., Street, MD 21154). Checks should be payable to the University of Maryland. Morning refreshments and lunch will be provided. Contact Andrew Kness (akness@umd.edu) or Erika Crowl (ecrowl@umd.edu) with any quiestions.
Andrew Kness, Senior Agriculture Agent | akness@umd.edu
University of Maryland Extension, Harford County
Tar spot is on the mind of many farmers as we enter the 2024 growing season and I have had many conversations with farmers and consultants about strategies for managing this disease. Here are some things to consider and keep in mind as we get into the peak of the corn growing season.
Tar spot is a disease of corn caused by the fungus Phyllachora maydis. This disease was first reported in limited amounts in Harford and Cecil County in 2022; in 2023 the disease spread to at least 8 counties in Maryland and by harvest ‘23, we found tar spot at a frequency of over 50% of fields scouted here in Harford County.
The tar spot disease cycle starts with old corn crop residue where the fungal spores lay dormant over winter. As conditions become optimal for its development in late spring/summer, spores are released and blown and/or splashed onto corn plants where the spore will germinate and infect the plant. Approximately 12-15 days after infection, symptoms will develop on the corn leaves and/or husks, which include dark, raised, lesions, which are the reproductive structures called stromata (Fig. 1). Inside the stromata are spores (Fig. 2), which are released and will infect new tissue. Tar spot is a polycyclic disease, meaning it has multiple generations or cycles per year. New infections will occur throughout the growing season for as long as green, living corn tissue is present and environmental conditions are favorable.
Figure 1. Tar spot stromata (raised black specks) on corn leaf.Figure 2. Microscope image of P. maydis ascus containing ascospores, which are blown and splashed to infect new corn tissue. Image: A. Kness, UMD.
Here in Maryland and the Mid-Atlantic, tar spot has not been reported to cause any significant epidemics or yield losses thus far, mostly because it becomes established late in the growing season; but that is not to say that serious epidemics couldn’t happen. In the Midwest, tar spot has been reported to cause upwards of 50 bushel per acre yield loss, and it was ranked the #1 yield-limiting disease for corn in the U.S. in 2021, 2022, and 2023.
Since tar spot was first confirmed in the United States in 2015, we have learned a lot about its epidemiology. Tar spot hails from the cooler mountain areas of Latin America. When tar spot first moved into the U.S., we had initially thought that mild temperatures and moisture were key variables in the development of the disease; however, recent research has found that moisture plays a role, but temperature is far more crucial. Webster et. al. (2023) found that monthly temperature average between 64-73°F were optimal for tar spot development and temperatures exceeding 73°F significantly reduced tar spot progression. What was more interesting is that they found that moisture both promoted and inhibited tar spot disease progression. Moisture early in the disease cycle aids in infection, but prolonged moisture (greater than 90% humidity) actually inhibits disease progression. Tar spot develops when relative humidity is less than 90% for a 2-3 week period, coupled with mild temperatures. This makes sense for many that may have observed tar spot in 2023, which was not a particularly wet year.
With this in mind, we should consider how these weather parameters influence our management of this disease here in Maryland where our summers tend to be hotter and more humid than many areas of the corn belt states.
If you look at the 5-year average monthly temperatures from regional weather stations (Table 1), you can see that the months of July and August for Mid-Atlantic regions are well outside of the 64-73°F window for optimum tar spot development. Compare that with data from Iowa for example, and they consistently run within or very close to the optimal temperature range. While only a few degrees may not seem like much, I believe our hot summers may actually keep tar spot at bay until later in August and September on an average year, which would be consistent with when we have found tar spot in Maryland in 2022 and ‘23. If these trends hold true, the majority of our corn crop is well into later grain fill stages by the time milder temperatures arrive, effectively avoiding tar spot development during the most crucial growth stages. In contrast, 30-day average temperatures are within or near the 64-73°F optimum range during corn’s most vulnerable growth stages in the corn belt.
Table 1. Average Monthly Temperatures (°F), 2019-2023
Westminster, MD
Salisbury, MD
Arlington, VA
Waterloo, IA
May
63.46
64.08
66.13
60.70
June
72.48
72.95
75.53
72.90
July
79.54
77.99
80.96
75.52
August
77.22
76.25
78.77
72.00
September
69.94
69.99
72.60
66.20
Where tar spot could become problematic here are instances where we have an unusually cool June and July which would put the majority of our corn at risk of tar spot infection during it’s most vulnerable time, which is tasseling through early to mid grain full.
Another situation where tar spot could be a problem is for late planted and late maturing hybrids that are in reproductive phases in August and September. Fields that are corn after corn are also in a higher risk situation.
For 2024, I would highly recommend scouting and paying close attention to the weather conditions just prior to tasseling through grain fill in your corn fields. There is an app that can help you determine your tar spot risk, called Tarspotter, and has been reported to be 90% accurate. The app takes into consideration regional weather data and field management to determine a risk percentage. It’s available for download for free on iPhone and Android.
If you decide to treat your corn with a fungicide to manage tar spot, VT/R1 timing is still found to be the most effective and economical. A fungicide application at this time will also effectively manage other common foliar fungal diseases of corn (which we shouldn’t forget about), such as grey leaf spot and northern corn leaf blight. Most fungicides labeled for tar spot are effective, however there is a better response to products that have 2 and 3-way modes of action.
This year we will continue to conduct research on tar spot in Maryland with funds from the Maryland Grain Producers Utilization Board. If you find tar spot this year, please report your findings to me via email (akness@umd.edu) or phone (410-638-3255) or on corn.ipmpipe.org.
Nidhi Rawat, Small Grains Pathologist University of Maryland, College Park
Wheat in Maryland has either already flowered or is finishing-up flowering. The FHB prediction maps for today and up to the next 6 days predict high FHB risk. If your wheat is still in the window for FHB fungicide application (from flowering up to the following 4-7 days) you should consider the application of FHB fungicides: Miravis-Ace, Prosaro, Prosaro-Pro, or Sphaerex. These fungicides are also effective against other fungal foliar diseases such as stripe rust, powdery mildew, and tan-spot etc. Strobilurin-containing fungicides are not recommended for application at this stage.
June 11 and 12 at the Hyatt Regency Chesapeake Bay in Cambridge, MD
The Salinity-Affected Lands in Transition (SALT) Conference will host experts on saltwater intrusion and sea level rise and feature discussions on topics like coastal farming, ghost forest adaptation solutions and mitigation strategies. The goal of this conference is to raise awareness about the invisible floods impacting coastlines and agricultural lands like on the Eastern Shore, and to bring stakeholders together to discuss the science gaps and policies necessary to help build coastal resiliency.
This conference marks the culmination of a multi-institutional research project on the Delmarva Peninsula being performed by colleagues at the University of Maryland College of Agriculture and Natural Resources, as well as the University of Delaware and George Washington University. The Hughes Center is assisting with outreach and stakeholder engagement on this project.
Attached is a press announcement as well as a flyer for the conference. We urge you to consider attending by registering hereby June 3.
Nidhi Rawat, Small Grains Pathologist University of Maryland, College Park
Wheat is mostly ending flowering across Maryland now, except for some late-planted fields. The FHB prediction map shows enhanced FHB risk. If your wheat flowered within the past 4-7 days, you are still in the window for FHB fungicide application. This season, we are also observing several foliar diseases such as stripe rust, powdery mildew, BYDV, and tan-spot in our variety trial plots. Some farmers are also reporting these issues from their fields. If you are considering the application of fungicides at this stage, use FHB fungicides: Miravis-Ace, Prosaro, Prosaro-Pro, or Sphaerex. These will control other fungal diseases, in addition to FHB, but not BYDV. For BYDV none of the fungicides can provide control, as it is a viral disease, and genetic resistance is the only real solution for it. Strobilurin-containing fungicides are not recommended for application at this stage.
Reports are for crop conditions up to May 3, 2024.
Western Maryland
April has brought us many showers. The triticale is all in the silos for the most part, and corn planting has begun. The wheat and the barley are looking good. Producers have a keen eye out for FHB, and thus, fungicide is on the docket. Pastures are looking good and first cutting alfalfa is not far off. Warmer temperatures are on the horizon.—Jeff Semler, Washington Co.
Central Maryland
The wet, cool spring has turned into a hot, dry spring this week. Currently, the highest chance of rain (about 60%) is for this weekend. Planting is in full swing, and the first cutting of orchardgrass will start in a couple weeks. Wheat and barley are heading; if the drier weather keeps up, it will lower the risk for Fusarium.—Kelly Nichols, Montgomery Co.
Northern Maryland
Rain has been hard to come by with only about 1” of accumulated rain in the last 4 weeks. Corn and soybean planting has been in rolling for 2.5 weeks now, with a very large majority of it within the last week to 10 days or so. Small grains generally look very good, pastures and hay fields have also enjoyed the cooler than normal March and April. Wheat is anywhere from boot to head emergence. After a soggy start to April, we could use some rain.—Andy Kness, Harford Co.
Upper and Mid Shore
The rains from early in the month are now just a memory, with clear skies and no significant rainfall since. Dust clouds swirling on the horizon are a clear sign that #Plant2024 is underway. Farmers are terminating their cover crops and tilling the soil, readying it for planting. This year, we’re running a week or two ahead of last year’s schedule, raising hopes for another bumper crop. Small grains are currently heading, with some currently flowering.—Dwayne Joseph, Kent Co.
Lower Shore
After a rainy stretch, we’ve gotten some dry weather this past week. About half or more of cover crop acreage has been terminated. Some ground is being tilled, while the majority will be planted no-till. Corn is currently being planted. Wheat is looking very good. If wheat varieties are susceptible to Fusarium Head Blight and if the wheat is flowering, fungicides should be considered. The first cutting of hay has started.—Sarah Hirsh, Somerset Co.
Southern Maryland
Field conditions are a mixed bag. Areas to the north have turned dry in the last week. Areas to the south received more rain delaying field operations. In drier areas, soil has become hard and compacted, aggravated by wet conditions over the winter. This is a year where big differences in soil conditions can be observed between no-till and tilled fields. Planters have been rolling for the last two weeks with conditions mostly ideal for planting. Corn emergence looks good so far. Slugs were a concern early, but drier weather has helped with that issue. We have many acres of early planted soybeans again this year. Burndown programs have been challenged this year with many escapes of annual ryegrass. Wheat is headed and beginning to flower now. We are observing some yellowing of the flag leaf and leaf below the flag leaf across many fields that showed up in the last 10 days. We are working to determine the exact cause, but believe it related to environmental conditions with perhaps some virus issues like BYDV as well. A lot of good dry hay has been made in the last two weeks. On the fruit and vegetable front, plasticulture strawberries look very good and are ripening now. All of our main season vegetable crops are preparing to go in the ground this week. High tunnel crops are coming off now.—Ben Beale, St. Mary’s Co.
Reports are for crop conditions up to July 5, 2024.
