Maria Cramer, Graduate Student and Kelly Hamby, Entomology Specialist Department of Entomology, University of Maryland, College Park
Recently planted field crops may be at risk from slug damage due to the heavy rains and cooler temperatures we have experienced in the mid-Atlantic from the end of April into the beginning of May. Therefore, the UMD fact sheet “Managing Slugs in Field Crops Using IPM Principles” may be of interest. This fact sheet summarizes the most up-to-date research on managing slugs in our area. Highlights include:
Identify the pest and monitor. Make sure the issue is slugs. If it is cool and overcast you may find slugs (Figure 1A+B) or slug eggs (Figure 2) in crop residue. Otherwise, as they are nocturnal, you may only find their damage on plants (Figure 3A+B). Corn is generally tolerant to defoliation, while soybeans are at risk if the growing point of the plant is damaged.
Prevent. If you have not planted yet and if possible, use row cleaners and adjust the planter so that the seed slot fully closes to reduce the risk of damage. In the long term, reducing insecticidal seed treatments may favor slug predatory insects and harvestmen.
Treat. If you use a slug bait, maximize efficacy by applying just prior to slug activity (in the afternoon or evening when weather is still and mild), but not before periods of heavy rain which may make the active ingredient less effective. Remember, the label is the law. Make sure the product you use is registered in your state and for your crop(s). Follow all application restrictions.
Figure 1. A) Gray garden slug and B) Marsh slug.Figure 2. Slug eggs in corn residue.Figure 3. A) Foliar feeding in corn with dried mucus, and B) feeding on soybean cotyledons showing characteristic pitting.
Kurt Vollmer, Extension Weed Management Specialist | kvollmer@umd.edu University of Maryland Extension
In last month’s issue of Agronomy News, I discussed considerations for glyphosate-based burndown programs. This month I wanted to share some of my results using similar programs to manage a rye (Fig. 1) and hairy vetch (Fig. 2) cover crop. Treatments were applied on April 11, and consisted of glyphosate, glufosinate, paraquat, glyphosate + 2,4-D, glyphosate + dicamba, glyphosate + glufosinate, and glyphosate + paraquat. Currently, this is what I am seeing:
Glyphosate tank mixed with 2,4-D, dicamba, and glufosinate are doing an excellent job controlling hairy vetch, and glufosinate alone is providing similar control (Fig 3.);
Vetch control appears to be declining with individual treatments of glyphosate and paraquat, as well as the mixture of the two (Fig. 4);
Glyphosate + 2,4-D is doing an excellent job controlling cereal rye (Fig. 3b), but control with glyphosate alone has improved (Figs. 4a, 4b).
Figure 1. Hairy vetch control 2 and 3 weeks after application (WAA).Figure 2. Cereal rye control 2 and 3 weeks after application (WAA). *Glyphosate containing treatments consisted of 20.5 fl. oz./A Roundup PowerMax3®; glufosinate containing treatments consisted of 43 fl. oz./a Liberty 280®, paraquat containing treatments consisted of 3 pt/A Gramoxone SL 2.0®, 2,4-D containing treatments consisted of 2 pt./A Enlist One®, and dicamba containing treatments consisted of 12.8 fl. oz./A Engenia® *Ammonium sulfate (8.5 lb./A) was included in all treatments except the glyphosate + dicamba treatment, nonionic surfactant (0.25% v/v) was included with 2,4-D and dicamba treatments, crop oil (1% v/v) was included with paraquat treatments. *Treatments were applied using Turbo Teejet 11002 nozzles at spray volume of 15 gal/A.
As previously discussed, the same herbicide program may not have the same desired effect on all species. Here are some things to remember.
There are certain species where control with glyphosate can be difficult, even if those species are not classified as being glyphosate-resistant. Additional trials from the Mid-Atlantic have also indicated lower vetch control with glyphosate alone (Figs. 4a, 4b) compared to glyphosate tank mixtures (Figs. 3b, 3c, 3d).
Group 4 herbicides such as 2,4-D and dicamba, will not control grasses. In addition, including dicamba in a tank mix with glyphosate has been shown to reduce glyphosate’s ability to control grasses (Fig. 3c).
Contact herbicides such as glufosinate and paraquat require good spray coverage for optimal control. If plants are too large, if spray volume is too low, or if nozzles do not provide adequate spray coverage, then plants can regrow (Figs. 4c, 4d).
Figure 3. Efficacy of preplant herbicides for managing a rye/vetch cover crop 2 weeks after applicationFigure 4. Differences in herbicide efficacy for managing a rye/vetch cover crop 2 and 3 weeks after application.
Andrew Kness, Senior Agriculture Agent | akness@umd.edu University of Maryland Extension, Harford County
Figure 1. Signs and symptoms of tar spot on corn. Black raised areas are tar spot and long rectangular grey lesions are from grey leaf spot.
Tar spot is a foliar disease of corn caused by the fungus Phyllachora maydis and we confirmed it for the first time in Maryland from a grower field in Harford County in 2022; however, it is likely that it has been present in fields at low levels earlier than the 2022 growing season. Weather conditions across northern Maryland and Southern PA in August and September were favorable for tar spot development and pockets of disease outbreaks were reported, leading to much discussion about the disease amongst farmers and ag service providers over the 2022-2023 winter months about what to do to manage this disease in the future.
The pathogen that causes tar spot is favored by cool, wet weather. Tar spot spores overwinter in old corn crop residue and it seems to survive our winters just fine, as demonstrated by winter survival in Pennsylvania, as well as many northern corn belt states.
Temperatures between 60-70°F, coupled with 7+ hours of leaf wetness from dew, humidity, rain, or irrigation, trigger sporulation and subsequent spore germination on susceptible corn plants. Roughly 14-21 days later, signs and symptoms of tar spot will develop on corn plants in the form of small, raised black spots that have the appearance of tar or splattered black paint (Figure 1). These spots are the reproductive structures which provide secondary inoculum that repeatedly infect more tissue for as long as temperature and moisture conditions remain conducive.
In the Midwest where tar spot has been present since 2015, yield losses have been reported upwards of 60 bushels in bad years. It is also important to note that tar spot can make corn plants senesce and dry down much faster than normal, going from green to brown in 10-14 days under optimum conditions. This can make silage harvest tricky, which is why scouting is so important.
We do not know how prevalent and severe this disease will become in Maryland, so I encourage farmers to diligently scout corn fields to get ahead of it and also to determine where the disease is distributed. Scouting will also help you determine if a fungicide application is warranted. Fortunately, most fungicides that are labeled for corn do a fairly good job of protecting against tar spot, but there is data that suggests that the two and three way mode of action (MOA) products work better than single MOA products.
Fungicides should be applied as close to disease onset as possible; for tar spot this can be tricky because it can infect corn at any growth stage and it can still have significant yield impact as late into the season as R4. University research in the corn belt has found that the best chance for an economic return on investment is a single application around VT-R1; however, there are some instances where a second application was necessary but these were only when weather conditions for tar spot remained favorable during these later reproductive growth stages.
A few things to consider for tar spot management as we go into the 2023 growing season are as follows:
Avoid highly susceptible hybrids, especially in corn-on-corn fields or if you have a field with history of tar spot. There is no complete resistance to tar spot in commercial corn hybrids, but we do know there is some variability in susceptibility. Work with your seed dealers to try to identify your best hybrids and plant them in these fields where you think tar spot may be a problem.
Tillage and residue management appears to play a minor role in the management of this disease. Tillage may slightly reduce primary inoculum, but we need to keep in mind that tar spot spores can blow in from neighboring fields; so, I would not roll out the heavy tillage and blow up your no-till system just to try managing tar spot because it will only have a marginal effect.
Corn-on-corn has a higher risk for developing tar spot, especially if the previous corn crop was infected. Rotate with other crops to break up this cycle. P. maydis only infects corn (including dent, sweet, and popcorn); all other crops are not hosts.
Hybrid maturity also plays a role in disease severity. Research from the Midwest has shown that longer maturing hybrids suffer greater yield loss than shorter maturing hybrids. This is because the longer you push the grain fill period into the cooler late summer/fall months, the more likely tar spot will infect during earlier grain fill growth stages.
Scout fields this year starting a little before tasseling through to maturity. As mentioned above, this will help you determine if a fungicide is likely to pay off or not.
We will be conducting some field trials this year looking at tar spot management in Maryland with funds from the Maryland Grain Producer’s Utilization Board. Part of this project will also include a survey of corn across the state to determine the distribution of tar spot. If you think you find tar spot in a field this year, I would be interested in knowing about it. You can call or email me (410-638-3255, akness@umd.edu), or report a sighting at corn.ipmpipe.org.
Kurt Vollmer, Extension Weed Management Specialist | kvollmer@umd.edu University of Maryland Extension
It’s that time of year when growers are considering which herbicides to include in their burndown programs. Utilizing effective herbicides will help to ensure less weed competition at planting. However, growers should consider not only what herbicides they plan to use in their burndown programs, but also the weed species present in the field.
The most common preplant treatment for both corn and soybean is either a combination of 2,4-D + glyphosate or dicamba + glyphosate. These mixtures can provide good to excellent control of winter annual weeds such as common chickweed and common groundsel, as well as good control of emerging summer annual species such as common lambsquarters and foxtail species. These herbicides can also control henbit, purple deadnettle, and mustard species if sprayed before flowering and seed set. However, control may be reduced with winter annual weeds such as Carolina geranium and field pansy, as well as perennial species such as curly dock. If Carolina geranium and field pansy are present, consider adding atrazine or metribuzin to the tank mix. If curly dock is a problem consider using Harmony + 2,4-D.
The use of these herbicides will also influence planting date if using non-tolerant varieties, such as Enlist® (2,4-D) and XtendFlex® (dicamba). Generic forms of 2,4-D or dicamba should be applied 7 to 14 days before or 3 to 5 days after planting corn. The planting interval for soybean will depend on the amount of product applied. For most generic 2,4-D esters (LVE), wait at least 7 days if using 1 pt/A and at least 30 days if using 2 pt/A. However, some LVE formulations allow a 15 day application interval, be sure to consult the product label for specific instructions. The planting interval for dicamba formulations is at least 14 days if 0.5 pt/A is applied and at least 28 days if 1 pt/A is applied.
Glyphosate resistant weeds such as horseweed (marestail) and common ragweed may also be present at the time of application. Be advised that when using combinations of glyphosate and 2,4-D or dicamba, the 2,4-D or dicamba component is being relied upon to control these weeds. Therefore, these species should be sprayed when they are small (< 6 in.). Local data has shown applications of 2,4-D or dicamba made 30 days before planting to be more effective on horseweed than applications made 14 days before planting. Sharpen® is another option for controlling horseweed that is less than 6 inches tall.
Finally, it is important to note the importance temperature will play in the efficacy of these herbicides. When the temperature is lower than 60˚F, weed growth slows, resulting in reduced uptake and translocation of systemic herbicides like 2,4-D, dicamba, and glyphosate. If the temperature is below 40˚F, it is best to avoid applying these herbicides until conditions are more suitable. Fortunately, it looks like warmer days are ahead!
The Maryland Grain Producers encourages you to sign-up for one of the three new on-farm research trials for the 2023 growing season! Maryland grain check-off dollars are funding technical assistance through the University of Maryland and compensation to you, for this year’s on-farm research. Conducting this applied research on farms will lead to meaningful agronomic production data across the state at the field scale.
The three different trials are listed below. Full protocols can be found online at https://go.umd.edu/3n39mzm.
Nitrogen Rate – the study is evaluating corn yield response to a range of nitrogen application rates.
Biological Product Evaluation – the study is going to determine the impact of biological fertilizer enhancement products on corn yield.
Potassium Rate – the study will evaluate corn yield response to potassium fertilizer to determine the agronomic critical level and adjust land-grant fertilizer recommendations.
The University of Maryland has been funded by check-off dollars to benefit the future of Maryland grain production, by doing on-farm research. Dr. Nicole Fiorellino and Gene Hahn, the On-Farms Trials Coordinator, will be working directly with you to provide hands-on assistance throughout the entirety of the trial. Compensation is available to participating growers who complete the protocols on their farms.
Findings will be aggregated with no identifying information or location and shared for other farmers to see and learn more. Contact Dr. Fiorellino directly at 443-446-4275 or at nfiorello@umd.edu to enroll today!
This month’s 2022/23 U.S. corn outlook is for lower exports and larger ending stocks. Exports are reduced 75 million bushels reflecting the poor pace of sales and shipments to date despite relatively competitive U.S. prices. With no other use changes, ending stocks are up 75 million bushels from last month. The season-average corn price received by producers is lowered 10 cents to $6.60 per bushel based on reported prices to date. Ending stocks-to-use ratio increased from 9.1% in February to 9.7% in March.
Soybeans
U.S. soybean supply and use changes for 2022/23 include higher exports, lower crush, and reduced ending stocks compared with last month’s report. Soybean exports are raised 25 million bushels to 2.02 billion based on higher-than-expected shipments through February. Soybean crush is reduced on a small reduction in domestic soybean meal disappearance combined with a higher extraction rate. With higher exports more than offsetting lower crush, ending stocks are reduced 15 million bushels to 210 million. If realized, ending stocks would be the lowest in seven years. With relatively strong domestic demand for soybean oil limiting export competitiveness, U.S. soybean oil exports are reduced 200 million pounds to a historically low 500 million. Higher domestic use and reduced production are offsetting, leaving soybean oil stocks unchanged this month. Ending stocks-to-use ratio decreased from 5.2% to 4.8%, the lowest since the 2012/13 marketing year.
Wheat
The 2022/23 U.S. wheat supply and demand outlook is unchanged from last month. The projected season-average farm price remains $9.00 per bushel.
Shannon Dill, Principal Agriculture Agent University of Maryland Extension, Talbot County
The University of Maryland Extension has updated the grain marketing website (www.go.umd.edu/grainmarketing) with new input data and spray programs for the 2023 field crop budgets. Also posted is the recent 2023 Maryland and Delaware Custom Rate Survey.
Crop Budgets
Cost of production is essential when making decisions about your farm enterprise and grain marketing. Enterprise budgets provide valuable information regarding individual enterprises on the farm. An enterprise budget uses farm revenue, variable cost, fixed cost, and net income to provide a clear picture of the financial health of each farm enterprise. This tool enables farm managers to make decisions regarding enterprises and plan for the coming production year.
The 2023 Maryland enterprise budgets were developed using average yields and estimated input costs based on producer and farm supplier data. The figures presented are averages and vary significantly from one farm and region to the other. It is, therefore, crucial to input actual farm data when completing enterprise budgets for your farm.
Cost Per Acre 2023
Corn – No Till
Corn – Conventional
Soybeans
Wheat
Wheat/Beans
2022
$689.00
$749.00
$402.00
$490.00
$749.00
2023
$735.50
$799.57
$422.86
$537.64
$800.23
Difference
$46.50
$50.57
$20.86
$47.64
$51.23
Percent Change
7%
7%
5%
10%
7%
How to Use University Enterprise Budgets:
The enterprise budgets can be used as a baseline for your operation. Make changes to these budgets to include your production techniques, inputs, and overall management.
Use this document as a start or reference to creating your crop budgets. The budgets are available electronically in PDF or Excel online at www.extension.umd.edu/grainmarketing. Contact information is on the website if you have problems downloading any of these budgets.
2023 Custom Rate Survey Now Available for Maryland and Delaware
Financial and economic considerations such as limited capital, untimely cash flow, low labor, small acreage, or other reasons require farmers to hire custom services for field operations.
Custom work charges are determined by demand and supply and are negotiated between farmers and custom operators. The purpose of the publication is to provide information on custom work charges in Maryland and Delaware.
Custom Work Charges
A mail survey was conducted in the fall of 2022 to determine custom works charges in Maryland and Delaware. Rates were collected from 67 custom operators and farmers and summarized for the state. Participants indicated the rates they charge for various field operations. The charges reported in this publication may serve as a guide in determining an acceptable rate for a particular job where little other information is available. The charges can also be compared with costs and returns and may be used as a basis for working out more equitable charges for both the custom operator and the customer. These are available online at www.go.umd.edu/grainmarketing or contact your local Extension Office.
Operation
AVERAGE ’23
AVERAGE ’21
Percent Change
Field Preparation
$20.21
$19.07
6%
Planting
$21.87
$18.31
19%
Field Applications
$14.09
$9.84
43%
Forage Production
$15.17
$12.32
23%
Harvesting
$73.07
$71.30
2%
Labor
$42.19
$40.38
4%
Equipment Expenses
$85.50
$71.23
20%
Average Total Change
$38.87
$34.64
12%
*The accuracy of this survey depends on the number of realistic responses. If you would like to be added to the custom applicator list for future surveys, send your name and email/mailing address to sdill@umd.edu c/o MD Custom Rates.
The 2023-2024 version of the Penn State Agronomy Guide is available at https://extension.psu.edu/agronomy-guide. This is available as a digital download for $15, printed copy for $35, or a print and digital bundle for $45. They are offering a 25% discount through March 25. Enter the code CROPS-8GS in the “apply a discount code” section at checkout.
Queenstown, Maryland (January 26, 2023) – Cost-share is available to farmers interested in adding an additional split to their nitrogen application on their 2023 corn crop. The Mid-Atlantic 4R Nutrient Stewardship Association and their agribusiness partners will work directly with producers in the Chesapeake Bay Watershed for the third and final year of this grant opportunity. Farmers who apply an additional split of nitrogen, and leave a control strip with the same total poundage will be eligible for a $15 an acre incentive payment.
Farmers are eligible to enroll 40 acres or 400 acres, as long as a control strip is available in each field. The 4R Alliance requires past crop and yield data as well as 2023 corn yield checks to analyze and compare results. Data collected over the three-year grant will be compiled for a published case study.
In 2021, five Maryland farms participated and had an average yield increase of 19.2 bushels per acre where they use an additional split to their nitrogen applications versus all of it upfront. Of the 11 participating farmers in Pennsylvania, farmers saw an average yield increase of 17.6 bushels per acre and a 12 percent increase in nitrogen use efficiency. Check out more results here.
To enroll today and to learn more please contact our team! Eric Rosenbaum for Pennsylvania at 484-788-7263 or by emailing ericrosenbaum@rosetreeconsulting.com. For Delaware and Maryland contact Jenell Eck McHenry at 443-262-6969 or by emailing jenell.mdag@gmail.com. Sign-up is encouraged to be submitted by April 1st.
Funding is provided by the National Fish and Wildlife Foundation Chesapeake Bay Stewardship Fund. The Mid-Atlantic 4R Nutrient Stewardship Alliance was awarded a three-year grant for education, training, and cost-share to increase the implementation of 4R Nutrient Stewardship practices. Learn more about our work online at 4rmidatlantic.com.
Nicole Fiorellino, Extension Agronomist University of Maryland, College Park
Results of the 2022 University of Maryland corn hybrid trials are available to view by clicking the link below, or you may visit: https://psla.umd.edu/extension/md-crops. Questions may be directed to Nicole Fiorellino (nfiorell@umd.edu).
