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Fall Pasture Management Tips

Three Angus beef calves in fall pasture sceneWhile summer may be over and the main grazing season concluded, the fall is one of the best times of the year to evaluate the condition of your pasture and complete pasture management tasks that will pay dividends the next grazing season.  Spend some time now before it gets cold preparing your pastures for spring growth.

  1. Soil Test After a summer of grazing, fall is a great time to take soil samples to check and see where you stand on soil pH, nitrogen, phosphorus and potassium.  This is important information to have when making management decisions such as how much fertilizer or lime to apply and if your pasture needs to be renovated. It also allows to apply what is needed to avoid over application which can have negative environmental impacts with runoff and leaching and also result in unnecessary spending.  Testing should be done routinely every 2-3 years or prior to undertaking a partial or full pasture renovation. The University of Delaware offers soil testing as well as several private labs including Agrolab in Harrington.

 

  1. Assess- Take a walk through your pasture. Observe and inventory what desirable pasture species are present, the ratio of grass to legumes, the types of weeds present, the stage of maturity of desirable species and weeds, how much bare soil there is and possibly use a compaction meter to see what the soil compaction levels look like from hoof pressure after a wet growing season.

 

  1. Weed Control- The fall is a great time to do some weed control. Perennial weeds such as horse nettle, dogbane and thistle respond well to fall herbicide applications (as long as it hasn’t been too dry) because they are translocating energy to store in their roots in preparation for overwintering. Herbicides should be applied according to label instructions and prior to the first frost. The Mid-Atlantic Weed Management Guide is an excellent regional resource and has a chapter devoted to forage weed management: http://extension.udel.edu/ag/weed-science/weed-management-guides/

 

  1. Lime- Based on your soil test results, apply lime in quantities to increase soil pH appropriately. Over time without the application of lime, soils generally become more acidic. The addition of certain fertilizers such as ammonium sulfate can also make soil more acidic.  Acidic soils make nutrients less available for pasture species to uptake. Most pasture species prefer a soil pH between 6.0-6.5.  Raising soil pH not only makes nutrients more available to pasture grasses and legumes for uptake but can also make soil bacteria more active which helps to release nutrients.  Based on your soil test results you will apply either high calcium lime or high magnesium (high mag) lime depending on your needs. Additional recommendations for liming pastures can be found here: http://extension.udel.edu/factsheets/forage-and-hay-crops/

 

  1. FertilizeBased on your soil test results, and provided there is adequate soil moisture, apply nitrogen (N), phosphorus (P) and potassium (K) as needed. Soil test results allow you to apply the correct amounts of fertilizer needed which saves money and avoids over application. Fall is widely recognized as one of the best times to apply fertilizer.  Fall applications of fertilizer help pasture stands to be hardier, overwinter better and be more productive in the spring.  Phosphorus helps with root growth and development which in turn helps with pasture persistence and longevity of a stand.  Potassium functions much like anti-freeze in a plant and assists it in coping with hot dry or extremely cold weather.  Nitrogen provides for leaf growth and development and fall applications of nitrogen help boost pasture production the following spring.  Fall applications should be completed by early November. Remember that Delaware nutrient management laws do not permit commercial fertilizers to be applied between December 7 and February 15. Additional recommendations for fertilizing pastures can be found here: http://extension.udel.edu/factsheets/forage-and-hay-crops/

 

  1. Mow/Drag– Mowing pastures promotes more even growth after a summer of grazing and can assist in weed control by clipping weed seed heads before they are viable. Pastures should be mowed no shorter than 3-4 inches to allow enough residual plant material for pasture species to store energy reserves for the winter. Dragging a pasture spreads manure more evenly then a cow or horse will. It also offers some benefit for internal parasite control by exposing parasites and their eggs to sunlight and desiccation or drying.

 

  1. Rotationally Graze or Strip Graze- Develop a grazing plan based on your visual evaluation of your pastures to rest and rotate your pastures. Divide your pastures into smaller areas to reduce selectivity and force animals to graze more evenly if you find that forage is becoming too mature and being wasted in some areas of your field and overgrazed in others. Pastures should never be grazed less than 3-4 inches as it causes stress to the plant because they begin to use their root reserves instead of using their leaf material to produce more energy for growth.  If a pasture is continuously overgrazed eventually the desirable pasture species utilize all of their root reserves causing them to die and leave bare spots in the pasture.  Rotational grazing gives pastures a must needed rest in between episodes of grazing.  The length of time regrowth between grazing episodes is dependent on environmental growth conditions.  Strip grazing is a type of rotational grazing and is a great technique for rationing pasture during times of less growth such as winter months. Animals are offered a portion of a field to graze and then are moved on a regular basis once that area is consumed. This is generally high intensity grazing for shorter periods of time.

 

  1. Overseed/Reseed- Fall is actually the best time of the year to reseed a pasture. Seed germinates faster as soil temperatures are warmer than in the spring. Pasture seedlings get several months of a head start on spring weed growth which makes them able to compete better in the stand.  If the existing stand simply needs thickening, then overseeding is a good option.  If soil pH and fertility need dramatic adjustments, soil compaction is severe, weed pressure is heavy and desirable pasture species are thin then a full renovation with conventional tillage is probably in order.  A common mistake is grazing newly renovated pastures too soon. Plants need time for strong root development so they aren’t pulled out by grazing animals or damaged by hooves.  Full renovations require a good year of careful mowing, etc. prior to grazing animals being turned out. If you do not have the room to wait a full year, but still need a full renovation, considering breaking your pasture into sections, seeding one section per year. This way, the new section will be ready for animals as you prepare to renovate the next section the following year. This also helps with expenses, since full renovations can be costly.

 

  1. Stockpile-Tall fescue grass pastures offer the ability to stockpile or grow forage and store it in the field to be grazed in late fall or winter. Tall fescue is uniquely suited to this practice as it actually maintains nutritional content and increases in palatability to the horse after the first frost. In order to stockpile tall fescue in the field for later grazing, an early fall application of nitrogen to stimulate leaf growth is necessary. Wait to graze until late fall or winter and consider utilizing strip grazing to maximize the utilization of stockpiled tall fescue.

 

  1. Choose the Right Forage Species– This is one of the most costly inputs for pasture, yet is also the most important choice you can make for your pasture. Unfortunately, we do not share the same climate as Pennsylvania, Kentucky, or Western Virginia, which provide excellent conditions for perennial, cool season grasses. Our warm, humid environment tends to stress cool season grasses during the summer months, reducing the longevity of some species such as orchardgrass, timothy, and perennial ryegrass. There is an exception-tall fescue, particularly varieties containing the friendly (novel) endophyte, which tend to persist much longer when established correctly. Please note these are different than endophyte-free varieties, which tend to have less vigor. There are many pasture mixes available on the market so be sure to do your homework and be familiar with what is in the mix you are being sold or consider a custom mix of appropriate species for our growing conditions.

 

In conclusion, fall is a great time to evaluate your past grazing season. Think back- did you have times where pasture growth was in excess of what was being utilized by grazing animals?  A time of deficiency?  How can you overcome those times in the future?  What did your pasture look like by the end of the summer?  Often times when asked to make recommendations to help producers manage their pastures more effectively, we discover that pastures are greatly overstocked and continuously grazed.  Even when you follow good management practices, pastures that are overstocked will result in overgrazed, damaged stands that do not persist.  Weeds are opportunists and bare soil allows them to germinate from existing soil reserves or propagate if they are not controlled.  If you do not already have one, consider establishing a sacrifice lot or a place to put animals and feed hay when pastures cannot be grazed for a variety of reasons (too wet, too dry/droughty, no growth, when a pasture has been recently seeded or fertilized, or it is too cold and limiting growth rates).  This practice will help extend the useful lifetime of your pastures.  Hoof pressure on wet pastures in the winter damage the desirable plants and result in soil compaction.  Pastures that are grazed year round are less productive and need to be reseeded more often.

Susan Garey, Extension Agent Animal Science and Phillip Sylvester, Kent County Agriculture Agent

University of Delaware

 

Plan for Winter Dairy Udder Health Now

Sudden shifts in the weather are a stark reminder that dairy producers need to plan ahead to maintain udder health during the winter, says J.W. Schroeder, North Dakota State University Extension Service dairy specialist.

“Winter teat-end lesions are easily triggered when the temperature drops 20 degrees,” he adds. “With inevitable cold winter weather on its way, the advent of teat-end lesions is likely to predispose cows to mastitis.”

Wind chills and temperature changes are the major factors leading to winter teat challenges. Schroeder says the dairy manager’s objectives should be to:

  • Control exposure to weather factors as much as possible.
  • Minimize other teat stressors that exacerbate the problem if cracking or freezing occurs.
  • Keep the teat disinfected, healthy and soft as much as possible through proper milking procedures.
  • Minimize secondary bacterial infections through proper milking practices and environmental sanitation.

“We can’t control the weather, but we can control factors that will ensure cow comfort and the cows’ udder health in the coming weeks,” he says.

Here are ways he suggests producers accomplish those objectives:

  • Control cold temperature exposure by providing windbreaks if animals have to go outside, feeding and housing cows indoors during cold weather when possible, avoiding drafts in buildings by keeping ventilation and openings controlled properly, and avoiding putting animals directly into extreme wind chills post-milking.
  • Control stall/bedding environment by having comfortable, dry areas for animals, providing dry bedding, and maintaining and changing bedding at appropriate intervals. Recent research in Minnesota showed that bedding maintenance is critical to reducing bacterial exposure.
  • Maintain milking equipment by checking vacuum and milk line hoses, pulsators, inflations and vacuum level; keeping pulsators clean; and changing inflations on schedule.
  • Ensure pre-milking sanitation by using procedures that maximize teat disinfection and skin conditioning while minimizing irritation or trauma. Also pre-dip with a good germicidal dip with skin conditioner, blot teats dry instead of rubbing to minimize irritation on problem teats, and use milking hygiene practices like those used to control contagious mastitis (clean hands, gloves and individual towels). Cloth towels are best because they dry teats more thoroughly with less abrasion than other types of towels.
  • Review people/milking machine/time interactions because using proper techniques is imperative to maximize unit performance (maximum flow/unit time) and minimize teat stress (extended milking due to low flow rates or gross overmilking).

“Remember that teat-end changes can occur rapidly in winter with dehydration and cracking, and at other times with acute machine problems,” Schroeder says.

“Minimizing the weather effects through proper facilities and environments is job one. Some practices may need to be altered or adapted during cold weather (dipping, blotting, etc.), and the advantages and disadvantages should be carefully examined when evaluating using new technologies or products such as teat dips.”

To date, researchers have found no protocol that stops cracked teats completely during the winter.

Acute Bloat Syndrome Dairy Calves

Bloat is a common disorder seen in ruminants, such as cattle. However, bloat observed in young calves is very different from bloat seen in cows. According to Smith (2010), bloat in cows is a result of free gas building up in the rumen (the first component of the bovine’s stomach) and causes distention, or enlargement, of the rumen. This distention of the rumen can impair breathing and result in suffocation of the animal. In contrast, bloat in young calves results from gas build-up in the abomasum, the last of the four compartments of the bovine’s stomach (Smith, 2010). The abomasal bloat observed in young dairy calves is often referred to as Acute Bloat Syndrome (ABS). In a survey conducted by Shoemaker et al. (2007), 276 veterinarians across the country reported ABS to occur on a median of four farms per practitioner. ABS is becoming a widely occurring syndrome, and it is important that dairy farmers are aware of this disorder and remain updated on current research. In order to better understand ABS, it is necessary to know which cattle can be affected, the symptoms associated with the syndrome, the potential causes, the treatments, and the preventative measures for ABS.

Acute bloat syndrome occurs in calves. In most cases, calves are usually 4 to 21 days of age (Shoemaker et al., 2007). According to Marshall (2009), ABS occurs sporadically in dairy calves. Some farms will have multiple cases of ABS at one time. Not only is it a good idea to know when calves are susceptible to ABS, but it is also important to recognize the symptoms.

Understanding the symptoms of ABS is critical because calves that develop the syndrome often die within 6 to 48 hours. According to Van Metre and Callan (2006), the case fatality rate is a very steep 75 to 100%. Although the likelihood of saving the calf is low, it is only possible if symptoms are recognized early. Symptoms of ABS include abdominal distension, depression, colic signs, grinding of teeth and salivation, anorexia, fluid slosh in the abdomen, and dehydration. Less common symptoms include diarrhea and high temperature (Shoemaker et al., 2007). According to Panciera et al. (2007), after experimental induction of ABS in calves, the necropsy showed distention, hemorrhage (internal bleeding), inflammation, mucosal necrosis, and mural emphysema (air build-up in the wall of the stomach). The symptoms of ABS usually include a rapid onset and sometimes are not even observed before death occurs. Calves will eventually die from shock or compromised respiration due to the enlarged stomach, according to Van Metre (2017).

The causes of ABS are not well understood; however, experimental induction of ABS in calves led researchers to believe that the cause of ABS is large quantities of highly fermentable carbohydrates and high concentrations of bacteria containing enzymes capable of fermenting the substrate (Panciera et al., 2007). As a result of these two factors, high levels of gases are produced in the abomasum, causing distention. Although researchers are not certain which exact species of bacteria cause ABS, Clostridium perfringens, Sarcina spp, Streptococcal spp, Escherichia. coli, and Salmonella typhimurium have been identified in the abomasum of affected calves. Further research must be done in order to determine the specific role these bacteria play in ABS. Other factors that can contribute to ABS are related to nutrition and include high volumes of milk replacer, cold milk, high osmolality of milk, high protein  and fat contents in milk, high-energy oral electrolyte solutions, and inconsistent feedings. All of these can cause a slower emptying rate of the abomasum. According to Burgstaller et al. (2017), feeding practices that significantly prolong abomasal emptying can increase rates of gastrointestinal diseases in calves.  This is because the bacteria have more time to ferment the feedstuff, thus producing more gas in the abdomen. Familiarity with these causes of ABS will aid in proper decision-making regarding treatment and prevention of the disorder.

Measures for controlling ABS mainly involve dietary management in lieu of medications or procedures (Marshall, 2009). There are no reliable data on whether or not conventional vaccines are helpful. It is thought that vaccines containing inactivated toxins given to pregnant cows will produce antibodies in the colostrum and help protect the calf (Van Metre, 2017). Antibiotics, such as penicillin or oral Beta-lactam which would target Clostridium spp, can be used, but these are not the best treatment option because the species of the ABS-causing bacteria may be different. Other medications that can be given include rumen tonics and anti-inflammatories (Shoemaker et al., 2007). Bloat-relieving procedures, such as placing a stomach tube or puncturing the abomasum to release air, are not necessarily effective treatment options. Since a stomach tube cannot reach the abomasum, the calf’s front end must be elevated in order to allow the gas to pass to the rumen and out the tube (Van Metre, 2017). Puncturing the abomasum must be done while the calf is dorsally recumbent (lying on its back) because there is a high risk of leakage of abomasal contents into the abdomen (Marshall, 2009). For these reasons, procedures and medications are usually not the best treatment options. Dietary management strategies are the preferred ways to prevent ABS. These include feeding the calves multiple, small meals on a consistent basis, mixing the milk replacer correctly according to manufacturer’s instructions in order to lower osmolality, feeding warm milk, and providing adequate amounts of water (Smith, 2010). These dietary management strategies are easy to apply and will increase the passage of feed through the abomasum to the small intestine. Although these are good treatment options and preventative strategies, farms that were rated good to excellent, based on their management practices, still struggled with ABS.

ABS is a spontaneous and puzzling disease that affects many dairy farms. The calves at risk for ABS, associated symptoms of ABS, the potential causes of ABS, and the treatment and prevention of ABS are important factors that must be studied and understood. Unfortunately, there are still many uncertainties and unknowns about this disorder, and further research is needed in order to learn more about the syndrome and the specific species of bacteria that cause it.

Works Cited

Farm Bureau Working on New Milk Price Insurance

By Jim Dickrell January 31, 2017

A new type of dairy revenue insurance, that would offer regional protection against both milk price and production declines, is being worked on by the American Farm Bureau Federation, American Farm Bureau Insurance Services (AFBIS) and academic collaborators including dairy economist Marin Bozic.

The product, known as Dairy-Revenue Protection (Dairy-RP), protects revenue instead of the milk-feed margin.  It is based on the same concepts as crop insurance, and will be submitted for review to USDA’s Risk Management Agency this spring.

To gauge interest, AFBIS is hosting an on-line survey for dairy farmers.  The survey is just 12 questions in length, and takes less than a minute or two to complete. Farmer input will be used to improve the design of the product and for market research. Go here to take the survey.

“Additionally, Farm Bureau believes livestock insurance funding should be enhanced,” says John Newton, AFBF director of market intelligence. “Livestock insurance funding is currently limited to $20 million per fiscal year despite the $130 billion annual value of the livestock sector.”

As currently designed, Dairy-RP insurance contracts would be quarterly, and could be purchased up to 15 months out. Dairy farmers would have three choices to make:

• A milk price blend between Class III and Class IV

• Number of cows to cover

• Coverage level (up to 90%)

To keep things somewhat simple, production per cow would be based on state-level milk production as reported by USDA. Indemnities would increase if production per cow at the state level decreases during the coverage period, or would decrease if state level production per cow increases during the period. “Indemnities would be paid to the dairy farmer if actual revenue falls below the revenue guarantee,” says Newton.

Dairy-RP premiums would be designed to be actuarially sound pre-subsidy. Based on milk prices from 2008 to 2016 and assuming subsidies similar to those in crop insurance, research by Marin Bozic suggests that the average premiums would be 9¢/cwt three months out, 21¢/cwt six months out, 28¢/cwt nine months out and 36¢/cwt 12 months out.

Bozic’s research shows a variety of hedging strategies with Dairy-RP could provide considerable risk management opportunities. One strategy would have resulted in Dairy-RP indemnities in eight of the 32 three-month quarters since the beginning of 2008, including three quarters in 2009, three quarters in 2015, and twice in 2016. In 2009, those indemnities could have approached $5/cwt; in 2016, about $1/cwt. If a farm had Dairy-RP coverage for the entire eight years, its milk revenue would have averaged $16.67/cwt versus $16.27 without it.

“When the market moves milk prices higher, the availability of a tool like Dairy-RP would provide farmers an opportunity to manage risk and lock-in that higher milk revenue,” says Newton.

Summer Forage Tour

Thursday, Sept. 1
3:30-5:00 pm Pre-tour option at Beck-n-Rich Farm

Raphine, VA

Featuring: forage sorghums for silage & baleage
5:00-5:30 pm Registration at Virginia Tech McCormick Farm
5:30-6:15 pm Dinner
6:15-7:30 pm Tour: – summer stockpiling for late-summer grazing,
– crabgrass, lespedeza, & summer annual forages
– building drought resistance with healthy soils

To Beck-n-Rich Farm 4875 Borden Grant Trail Fairfield, VA 24435
Directions from I-81

To VT McCormick Farm
128 McCormick Farm Circle Raphine, VA 24472

-I-81, exit 200
-east on 710 Sterrett Rd (1000 ft)
-left on Rt. 11 (1 mile)
-right on 707 Jonestown Rd (1 mile)
-left on Borden Grant Trail (700 ft)

-I-81 exit 205
-east on Raphine Rd. (½ mile)
-farm on left

QUESTIONS? MATT BOOHER, @ 540-245-5750, MRBOOHER@VT.EDU
Registration is $10 /person; includes dinner and tour.
Payment must be received by Friday, Aug. 26 to account for dinner.

Name Phone
Email

# attending

Make check payable to: “Augusta VCE”
PO Box 590
Verona, VA 24482

Virginia Cooperative Extension programs and employment are open to all, regardless of age, color,
disability, gender, gender identity, gender expression, national origin, political affiliation,
race, religion, sexual orientation, genetic information, veteran status, or any other basis
protected by law. An equal opportunity/affirmative action employer. Issued in furtherance of
Cooperative Extension work, Virginia Polytechnic Institute and State University, Virginia State
University, and the U.S. Department of Agriculture cooperating. Edwin J. Jones, Director, Virginia
Cooperative Extension, Virginia Tech, Blacksburg; M. Ray McKinnie, Interim Administrator, 1890
Extension Program, Virginia State University, Petersburg. If you are a person with a disability and
desire any assistive devices, services or other accommodations to participate in this activity,
please contact Matt Booher at (540-245-5750/TDD*) during business hours of 8 a.m. and 5
p.m. to discuss accommodations 5 days prior to the event.
*TDD number is (800) 828-1120.
This field event is partially funded by a USDA-NRCS Conservation Innovation Grant and the Virginia
Ag Council.

USDA plans to buy 11 million lb. of cheese, extends MPP deadline

Dairy farmers will receive additional assistance from the government following today’s announcement by U.S. Department of Agriculture (USDA) to purchase approximately 11 million pounds of cheese and extend an application deadline.

The cheese purchase will come out of private inventories and will be donated to assist food banks nationwide. The value of the cheese comes to $20 million.

USDA’s purchase would help reduce the highest cheese surplus in 30 years and increase bottom-lines for dairy farmers after a 35% reduction in revenues the last two years.

“We understand that the nation’s dairy producers are experiencing challenges due to market conditions and that food banks continue to see strong demand for assistance,” says Agriculture Secretary Tom Vilsack. “This commodity purchase is part of a robust, comprehensive safety net that will help reduce a cheese surplus that is at a 30-year high while, at the same time, moving a high-protein food to the tables of those most in need. USDA will continue to look for ways within its authorities to tackle food insecurity and provide for added stability in the marketplace.”

In addition to the cheese purchase, USDA will extend the deadline to enroll in the Margin Protection Program (MPP) for Dairy to Dec. 16, 2016. The previous deadline was Sept. 30.

Earlier in the month USDA announced approximately $11.2 million was earmarked for dairy producer financial assistance through the MPP-Dairy program. It is the largest payment since the program began 2014.

A number of groups had asked USDA for assistance in regards to Section 32 of the Agriculture Act of 1935, which allows surplus food to be purchased and donated into nutrition assistance programs. Still, the $20 million purchase does not come close to industry recommendations. National Milk Producers Federation (NMPF) asked for $100-150 million and American Farm Bureau Federation requested at least $50 million.

“This cheese purchase will provide some assistance to America’s dairy farmers through increased demand for their milk,” says Jim Mulhern, President and CEO of NMPF. “We will continue to assess the economic situation facing dairy farmers, and suggest ways to help farmers endure this lengthy period of low prices.”

National Farmers Union (NFU) President Roger Johnson says the help is appreciated but it still won’t fix the business environment dairy farmers work with.

“Current projections indicate that farm revenue from milk sales this year will drop to $31.5 billion – a $20 billion plunge from 2014 revenue highs. Even with modest price rebounds, dairy producers are draining capital reserves, or worse, going out of business,” Johnson says.

Corn Replant

Replant Decisions for Field Corn

 

The Agronomy Team

(Richard Taylor, Joanne Whalen, Mark VanGessel, Nathan Kleczewski, Amy Shober, Phillip Sylvester, Cory Whaley, and Dan Severson, University of Delaware

 

The prolonged period of cold and wet weather this spring plus the usual culprits such as slugs have led to questions about the adequacy of corn stands this year.  In addition, many growers have only recently or have not yet gotten their corn acreage planted.  In this article, the UD Agronomy Team will outline considerations involved in making replant decisions as well as whether to plant another crop, assuming herbicides have not eliminated some choices.

 

The most important consideration when thinking about replanting is timing.  How quickly you can make the final decision to replant and actually replant the crop?  Waiting too long to assess a stand increases the potential yield loss if a decision is made to replant the field.

 

Potential yield loss percentages for delayed corn plantings were developed many years ago: advances in corn genetics and irrigation management have significantly improved hybrid performance.  It is important to note that the loss per day of delay estimates may overestimate the impact of delaying planting.  Yet, these estimates are useful as guidelines for both irrigated and dryland corn production systems.

 

In mid-May for irrigated corn, every day you delay making a replant decision and actually replanting the crop reduces the hybrid’s yield potential by 0.4 to 0.7 percent for short-season and full-season hybrids, respectively.  Delaying planting into early June increases that per day yield loss to 1.3 to 1.7 percent of the hybrid’s yield potential for short-season and full-season hybrids, respectively.

 

In a dryland cropping situation in mid-May, daily delay in replanting can result in a loss of 0.4 to 0.9 percent of the hybrid’s yield potential for short-season and full-season hybrids, respectively; whereas by early June, a delaying replanting by one day results in a 2 to 1.3 percent loss of the hybrid’s yield potential for short-season and full-season hybrids, respectively.  Dryland corn yields can be impacted even more by delayed planting than estimated by these average losses because pollination is also delayed to the hotter and drier portions of summer.

 

The first step is to determine the plant population to estimate the chances of obtaining the hybrid’s maximum yield potential.  Estimate current corn stand by counting the number of plants in a 17 ft 5 inch row length.  (For 30-inch rows, a row length of 17 feet and 5 inches is equal to 1/1000 of an acre.)  Repeat this count in 6 to 8 random locations for each 20 acre block of a field.  Average the number of plants in the 6 to 8 row lengths to determine an estimated population.  During past field trials, we saw a 1 percent decrease in yield for each 1,000 plant per acre decline in harvest population.  However, with many hybrids now planted at 32,000 to 36,000 or more plants per acre, our former trials determining yield losses with lower populations are questionable for reliability.  We suggest that you start calculating the yield loss per loss of 1,000 plants once the population falls below 32,000 since the yield increase as you go above that target is small.

 

While counting the number of plants, also observe the unevenness of the stand.  If the stand has a number of small gaps (1.5 to 3 feet in length), deduct 2 to 10 percent from the hybrid’s expected yield potential with a perfect stand.  If there are numerous gaps between plants that measure 4- to 6-feet in length, deduct 10 to 20 percent from the field’s yield potential.

 

The next step in the process is to estimate the yield potential of the stand actually in the field.  Use the stand reduction loss percentages (above) and the realistic yield goal to estimate the yield potential of the reduced stand.  This is the expected yield without replanting.  You then want to estimate expected yield if you replant.  Deduct from that the expected percentage yield loss based on the date that you expect to be able to replant the field.  If the initial stand was not planted around the ideal planting date, you may also need to adjust the realistic yield goal for the actual planting date.  Make your best guess as to when you can prepare the field for replanting (killing the existing stand), obtain new corn seed, and get back into the field to replant.  Keep in mind that the current weather pattern could easily force you to delay planting again, just like it did for the initial planting but it is best not to underestimate how long it will take to replant!

 

Next, you should calculate the replanting cost including extra tillage (equipment, fuel, and labor) if you plan on doing any tillage either to kill the remaining corn and/or to prepare the seedbed.  Add in the planting cost; seed costs; any needed pesticide costs; and, if the corn will be planted late, add in a cost for drying the corn.

 

Compare the expected yield without replanting with the expected net yield (after you deduct those additional costs involved in reseeding the stand) with replanting and decide if it is worth the effort to replant.

 

One final consideration is that you should factor in the risks involved in replanting.  Replanting corn does not guarantee that you will achieve any better a stand the second time around.  If the weather stays bad, if slugs or insects attack the crop, if poor growing conditions continue for much of the remaining season, or a hurricane, hail, or other storm damages the crop later, you may expend a great deal of money for minimal to no benefit.

 

Other considerations when deciding to replant include:

 

Sometimes, seeding alongside the rows already in the field is suggested in lieu of a full replant.  However, the plants often end up having more than a 2-leaf difference in their stage of growth and the younger plants will be at a competitive disadvantage.  Yield will likely be a lot less than expected.

 

There have been a few places where replanting is necessary and existing plants need to be killed.  The difficulty is that the corn is Roundup Ready (in additional many hybrids are also Liberty Link), so control will be difficult.  If by chance the corn is not Roundup Ready, glyphosate is the best option.  The herbicide options include Gramoxone plus atrazine, Select (clethodim), or Liberty (if not a Liberty Link hybrid).  Check the clethodim label and follow the required time between application and replanting because clethodim can cause corn injury if planted too soon.  A multi-state project conducted in this region found Gramoxone provided the most consistent control and it performed better on 5 inch corn and then corn that was 2 to 3 inches tall.  No treatment consistently controlled all the corn plants.  If complete control is necessary, tillage will be required.

 

If residual herbicides were used, you need to think about when the products were applied and at what rate.  Most of the residual herbicides will not provide more than 3 to 4 weeks of activity.  What do the labels allow regarding an additional application?  Are weeds present at time of the replanting and do they need to be killed?  Would delaying a herbicide application until the corn is up and then using an early postemergence application that includes a product that provides residual control be the best option for the replanted field?

 

If replanting occurs during May and early June, damage from cutworms, seed corn maggot, wireworms, and white grubs can continue to affect stand establishment.  The most common insect problem in later planted corn is the black cutworm.  If slugs were a problem on the first planting, weather conditions after planting will determine if they will continue to be a problem.  Rescue treatments are only available for cutworms and slugs.  The cool, wet conditions that resulted in reduced stands and poor plant growth have also slowed the development of white grubs and wireworms.  In addition, wireworms can remain in the larval stage for up to six years, depending on the species.  So you can expect them to be present when you re-plant, especially in fields with a history of wireworm problems.

Corn Planting Delayed?

Has Field Corn Planting Been Delayed—What Management Decisions Need Adjustment?

 

The Agronomy Team

(Richard Taylor, Joanne Whalen, Mark VanGessel, Nathan Kleczewski, Amy Shober, Phillip Sylvester, Cory Whaley, and Dan Severson, University of Delaware

 

The prolonged period of cold and wet weather this spring has delayed planting for many growers.  Late planting dates (roughly after May 26) offer challenges that must be successfully met to ensure the minimum impact on yield potential.  In this article, the UD Agronomy Team will outline adjustments and decisions needed to grow a successful corn crop when planting is delayed.  We’ll cover some of the management decisions and options available to help late planted corn by practice category.

 

Soil Fertility:  An important potential problem with delayed planting occurs when a portion of the required nitrogen (N) fertilizer has been applied in the weeks prior to when the corn is actually placed in the soil.  During the delay, nitrate-N added can be loss via denitrification or leaching and nitrification of ammonium or urea can begin again resulting in the loss of N if the rainfall pattern continues.  To give the process more time, ammonium or urea sources can be treated with urease and/or nitrification inhibitors such as Super U or Agrotain Plus and this can delay a significant loss of N through leaching or denitrification by three or more weeks.  Losses that do occur will require the grower to apply additional N fertilizer at an additional cost and require changes to the nutrient management plan (NMP).

 

Also along these lines, the application of manure well before planting can also permit loss of any inorganic N present in the manure.  Although the cold weather has delayed the process of mineralization there was a short period earlier this spring when air and soil temperatures rose enough to encourage mineralization and nitrification of organic N from the manure.  With additional rainfall and a return to cold temperatures, any nitrate N formed will likely be loss before the crop can grow enough to reach the stage when N uptake accelerates.  If N is lost, additional N fertilizer can be applied to the crop, but the NMP will need to be modified.

 

Although many of Delaware’s growers currently use a banded starter fertilizer and include at least some ammonium sulfate in the starter band, growers may be tempted to speed up the planting process by eliminating banded starter fertilizer.  It is true that as we move into June and if soil temperatures finally warm up, phosphorus (P) and potassium (K) will become more available to the crop and may not be needed as part of the starter fertilizer.  However, slightly higher than usual rates of starter featuring the soil mobile nutrients, N and sulfur (S), or planning on an earlier sidedress N application should help corn get off to a faster start and keep it growing rapidly during the critical V5 to V9 growth stages when kernel number and row number are being set.

 

Soil Considerations:  Although soil temperature should be increasing rapidly at this time of year, the cooler, wetter conditions we face in 2016 are preventing that increase.  The higher the soil temperature the faster and more uniform is seed germination and emergence.  Rapid germination and emergence will translate into improved yield potential.

 

Some options for the growers include the use of a turbo-till or similar tillage implement to help dry and warm the surface soil.  Although more extensive tillage could be used as well, further delaying planting to complete preparing a fine-firm seedbed is counterproductive.  In addition, extensive tillage especially on soil that is at the upper limit or past it for water content can lead to severe compaction issues.  Even with a turbo-till, the key to using it successfully will be to avoid any tillage if the soil is too wet since compaction can translate to yield losses that will continue for years.  Turbo-till and similar light tillage that warms and dries the soil surface without causing compaction issues will shorten the time until a field can be planted.  Keep in mind that this type of tillage will incorporate some of the crop residue or disturb a killed cover crop and may not be acceptable in some situations.

 

Another option is the use of aggressive row sweeps or row cleaners to clear the top of the seed row and allow the soil to warm faster.  This will allow the soil immediately over the seed to quickly warm up and dry if we receive some periods of sunny weather.  Again, warmer soil translates to more rapid and uniform emergence and higher yield potential.

 

Hybrid Selection:  Growers often start thinking of changing to shorter season hybrids as planting is delayed into early June.  Dr. Peter Thomison from Ohio State University found that a hybrid planted in late May/early June will mature at a faster thermal rate (require fewer total heat units) than the same hybrid planted in late April or early May.  He found that the required heat units from planting to kernel black layer decreased on average about 6.8 GDDs (growing degree days) per day of delayed planting so that a hybrid rated at 2800 GDDs planted at the normal time would require 204 fewer GDDs or about 2600 GDDs if planted 30 days late in late May or early June.  Dr. Thomison does point out that other factors should be considered when deciding on whether to change from a full season to a short season hybrid.  One of these considerations is that a full season hybrid although yielding more could have a significantly higher grain moisture at maturity than earlier maturing hybrids if fall weather conditions are not conducive to rapid drydown.

 

Another factor that relates to insect control is that European corn borer (ECB) damage and yield reductions are often greater even under low ECB pressure when corn hybrids are planted late.  This warrants the selection of ECB Bt hybrids whenever possible for late planted corn situations.

 

Since late planting is most likely to occur on soils that are either warmer than the temperature seen at normal planting time or will warm up much quicker as we move into June, germination and emergence will be better than that seen at the optimum planting date.  For early planting dates and optimum plant dates, we often plant 5 to 10 percent higher seeding rates than the target or desired harvest population since we expect greater seedling mortality.  For late planting, seeding rates can be decreased to about 3 percent higher than the desired harvest population and this will reduce the production cost at least a little.

 

Weed Control:  If the field has not received a burndown, you may need to adjust your standard burndown program to account for larger weeds. If residual herbicides were used ahead of the anticipated planting, you need to think about when the products were applied and at what rate.  Most of the residual herbicides will not provide more than 3 to 4 weeks of activity.  What do the labels allow regarding an additional application?  Are weeds present at time of planting and do they need to be killed?

 

Disease Issues:  Most issues with stand are caused by wet conditions.  No seed treatment will save you from plants submerged in water or growing in standing water for prolonged periods of time.  The presence of Pythium or Fusarium on roots of plants growing in wet cool soils does not mean stand loss was caused by these organisms.  Rather, stand issues were likely a complex of issues related to poor plant growth and excess water.

 

Planting into cool soils can result in more issues with pre- or post-emergent damping off due to the seeds remaining in the soil for longer periods of time or delayed seedling growth.  If you replant and stick with a 100-120 day hybrid you can end up with stalk rot or stalk strength issues later on, especially if growing unirrigated corn, because the corn may be exposed to more stressful growing conditions (hoy dry) during critical periods of plant growth.

 

Two other diseases that should be targeted for finding resistant hybrids are gray leaf spot and northern corn leaf blight.  Whether you are choosing a corn hybrid to replant or choosing a hybrid for the normal planting time, hybrids with resistance to these two diseases should be high on your list.

 

Irrigation Practices:  On late planted corn, any early moisture stress around V4 to V6 would be more critical and possibly contribute to a yield reduction.  Late planted corn is growing faster than is normally seen since there are so many heat units (GDDs) accumulating in June and early July and the soil is probably already warm.  Therefore, a grower might fail to recognize how rapidly corn roots are growing and how fast soil moisture is being depleted.  This could lead to underestimating the need for additional irrigation.  This is one aspect where moisture stress could have a larger impact on the yield of late planted corn.

 

If wet soil conditions continue into the rapid growth phase, it might become difficult to apply N via fertigation in a timely fashion.  In case this is a concern, growers could set their irrigation system to run as fast through the field as possible so the water volume is kept as low as possible while applying N fertilizer to keep the grow growing and developing without causing excessive denitrification, leaching, or root suffocation from water ponding.  This applies N almost as a foliar feed application but in a dilute enough solution that foliar burn is not likely to happen.

 

Insects and Slugs:    One of the most common insect problems in later plated corn is the black cutworm. Conditions favoring cutworm out breaks include a combination of late planted corn, poorly drained soil, heavy broadleaf weed growth, planting into soybean stubble, and reduced tillage. Even if an at planting protection method is used including at-planting insecticides, seed treatments or Bt corn, scouting after plant emergence will still be important.  If conditions remain cool and wet, wireworms and white grubs can continue to be a problem. Although problems from annual grubs tend to decrease with the warming of the soil and development of grubs from the damaging larval stage to pupation, it will still be important to sample fields for grubs before planting to determine what level and species is present and if larvae have started to pupate. Wireworms can remain in the larval stage for up to six years, depending on the species, so you can expect them to be present in fields with a history of wireworm problems. Since slugs have already hatched, the potential for slug damage will be determined by weather conditions after planting. In wet years, we have seen economic levels of damage from slugs continue through June so scouting as soon as corn is spiking is important to time a rescue treatment.

GMO Milk

Will non-GMO be the next trend?

When food products made from genetically modified organisms (GMOs) hit commercial markets in the late 1990s, many thought consumer opposition would be short lived. Now a vast majority of the nation’s corn and soybeans are GMOs, which means that milk—except for milk that’s organically produced—is also considered to be a GMO product.

The number of consumers who are buying organic food products and/or food products made without GMOs is increasing; both the organic and non-GMO food categories are seeing tremendous growth, says Sara Dorland, analyst with the Daily Dairy Report and managing partner at Ceres Dairy Risk Management, Seattle.

“Regardless of the science, 20 years after the first commercial introduction of genetically engineered (GE) crops, consumers are starting to push back, and a growing number of consumers are reaching for products with ‘clean’ labels, no artificial colors or flavors, and in some cases non-GMO,” Dorland notes. “And large food companies are starting to pay attention.”

Within the past year, Dorland notes that Kraft Foods removed artificial colors from its iconic yellow macaroni and cheese, and General Mills recently committed to labeling U.S. products that contain GMOs. Whole Foods has also said that by 2018 it will have implemented a full transparency policy on GMOs and will verify all non-GMO claims.

In late April, Dannon announced plans to transition its Oikos Greek, Danimals, and Dannon yogurts as non-GMO products starting this July. “In addition, by December 2017, Dannon, like General Mills, will label any brands that still contain genetically engineered ingredients. As larger companies look more seriously at sourcing non-GMO milk, the entire dairy industry will need to take note,” says Dorland.

While the news that the popularity of organic and non-GMO milk products is not necessarily good news for conventional milk producers, it could present an opportunity to those who are willing to change their strategy.

“For dairies converting to non-GMO milk, the overall process could be easier than switching to organic production,” Dorland notes. “Recently, the Non-GMO Project changed its rules for non-GMO milk production by reducing the conversion period from one year to 30 days, which basically reduces the amount of time a transitioning producer must sell non-GMO milk as conventional. This is a significant benefit for producers making or contemplating the switch.”

Non-GMO regulations also do not impose pasture restrictions on milk cows like those for organic milk producers. Assuming a producer does not have cloned or genetically altered cows, Dorland notes that making the switch to producing non-GMO milk is a matter of sourcing non-GMO feed.

“Readily available feed could be the limiting factor in conversion to non-GMO milk,” says Dorland. In 2015, 92% of all corn and 94% of all soybean acres were planted with genetically engineered seeds, according to USDA. For corn and soybeans to be considered non-GMO, a five-year transition period is required for crops used in livestock feed.

“That does not necessarily preclude the resulting crops from being eligible for non-GMO status during the transition period, but they must be proven to be non-GMO through testing, and the producer or farmer must demonstrate that the seeds and the crop are part of a system designed to avoid GMOs,” says Dorland. The Non-GMO Project focuses on testing feed because no reliable tests for milk exists. Organic feed also qualifies as non-GMO, but the cost of organic feed is likely higher.

If consumers are willing to pay up for non-GMO dairy products and manufacturers are willing to pay a premium for non-GMO milk, which at this point is unclear, some dairy producers will likely start looking to non-GMO production as a way to differentiate their product in what is currently an oversupplied milk market, Dorland adds.