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Friday, June 22, 2018

Continued Rainfall and Excessively Wet Field Conditions

Ryan Miller, Extension Educator - Crops, Liz Stahl, Extension Educator - Crops, Jeff Coulter, Extension Corn Agronomist, Seth Naeve, Extension Soybean Agronomist, Dean Malvick, Extension Plant Pathologist, and Fabian Fernandez, Extension Nutrient Management Specialist

It has been wet, for much of Southern Minnesota this has been one of the wettest growing seasons on record. Precipitation maps from June 12th show just how wet it has been.  In the week since these maps were published many areas have continued to see above average precipitation (see below).


The continued rainfall has made it difficult to implement postemergence weed control and has now created concerns about crop health due to saturated soils and flooded field conditions in some locations.

With the recent heavy rains, many corn and soybean fields have areas where crops are in flooded or saturated conditions. This article discusses agronomic and disease issues for corn and soybean exposed to prolonged periods of high soil moisture.

Agronomic considerations for corn

Growth and development

Although corn is at varying stages due to a wide range of planting dates this season, much corn is around the V8-V10 stage of growth.  Corn that is at less than the V6 stage of growth will be more susceptible to ponding and flooding since the growing point is still under the soil surface. 

Given the June 22nd calendar date, replanting corn is not an option.  We will have to wait and see how soil flooding affects corn mortality.   Completely submerged plants are at higher risk of mortality than partially submerged plants.  Survivability is impacted by how fast the water recedes and temperatures during the flooded conditions.  Cooler temperatures (mid-70’s or cooler) are generally better for crop survivability.  Generally corn should be able to survive a couple days of flooded conditions, but this is complicated by the fact that many spots have flooded multiple times this season.  Some root death is likely in flooded soils and new root growth will be hindered until the soil adequately dries.  Affected plants could be subject to drought stress if dry conditions follow.  

After the water recedes we will have to assess drown-out areas and determine how best to manage them.  Although accessibility to these spots may prove challenging, providing some sort of vegetative cover to aid in weed management and to help prevent fallow syndrome is recommended.  Read more on fallow syndrome and utilizing cover crops to prevent it at https://z.umn.edu/fallowsyndrome.

It may be prudent to consider more permanent vegetative cover in areas that persistently flood out.  Modern planting and spraying technology (i.e. section shut-offs) have made it easier to manage around vegetative cover.

Nitrogen management considerations

Wet soil conditions in the spring raise concerns that nitrogen (N) applied in early spring or prior might be lost. When soils become too wet, the potential for N loss is directly related to the amount of N present in the nitrate (NO3-) form. With the exception of urea-ammonium nitrate (UAN) solutions that contain 25% of the total N as nitrate, or ammonium nitrate that contains 50% of the total N as nitrate, most commercial fertilizers being used today are in the form of ammonium (NH4+) or forms that rapidly transform to ammonium (like anhydrous ammonia and urea). In the ammonium form, N is retained in the exchange sites of soil particles and organic matter.

The transformation of ammonium to nitrate, or nitrification, is done by soil bacteria that need oxygen. In fields where ammonium-based fertilizers were applied within a few days before soil conditions became excessively wet, the potential for N loss from the fertilizer is minimal as there was not enough time for the fertilizer to nitrify. Since urea is soluble in water, the only concern would be if substantial precipitation occurred soon after urea was applied in well-drained fields. In sandy soils or heavily tile-drained soils it is possible to move urea or nitrate as much as a foot for each inch of rain. On the other hand, movement is only approximately five to six inches for each inch of rain in a clay loam or silt loam soil. That said, between rain events nitrate will start to move back up as evaporation from the soil surface creates an upward suction force that moves water and nitrate closer to the surface. Similarly, evapotranspiration from actively growing crops will result in a similar suction force in addition to some nitrate uptake by the crop.

Nitrogen loss will occur in fields where N from fertilizer or organic N from the soil was present in the nitrate form before the soils became excessively wet. In fine-textured soils, water-saturated conditions cause N lost through denitrification. Denitrification rates increase after about a day under oxygen-depleted conditions that result when soil pore space is filled with water. Under these conditions, soil microbes utilize nitrate for respiration, and N is released as a bi-product in gaseous forms that are lost to the atmosphere. For each day the soil remains saturated with water under warm soil temperatures, it is possible to lose as much as 5% of the nitrate-N in the soil.
 
In coarse-textured soils or soils intensively tiled, N loss occurs mostly by leaching below the root zone or into tile lines.


Figure 1. Early N deficiency













Figure 2. Poorly developed canopy due to N deficiency














Nitrogen deficiency is characterized by yellowing along the leaf midribs, starting at the leaf tip and moving toward the stalk (Figure 1). Nitrogen deficiency will first be observed on the lowest leaves of the plant. The chlorotic areas will turn brown as the season progresses (Figure 2). Severe N deficiency will result in a poorly-developed crop canopy that will be unable to intercept all of the sunlight during grain fill. Nitrogen-deficient leaves also have a lower capacity for photosynthesis, further limiting the potential for grain fill.

Nitrogen uptake by corn from emergence through the V6 (six leaf collar) stage only represents about 5% of the total plant uptake. However, starting at about the V8 (eight leaf collar) stage, there is rapid accumulation of N by the plant, with about 60% of the total N uptake occurring between V8 and silking. Thus, it is important that N-deficient areas are detected early, and that supplemental N is sidedressed on these areas as soon as possible.

To determine whether supplemental N should be applied in corn, consider the U of M supplemental nitrogen worksheet for corn. For entire fields or portions of fields meeting the requirements for supplemental N, this worksheet recommends a rate of 40 to 70 lb N/ac, depending on the situation.  Additional information on N management during this difficult growing season can be found in a recent Minnesota Crop News, Sidedressing Nitrogen in this Challenging MN Growing Season.

Agronomic considerations for soybean

Although soybean is generally sensitive to excess water, soybeans can survive underwater for a week or more under ideal conditions. Typically soybeans tolerate 48 hours under water quite well, but flooding for 4 to 6 days can reduce stands, vigor, and eventually yield. Many factors determine how well a soybean crop will tolerate flooding. The most important factors that determine the fate of flooded soybean fields are: 1) duration of the flooding, 2) temperature during the flooding, 3) rate of drying after the flooding event, and 4) growth stage of the crop during the flooding.

Yield losses are seldom noted in fields flooded for 48 hours or less. Four days or more of flooding stresses the crop, delays the plants' growth, and causes the plants be shorter with fewer nodes. Flooding for 6 days or more can depress yields significantly, while flooding for a week or more may result in significant (or entire) losses of stand.

Temperature during the flooding event plays a large role in determining the fate of a submerged soybean field. Higher temperatures cause the soybean plant to more quickly deplete its stored energy. Additionally, soybean plants appear to be very sensitive to high carbon dioxide (CO2) levels in the soil. Higher temperatures cause plants and soil microbes to respire at high rates that quickly deplete the water of oxygen and increase CO2 levels. Cool, cloudy days and cool clear nights greatly increase the survivability of a submerged soybean crop.

The rate of field drying after a flooding event also plays a large role in soybean survival (Sullivan et al, 2001). Also, researchers have found yield reductions to be much greater on flooded clay soils than on silt loam soils when flooded for the same period of time (Scott et al, 1989). At the V4 stage, these researchers reported yield losses of 1.8 bu/ac per day of flooding on a clay soil and 0.8 bu/ac per day on a silt loam soil. The effects of flooding are even more detrimental during the reproductive phases of development. For example, flooding at the R1 stage caused yield losses of 2.3 and 1.5 bu/ac per day on clay and silt loam soils, respectively. Even larger yield losses would be expected in soybeans at the R3 to R5 stages.

Some of the main indirect effects of flooding on soybean yields are: 1) root diseases, 2) N deficiency, 3) and other plant nutrient imbalances. Caring for recuperating soybean stands should focus on reducing crop stresses where possible. For example, cultivation should be considered to increase soil aeration and herbicide stress should be minimized or postponed where possible.

Flooded and wet soil conditions increase risk of corn and soybean seedling diseases

Saturated soil conditions may lead to significant seedling diseases in soybean and corn.  Wet and flooded soils are especially favorable for the soilborne, moisture-loving pathogens Pythium and Phytophthora. Pythium appears to cause most damage to seedlings of soybean or corn, and Phytophthora can damage soybean seedlings or start infections in the early summer that may develop and kill soybean plants later in the summer. Cool, wet, soils can also favor sudden death syndrome, with is caused by the soilborne fungus Fusarium virgulifome (previously named Fusaium solani f.sp. glycines).  For more information on soybean and corn diseases, please visit the Minnesota Crop Diseases web site  (https://z.umn.edu/cropdiseases).

References


Ritchie, S.W., J.J. Hanway, and G.O. Benson. 1997. How a corn plant develops. Iowa State Univ. Coop Ext. Serv. Spec. Rep. 48. Iowa State Univ., Ames.

Scott, H.D., J. DeAngulo, M.B. Daniels, L.S. Wood. 1989. Flood duration effects on soybean growth and yield. Agron J. 81:631-636.

Sullivan, M., T VanTooai, N. Fausey, J. Beuerlein, J. Parkinson, A. Soboyejo. 2001. Evaluating on-farm flooding impacts on soybean. Crop Sci. 41:93-100.

Wednesday, June 20, 2018

Hay Auction June 7, 2018

by Randy Pepin, UMN Extension Educator, Stearns, Benton, and Morrison Counties
pepin019@umn.edu or (320) 333-1369

Keeping up with current hay prices is important for most livestock farmers. We calculate price averages, quality averages, and the corresponding ranges of the various hay lots from recent hay auctions in Sauk Centre, MN. We also keep an updated history of recent years of some selected hay lots and create graphs of four different quality types of medium square alfalfa bales. This is posted every month, about a week after the last auction of the month.

Managing Micronutrients

Seth Naeve, Austin Dobbels and Dan Kaiser cover micronutrients in this episode. Dive into BMPs and diagnosis, plus a special focus on iron deficiency chlorosis.

Tuesday, June 19, 2018

Evaluating responses of soybean to foliar fungicides in Minnesota

Bruce Potter, Extension IPM Specialist and Dean Malvick, Extension Plant Pathologist

Why worry about the disease control benefits of fungicides?

Soybean growers and their advisors are faced with a bewildering array of information, from many sources, about products and practices that might increase yield and profits. Management of soybean diseases is no exception. Foliar fungicides are valuable soybean disease management tools. However, when applied in the absence of controllable, yield-limiting plant disease, they are typically not a profitable input.

Monday, June 18, 2018

As June transitions into July what soybean weed management options are still available?

Jeffrey L. Gunsolus Extension Agronomist-Weed Science

waterhemp in soybean field
Waterhemp in soybeans. Photo: Liz Stahl
The combination of a long duration of wet weather and advanced growing degree days has created serious weed management challenges for many corn and soybean growers. Due to the impending June 20th cutoff date for approved dicamba formulations on Xtend soybean and weeds moving into their rapid growth phase, most of the questions I am receiving, and I hope to address, are focused on soybean.

Friday, June 15, 2018

Are Inversions Really That Common?

by Andrew Thostenson, Pesticide Program Specialist, North Dakota State University Extension Service; Jared Goplen, David Nicolai and Ryan Miller, University of Minnesota Extension Educators - Crops

Pesticide applicators have long been obliged and directed by pesticide labeling to understand, identify, and NOT apply during air temperature inversions. This has become acutely important because of the off-target movement of dicamba over the last couple of years. But a similar statement is also found on many other pesticide labels. 

EPA and pesticide manufacturers have made it abundantly clear they do not want pesticides applied during an inversion. But that is easier said than done. Until recently, very few people actually monitored inversions. That is fast changing. North Dakota and NW Minnesota via NDAWN now have 31 stations monitoring this in real time with alerts being posted to smart phones. Missouri has 11 stations. Pesticide manufacturers have also spent a fortune on predictive modeling and distribution of their estimates via mobile apps. Finally, hand held sensors developed by Innoquest are also widely available. Now that we can measure and monitor for inversions, an applicator has to assess this information and make a decision to spray or NOT spray. That is the hard part. 

Winter Camelina Field Day to be held June 27 in Waseca

The University of Minnesota Forever Green Initiative and the Agricultural Utilization Research Institute (AURI) invite processors, food entrepreneurs, culinary professionals, farmers, and the curious public to an open house event at the Southern Research and Outreach Center 35838 120th Street Waseca, MN. Throughout the event, scheduled for June 27, 2018, attendees will learn about winter camelina, an exciting new oilseed crop currently in the research and development phase, which has the potential to transform food, fuel and feed in Minnesota.

Register today for the July 2018 Field School for Ag Professionals

By Dave Nicolai, IAP Program Coordinator

The 2018 Field School for Ag Professionals will be held on July 25 - 26 at the University of Minnesota Agriculture Experiment Station on the St.Paul campus at the University of Minnesota. The Field School for Ag Professional is a summer training opportunity that combines hands-on training and real world field scenarios. The two-day program focuses on core principles in agronomy, entomology, weed and soil sciences on the first day to build a foundation for participants; and builds on this foundation with timely, cutting-edge topics on the second day.

Thursday, June 14, 2018

Small Grain Summer Plot Tours

by Jared Goplen, Extension educator and Jochum Wiersma, Extension small grains specialist
People in wheat field

University of Minnesota Extension is offering four Small Grain Summer Plot Tours across MN in June and July to address small grain production issues, variety performance, and insect and disease pests.

These programs are designed to provide farmers and crop consultants the tools needed to make small grains successful and profitable. This includes information on production agronomics, variety selection, disease identification, fungicide use, fertility, and economics. These programs are interactive and discussion based, featuring a tour of current research plots and discussion of on-farm experiences.

Wednesday, June 13, 2018

Corn and soybean weed management tour scheduled for July 3

Lisa Behnken and Ryan Miller, Extension educators
People on field tour

Weed management has changed dramatically in recent years with herbicide resistant weeds, new herbicide technologies and challenging weather conditions. How do we develop resilient strategies to deal with all of the different challenges? The 2018 Corn and Soybean Weed Management Tour will highlight ongoing research that addresses these challenges and introduces new ideas for crop producers and Ag Professionals on Tuesday, July 3.

Cutoffs for postemergence herbicide applications in corn and soybean

By Liz Stahl and Dave Nicolai, Extension Educators - Crops

A late start to the planting season, combined with warm temperatures and an abundance of moisture in areas of the state has led to quick crop emergence, and crops that are rapidly advancing through the growth stages. Crops may also be in a range of growth stages due to varying planting dates that resulted from working around a wet planting season. Almost all herbicide labels have a maximum growth stage and/or crop height after which applications should not be made. Application restrictions exist to help prevent potential crop injury, herbicide carryover, environmental or food safety concerns, or other potential issues.

Heavy seedcorn maggot infestations reported in some Minnesota soybean fields

by Robert Koch (Extension Entomologist) and Bruce Potter (Extension IPM Specialist)

Some fields in Minnesota have experienced significant stand loss caused by seed corn maggot. In a field in Dakota County (southeast Minnesota), research plots planted in the last week of May with untreated soybean seed incurred greater than 90% stand loss. This field had none of the typical risk factors for infestation by seedcorn maggot, except for likely planting during a period of fly activity. In addition, a report was received of a central Minnesota soybean field with seedcorn maggot injury. Portions of the neighboring fields had some seedcorn maggot injury as well. It turns out, that this field had been planted to sweetcorn in 2017, but the field was passed and not harvested. The resulting decaying sweet corn may have attracted egg-laying adults last fall and subsequently supported a very large population of overwintering pupae. Soybean planting into the still decaying sweet corn this spring was likely timed well with fly emergence and egg laying. As you perform early season scouting of your fields, keep seedcorn maggot in mind if you start to observe issues with plant emergence. Below, we provide an overview of the pest's identification, biology and management.
Injured cotyledons from an infested soybean field, and seedcorn maggot larvae and pupae collected from injured plants and soil near the injured plants.

Tuesday, June 12, 2018

No change in the June 20, 2018 dicamba application cutoff date for Xtend soybeans

Jeffrey L. Gunsolus, Extension Agronomist - Weed science

On June 8, 2018 the Minnesota Commissioner of Agriculture released a letter to stakeholders indicating that the MDA will be keeping the 24(c) restrictions for XtendiMax, Engenia and FeXapan in place for 2018. The Commissioner’s letter also explains the rational for holding to the 24(c) restrictions, despite the challenges presented by late planting dates for soybean in many parts of the state.

Sidedressing Nitrogen in this Challenging Minnesota Growing Season


Fabian G Fernandez, Nutrient Management Specialist

Most corn in Minnesota is between V3 and V8 and developing rapidly now with most fields around V5-V6. Up to this point corn has taken up around 20 to 25 lbs N/acre. That’s about 10 percent of the total N it will need by the time it reaches physiological maturity in the fall.

Herbicide drift symptomology

by Ryan Miller, Extension educator

dicamba damage in soybean
Dicamba damage in soybean
As we enter peak postemergence herbicide application season, there is an elevated risk for off target herbicide movement. Of particular concern is the movement of growth regulator herbicides onto soybeans. Growth regulator herbicides include products like 2,4-D and dicamba. These products cause leaf puckering, and epinasty or twisting of stems. Injury symptoms are most commonly observed on the newest most recent growth in soybeans.

Thursday, June 7, 2018

IPM Podcast: Update on Recent Corn Rootworm Activity and Bt Resistance Trends in Minnesota

Welcome to the 3rd IPM Podcast for Field Crops – this Podcast is sponsored by the UMN Extension Integrated Pest Management (IPM) Program.


Corn rootworm larvae feeding damage to corn roots. Photo: Dave Hansen
The purpose of the IPM podcasts is to alert Growers, Ag Professionals and Educators about emerging pest concerns on Minnesota Field Crops - including corn, soybean, small grains and alfalfa. We also review recent pest trends and research updates.

Wednesday, June 6, 2018

Nutrient Management Podcast: Mastering the Pre-sidedress Nitrate Test


The pre-sidedress nitrate test (PSNT) is a tool for making decisions on supplemental nitrogen application. Taken during June prior to side-dress N application around the V6 stage of corn growth, the PSNT offers a way to assess insufficient N in the soil. It offers guidance for efficient N management, but only if carried out correctly. Listen as guests Dan Kaiser, Fabian Fernandez, Brad Carlson and Jeff Vetsch talk through how to effectively use the PSNT to manage nutrients on your farm.

Monday, June 4, 2018

Refocusing attention on the most yield limiting pathogen of soybean

Angie Peltier, Phillip Glogoza, Jared Goplen and Seth Naeve (University of Minnesota Extension) and Sam Markell (North Dakota State University Extension)

Minnesota map of soybean cyst nematode spread
Figure 1. Soybean cyst nematode identification and spread in Minnesota
What causes an estimated 90,000,000 bushel yield loss of soybean in the North Central U.S. each year? What can cause an eye-popping 30% yield loss without above-ground symptoms? What can move any way that soil moves? What can invade a soybean plant and worsen brown stem rot and sudden death syndrome symptoms?

The answer to each question is the same: the soybean cyst nematode (SCN). SCN is a microscopic roundworm that was first found in the U.S. in North Carolina in 1954. SCN has since moved north and west, reaching southern Minnesota in 1978. Little by little SCN continues to spread, marching north in the state along with soybean production, cutting soybean yield-potential along the way (Figure 1).

Alfalfa Scissor Cuts May 31 & June 1, 2018

by Randy Pepin, UMN Extension Educator, Stearns, Benton, and Morrison Counties
pepin019@umn.edu or (320) 333-1369

Harvesting high quality alfalfa hay is a prime concern of most dairy farmers.  The ideal time to cut first crop alfalfa has many variables such as: spring weather, severity of the winter, the weather last fall, how the field was managed last fall, age of the alfalfa stand, alfalfa variety, fertility level, and each farmers criteria on desired hay quality.  Collecting a series of scissor cuts samples of an alfalfa stand beginning early in the growth stage will monitor the progress of the alfalfa maturity.  We harvest scissor cuts on a number of fields throughout central Minnesota to help dairy producers observe the maturing progress across several fields.

Friday, June 1, 2018

Tips and Tricks for the Pre-Sidedress Nitrate Test

Brad Carlson, Fabian Fernandez, Jeff Vetsch and Dan Kaiser are on this episode talking about the PSNT: pre-sidedress nitrate test. We cover when to take it, how to take it, why to take it and how to get it ready for the lab. Plus tips on what to do with banded fertilizer and how to translate results into management practices.

Here's What the Research Says About Managing Sulfur in Soybeans


Daniel Kaiser, Nutrient Management Specialist
Jeff Strock, Professor

Soybean plants need sulfur to complete their lifecycle. It’s a key component of amino acids and deficiency can affect soybean concentration and grain yield. While sulfur provides all these benefits to the soybean crop, research shows that the best way to manage sulfur in soybeans is not to apply fertilizer S directly to soybeans, but to corn in a corn-soybean rotation.

Off-target herbicide movement

by Ryan Miller, Extension educator

Tractor spraying in field
Photo: Liz Stahl
As we are all well aware, last year saw the addition of dicamba tolerant soybeans to weed management options in the U.S. The addition of this technology was not without the troubles of off target movement and subsequent plant injury.

This led to changes in the federal label for all brands of dicamba that can be applied to dicamba tolerant soybeans.

Alfalfa Scissor Cuts May 28-29, 2018

by Randy Pepin, UMN Extension Educator, Stearns, Benton, and Morrison Counties
pepin019@umn.edu or (320) 333-1369

Harvesting high quality alfalfa hay is a prime concern of most dairy farmers.  The ideal time to cut first crop alfalfa has many variables such as: spring weather, severity of the winter, the weather last fall, how the field was managed last fall, age of the alfalfa stand, alfalfa variety, fertility level, and each farmers criteria on desired hay quality.  Collecting a series of scissor cuts samples of an alfalfa stand beginning early in the growth stage will monitor the progress of the alfalfa maturity.  We harvest scissor cuts on a number of fields throughout central Minnesota to help dairy producers observe the maturing progress across several fields.

Thursday, May 31, 2018

IPM Podcast: Early Season Weed Control in Corn and Soybeans

Welcome to the second in a series of IPM Podcasts for Field Crops – this Podcast is sponsored by the UMN Extension Integrated Pest Management (IPM) Program.

giant ragweed
Giant ragweed seedlings. Photo: Lisa Behnken
Our goal with these Podcasts is to alert Growers, Ag Professionals and Educators about emerging pest concerns on Minnesota Field Crops - including corn, soybean, small grains and alfalfa - and offer some useful pest management strategies. This podcast was hosted by Bill Hutchison, Coordinator of the MN IPM Program,  Dave Nicolai, Crops Extension Educator & Coordinator for the Extension Institute for Ag Professionals and Ryan Miller Crops Extension Educator based at Rochester, MN. Special thanks to Anthony Hanson, Extension Post-Doctoral Associate in Entomology for the recording technical assistance.

The Color Yellow

Although not nearly as heart-wrenching as the novel 'The Purple Color', Memorial Day weekend is often the time that the color yellow is a cause for concern in spring wheat, barley, and oats.  This year is no exception. The cause in this time doesn't appear to early-season tan spot just yet but more so heat canker. The hot and windy weather this past weekend were ideal conditions to cause this physiological phenomenon.  More details about early season yellowing in general and heat canker specifically can be found here and here.


Wednesday, May 30, 2018

Why Is My Rye Short?

Rye is generally known as being unwieldy tall and prone to lodging.  Yet this spring the crop appears to be extremely short with some of the earliest crop already heading while just being knee high. What gives?

The much shorter crop is an outflow of the very cool months of March and April.  The very late spring has resulted in very little (vegetative) regrowth this spring.  Now that spring finally has arrived, its photoperiod response in combination with high temperatures is forcing the rye crop to immediately transition to reproductive growth, resulting in a very short crop. 

What is photoperiod sensitivity?  Photoperiod sensitivity is an evolutionary adaptation to avoid adverse conditions.  Flowering plants use photoreceptor proteins to sense changes in night length rather day length and use this information to transition from vegetative to reproductive growth, i.e. flower. Long-day plants flower when the night length falls below their critical photoperiod.

The progenitors of modern wheat, barley, oats, and rye were all long-day plants.  This ensured that the crops would flower, set seed, and mature before (extreme) the summer heat and drought of the dessert or frost in the mountain plateaus in the centers of origin could threaten the viability of the next generation. Amongst the cereals, rye has probably the strongest photoperiod response, as it is most adapted to northern latitudes, where a strong photoperiod response is most advantageous.

If you are interested in learning more about rye production, including hybrid rye, I encourage you to attend one of the field days that will be held across the state this coming month. The first field day will be held next week Tuesday from 10:00 – 12:00 at Anthony Farms (42505 Co Rd 15, St Peter, MN) in collaboration with KWS.  The University of Minnesota’s Small Grains Summer Plot Tours stops near LeCenter and Kimball will include rye as well.  Details about those plot tours are forthcoming.


Tuesday, May 29, 2018

Central MN Hay Auctions May 2018

by Randy Pepin, UMN Extension Educator, Stearns, Benton, and Morrison Counties
pepin019@umn.edu or (320) 333-1369

Keeping up with current hay prices is important for most livestock farmers. We calculate price averages, quality averages, and the corresponding ranges of the various hay lots from recent hay auctions in Sauk Centre, MN. We also keep an updated history of recent years of some selected hay lots and create graphs of four different quality types of medium square alfalfa bales. This is posted every month, about a week after the last auction of the month.

Saturday, May 26, 2018

Alfalfa Scissor Cuts May 24-25, 2018

by Randy Pepin, UMN Extension Educator, Stearns, Benton, and Morrison Counties
pepin019@umn.edu or (320) 333-1369

Harvesting high quality alfalfa hay is a prime concern of most dairy farmers.  The ideal time to cut first crop alfalfa has many variables such as: spring weather, severity of the winter, the weather last fall, how the field was managed last fall, age of the alfalfa stand, alfalfa variety, fertility level, and each farmers criteria on desired hay quality.  Collecting a series of scissor cuts samples of an alfalfa stand beginning early in the growth stage will monitor the progress of the alfalfa maturity.  We harvest scissor cuts on a number of fields throughout central Minnesota to help dairy producers observe the maturing progress across several fields.

Friday, May 25, 2018

Will Wheat Catch Up to the Calendar?

Jochum Wiersma and Michelle Meijer

A few weeks ago, I was asked whether the wheat crop would catch up in its growth and development now that planting was delayed compared the last few years.  To explore this question we went back into the NASS crop progress reports between 1990 and 2017 and gleaned the date that seeding commenced, reached the halfway mark, and was near completion in Minnesota.  We then used those three dates to calculate the heading date using the Fargo NDAWN station.

Figure 1 shows the three regression lines that resulted from this exercise.  The blue line represents how much quicker the spring wheat cropped reached heading when planting was delayed from April 1 through the end of the month of April. The green line represents how much quicker the cropped reached heading when planting was between April 15 and May 15 and the red line represents how much quicker the crop reached heading when planting was delayed from the beginning of May through early June.  Each of the three regression lines explained about 80% of the observed variation in the data.

Figure 1 - Number of days to heading for an early, average, and late planting dates for each year between 1990 and 2017 using the NASS crop progress reports and NDAWN weather record for Fargo, ND.

The loss of the number of days to heading, i.e. the faster the pace of development as planting is delayed, is most severe in the first period and the least severe in the last period.  This may seem a bit counter-intuitive but think of it this way – in early April the average temperatures are much lower than in early May or June and thus fewer growing degree days are accumulated each day. Planting delays will move the crop into a time period where the average differences in daytime high temperatures and nighttime lows are smaller when compared to the previous two week period. 

So what does this mean in terms of actual heading date?  Using the three regression lines, a crop seeded in April 1st near Fargo is expected to head on June 10th, while a crop seeded on May first will head on June 22nd. The difference of a month in seeding date is reduced to less than two weeks.


How does this correlate to yield? The relationship with yield is less clear than with days to heading.  In the same analysis, the yield loss was about ¾ bushel per day of planting delay when using the mid-point planting date data set but the model only explained about 10% of the observed variability.  This suggests that yield potential is reduced as planting is delayed but that weather conditions during grain fill (i.e. nighttime and daytime temperatures) and absence or presence of disease (remember the early nineties are included in this data set) have more to do with the final yield than the fewer number of days to heading.

Alfalfa Scissor Cuts through May 23,2018

by Randy Pepin, UMN Extension Educator, Stearns, Benton, and Morrison Counties
pepin019@umn.edu or (320) 333-1369

Harvesting high quality alfalfa hay is a prime concern of most dairy farmers.  The ideal time to cut first crop alfalfa has many variables such as: spring weather, severity of the winter, the weather last fall, how the field was managed last fall, age of the alfalfa stand, alfalfa variety, fertility level, and each farmers criteria on desired hay quality.  Collecting a series of scissor cuts samples of an alfalfa stand beginning early in the growth stage will monitor the progress of the alfalfa maturity.  We harvest scissor cuts on a number of fields throughout central Minnesota to help dairy producers observe the maturing progress across several fields.

Thursday, May 24, 2018

2018 Field School for Ag Professionals

By Dave Nicolai, IAP Program Coordinator

people-standing-in-field
Agronomy training available this summer at the University of Minnesota Extension's 2018 Field School for Ag Professionals

The 2018 Field School for Ag Professionals will be held on July 25 - 26 at the University of Minnesota Agriculture Experiment Station in St. Paul. Field School for Ag Professional which is the summer training opportunity that combines hands-on training and real world field scenarios. The two-day program focuses on core principles in agronomy, entomology, weed and soil sciences on the first day to build a foundation for participants; and builds on this foundation with timely, cutting-edge topics on the second day.

Integrated Pest Management Podcast: Black Cutworm Alert, Reporting Network - 2018

Welcome to the first in a series of IPM Podcasts for Field Crops – this Podcast is sponsored by the UMN Extension Integrated Pest Management (IPM) Program.


Black cutworm damage to a young corn plant. Photo: W.M. Hantsbarger, Bugwood.org
Our goal with these Podcasts is to alert Growers, Ag Professionals and Educators about emerging pest concerns on Minnesota Field Crops - including corn, soybean, small grains and alfalfa - and offer some useful pest management strategies. The podcast is hosted by Bill Hutchison, Coordinator of the MN IPM Program and Dave Nicolai, Crops Extension Educator & Coordinator for the Extension Institute for Ag Professionals.

Wednesday, May 23, 2018

Prevented plant resources

Dave Bau, Extension educator

wet-unplanted-field
Heavy spring rains resulting in flooded fields have delayed planting for many farmers in southern Minnesota. Many of these farmers will have to decide what to do when the final planting dates of May 31 for corn and June 10 for soybeans.

The USDA’s Federal Crop Insurance Corporation policies have prevented planting provisions for payment if planting cannot occur before the final plant date. There are also options to plant after the final planting date, but with reduced insurance coverage.

For most of Minnesota, the final planting date for corn is May 31. It is May 25 for northern counties. The final planting date for soybeans in Minnesota is June 10. The late planting period extends for 25 days after the crop's final planting date. At this point the insurance coverage is reduced to 55% for corn and 60% for soybeans.

Assess your risk for fertilizer N loss and manage N application decisions with late planting

Brad Carlson, Extension educator

Continued wet weather and increasing temperatures in southern Minnesota are raising concerns about potential nitrogen fertilizer loss. Extension Educator Brad Carlson discusses how the risks of nitrogen loss differ with fall vs. spring applications, weather conditions and sources in the new video, Spring 2018 nitrogen concerns.

Tuesday, May 15, 2018

Soybeans and the Spring of 2018: One for the books

Seth Naeve, Extension soybean agronomist

wet-field
Photo: Liz Stahl
Spring came late to all of Minnesota, but for farmers in Southern Minnesota, it came with too many May showers. This has made #Plant18 an especially tough one for farmers in the region. Many seasoned farmers have reported that this will be the latest start in their long memories.

It is natural to feel anxious and frustrated with the weather, but it’s important to know that fields will get planted and yields can still be quite good. For the most part, farmers should proceed as normal when windows of good weather allow.

Central MN Hay Auctions April 2018

by Randy Pepin, UMN Extension Educator, Stearns, Benton, and Morrison Counties
pepin019@umn.edu or (320) 333-1369

Keeping up with current hay prices is important for most livestock farmers. We calculate price averages, quality averages, and the corresponding ranges of the various hay lots from recent hay auctions in Sauk Centre, MN. We also keep an updated history of recent years of some selected hay lots and create graphs of four different quality types of medium square alfalfa bales. This is posted every month, about a week after the last auction of the month.

Corn Fertigation: How Much and When?

Anne Struffert, Extension Educator
Fabián Fernández, Nutrient Management Specialist

In the Central Sands of Minnesota, planting is under way. With a week of warm and windy weather, things are drying out and warming up quickly. While most growers have made decisions on variety and tillage, one thing you may not have nailed down is when and how many times should you fertigate nitrogen on corn.



Loss potential in the spring is almost always high on sandy soils. With a combination of snow melt, excess rain, and a crop that is not yet needing much water or nitrogen, much of the nitrogen that we apply can leach out of the profile because it has nothing to hang on to. Because of this we suggest delaying any nitrogen application until the V2 development stage. If you need a little peace of mind and want to apply 10 to 20 pounds at planting, that is fine, just remember to keep that rate low.

Thursday, May 10, 2018

Soil compaction: What can you do?

by Jodi DeJong-Hughes, Extension educator

emerging corn
As you head back into the fields this spring, plan to reduce your soil compaction. As the weight of farm tractors and field equipment becomes larger and heavier and as the annual precipitation increases in Minnesota, there is a growing concern about soil compaction.

Here's How to Select the Right Starter Fertilizer for Corn


Daniel Kaiser, Nutrient Management Specialist
Jeff Vetsch, Soil Scientist

We had a late start to the season, and planting is later than usual. Should you use a starter fertilizer? The answer to that question is that it depends. Some research has shown later plantings will still benefit from starter due to decreasing time to silking. Decreasing the rate applied may be an option to speed up planting if you are questioning whether to keep using starter. There is no right or wrong answer whether to use starter or not in your production system. If you do choose starter here are five tips which may help you get the most out of your investment.

Tuesday, May 8, 2018

Large influx of black cutworm moths arrive in Minnesota

by Bruce Potter, Integrated pest management specialist

Minnesota map
Figure 1. Maximum black cutworm moth captures by county April 27 - May 4, 2018.
The past week brought rain and black cutworm (BCW) moths to many trap locations, both unwelcome. This is as large and widespread early-season influx of moths as we have seen for several years.

Many counties have more than one trap operating. The reported maximum 2-night moth capture for all traps in a county during the week are shown in Figure 1.

Table 1 shows counties that reported significant (numbers indicating potential risk for economic damage to row crops) captures and dates.

Thursday, May 3, 2018

Gearing Up for the Use of Dicamba Tolerant Soybean Technology in 2018

Andrew Thostenson, Pesticide Program Specialist, North Dakota State University and Liz Stahl, Extension educator

tractor-in-field
Note: Andrew Thostenson, Pesticide Program Specialist with North Dakota State University, recently posted the article “Gearing Up for the Use of Dicamba Tolerant Soybean Technology in 2018.” He discusses some very good points pertinent to Minnesotans, considering the delayed start to planting this season, in his article reprinted below.

Wednesday, May 2, 2018

Do you still need training or certification to apply dicamba?

For the 2018 growing season in Minnesota, there is a special training needed to use the new dicamba products. Specifically, these dicamba products are: Engenia®Herbicide, FexapanTM Herbicide plus VaporGrip® Technology, and Xtendimax® with VaporGrip® Technology.

If you haven’t been trained yet this year for dicamba, or if you still need to be certified or licensed to use Restricted Use Pesticides, this information will help you get started.

Tuesday, May 1, 2018

Respirator fit testing resources in Minnesota

Certain pesticides and agrochemicals require handlers to wear a respirator. In order to safely wear a respirator, you must be fit tested to make sure that the respirator fits to your face correctly. Fit testing can be hard to find in Minnesota; the following map shows locations around the state that are offering fit testing to farmers. 

Monday, April 30, 2018

Forage topics for spring: Alfalfa assessment, establishment and emergency forages

by M. Scott Wells, Forage agronomist

Assessing alfalfa

taproots-on-shovel
Healthy alfalfa taproot on the left and damaged taproots on the right
A number of factors can contribute to winter damage of an alfalfa stand. These are all important to consider as spring assessments are made. The following elements may all play a role in winter survivability. As management options are considered, remember that injured alfalfa stands can exhibit delayed regrowth, but may be capable of recovering. Be careful not to rush into alternative options if the stand can be maintained for acceptable production.

Alfalfa assessment: Factors leading to winter injury

Emergency forages: Warm season grasses

grass-plots
Emergency forages at Rosemount, 2014.
In an effort to maximize forage production during the relatively short growing seasons of the upper Midwest, semi-dormant alfalfa varieties have been heavily promoted and widely adopted, which can increase the chance of winter injury and winterkill. During the 2012-2013 winter, significant acres of alfalfa in the state of Minnesota experienced winter injury and winterkill.

In years where alfalfa is injured by the winter and cool, wet springs persist, options to replant both annual row crops and forages can become more limited. Warm season grasses could provide an alternative emergency forage during such years.

Emergency forages: Warm season grasses

Alfalfa establishment

Since alfalfa production spans several years, it is important to start off with the highest productive stands possible. The UMN Forage Team adheres to the six following management strategies for optimal alfalfa establishment: (i.) field selection, (ii.) fertility management, (iii.) seeding dates, (iv.) field preparations and seeders, (v.) seeding depth, (vi.) seed-to-soil contact, and (vii.) seeding rates.

Alfalfa establishment
2017 Alfalfa Field Crop Trials Results


For more information, visit the University of Minnesota's Forage production website.

Friday, April 27, 2018

Answers to 5 Spring Nitrogen FAQs


Fabian Fernandez, Nutrient Management Specialist
Jeff Vetsch, Soil Scientist
Brad Carlson, Extension Educator

After crazy weather in early spring, it’s finally time to get out in the fields. We’ve gotten a lot of questions about spring nitrogen lately. Here are the frequently asked questions we get about nitrogen management this time of year.

Thursday, April 26, 2018

To treat or not to treat: Should fungicidal seed treatments be applied to small grain seed this year?

Madeleine Smith, Extension small grains pathologist

field-with-spotty-wheat-stand
Root rots causing poor stand establishment in wheat. Photo: A. Friskop
At this time of year decisions are being made about whether to treat small grains seed with fungicide or insecticidal seed treatments before planting.

Fungicides applied on seed can help protect stand establishment if there are fungal diseases present in the soil, or if seed saved from the previous season is infected with Fusarium head blight or smuts. Infection by fungal pathogens at or just after germination can cause seedling loss. If seedlings do not die, they can have poor vigor, due to the inability to efficiently take up water and nutrients.

Monday, April 23, 2018

Don't compromise on best practices for rotating alfalfa to corn when field work is delayed

By Jeff Coulter, Extension Corn Agronomist

corn in field
There are many advantages to planting corn after alfalfa, including greater yield potential, reduced nitrogen needs from fertilizer or manure, and reduced pest pressure compared to when corn follows other crops. The degree to which these and other benefits are achieved is contingent upon successful termination of alfalfa, as alfalfa can greatly complete with corn for water and nitrogen. Therefore, avoid compromising on best practices when rotating alfalfa to corn, even when spring field work is delayed.

Calibrating Your Grain Drill

In last week’s post, I mentioned that small grain seeding rates should be increased once we are past the optimum time to offset the loss of tillers and ultimately reduced yield potential caused by the delayed planting date.  Consequently, you need to recalibrate your drill. Recalibrating your drill every spring is a good practice anyway as seed size and weight of different seed lots vary year-over-year and among varieties.

Modern air seeders and drills with central seed metering are relatively easy to calibrate and your user manuals have detailed instructions on how to calibrate them.  Older double disk drills are a little different story and the seeding rate tables seeding rate tables found in your operator's manual or on the inside of the seed hopper lid are a guideline at best.

Calibrating your drill in the yard is an easy way to take the guesswork and some of the stress out of it prior to getting in the field.  By measuring the circumference of the press wheel or drive wheel and then turning the wheel a certain number of times we can calculate the distance traveled.  This number multiplied by the row spacing gives the area seeded.  Catching and weighing the seed dropped by a few of the metering wheels will then allow you to calculate the seeding rate in lbs. per acre for each lot. 

The Samuel Roberts Noble Foundation from Oklahoma created a useful YouTube video that explains the steps described above very well. A cover story in Prairie Grains issue 7 describes how the Ramstad brother from Ada built a device that hooks an electrical motor on the drill frame to drive the press wheel the correct number of revolutions.



Friday, April 20, 2018

Weather Delays Corn Planting but Optimal Window Remains Open

By Lizabeth Stahl, Jeff Coulter, and Dave Nicolai

Much of Minnesota has been covered in snow past mid-April and it will take some time for field conditions to dry enough for field work and planting to begin. Farmers are encouraged to consider the following as they wait for the 2018 corn planting season to begin.

Tuesday, April 17, 2018

Nutrient Management Podcast: Spring Nitrogen Outlook 2018


Spring is upon us! While there still may be snow on the ground, on this episode we have your spring nitrogen outlook. Guests Brad Carlson, Fabian Fernandez, Dan Kaiser, Greg Klinger and Anne Struffert answer some of your most frequently asked questions, including: How much N should I apply this spring? If I applied N in the fall, how much have I lost going into spring? What about starter fertilizers? How much N should I apply as starter? Is a preplant soil N test worth it this year? Should I use a nitrification inhibitor? What should I do about anhydrous if soil is too wet?

Monday, April 16, 2018

Respirator fit testing webinar

Do you have employees who need to wear a respirator this year? Or would you like to be a fit testing resource to your community? University of Minnesota, Extension is hosting a free fit test training webinar in collaboration with 3M on April 30th. 

Image: 3M

Evaluating Your Winter Wheat and Rye Stands

As wintery weather persists, you may wonder if your winter wheat or rye has survived this winter.  If you are really anxious or bored, you can dig up some crowns across the field and cut them longitudinal (lengthwise) with a very sharp knife or a safety razor blade. If the crowns look white/yellow to light green, they are healthy and have survived the winter to date. If you find crowns that have turned tan to brown and soft, they likely did not survive this winter.  A second method to check whether seedlings are alive is by trimming the roots and leaves down to about ¼  to ½ ” above and below the crown. Place these seedlings on a wet paper towel and place the towel in a Ziploc bag or plastic container that can be sealed. Place the container at room temperature and check for regrowth in 48 hours. Viable seedlings will show regrowth almost immediately (Photo 1). 


Photo 1 - Regrowth of young winter wheat seedlings after 36 hours incubation in a Ziploc bag at room temperature (photo courtesy of Blake Vandervorst)

Unfortunately, checking a single or a few crowns does not tell the whole story as winterkill is often patchy across a field (Photo 2).  To determine whether you need a plan B for these fields requires you to wait until the field starts to green up sufficiently in order to do a reliable stand count.  The more protected areas will green up first, while bare knolls or lower lying areas where water or ice may have been present sometime during the winter and early spring will be slowest to green up.


Photo 2 – Area with partial and uneven winter kill (photo courtesy of Joel Ransom).

To do a stand count, use one of the following two methods:

1.        Count the number of plants in a foot of row at several locations in the field.  Take an average and convert in plants per acre using Table 1.

2.        Take a hula-hoop, let it fall, and count the number of plants inside the hoop.  Repeat this at random several times across the field and calculate an average.  Use Table 2 to convert the count to an approximate population per square foot or acre.


Table 1 - Average number of plants per foot of row for different row spacing and plant densities per acre.
                                                                               

Plants per acre (times 1 million)
Row Width
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5









6”
9.2
10.3
11.5
12.6
13.8
14.9
16.1
17.2
7”
10.7
12.1
13.4
14.7
16.1
17.4
18.7
20.1
10”
15.3
17.2
19.1
21.0
23.0
24.9
26.8
28.7
12”
18.4
20.7
23.0
25.3
27.5
29.8
32.1
34.4


Table 2 - Adjustment factors to multiply the number of plants inside a hoop and convert the number into the number of plants per acre.

Hoop Diameter
Multiply by


30”
8,900
32”
7,800
34”
6,900
36”
6,200
38”
5,500



Uniform stands of 17 plants per square foot or approximately 750,000 plants per acre are sufficient to keep and do not require a plan B.  Consider replanting only those areas of the field where stands are below the threshold with, for example, spring wheat.  No-till seeding HRSW into standing HRWW is possible but creates some challenges later in the season because the two crops will reach growth stages at different times and complicate not just harvest but also the timing of herbicides and fungicides.
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