Crops

Manage diseases with multi-faceted approach

Written by Jason Worthington on .

When considering seed treatments, we usually think first about their necessity and then what products will work for a particular field. We don’t often think about stewardship of these products. I am guilty of it as well. When discussing seed treatments, I usually talk about their benefits and product selection with a mind toward disease control. Stewardship is a second thought.  

However, when we look at available seed treatment products compared to the spectrum of seedling diseases, we quickly realize the importance of stewardship. There are few effective modes of actions available. To conserve seed treatments as a crop protection tool, they must be used in conjunction with sound cultural practices.

In this part of the world, when we think about resistance, herbicides are our first concern. But resistance management should be considered when dealing with any pest, including seedling diseases. When you break down our driver diseases and effective sites of action, the need for resistance management becomes much more apparent. There are essentially six different sites of action, or classes of fungicides, used in seed treatments today, compared to 19 classes of herbicides.

But, just as not all herbicides are effective on all weeds, not all seed treatment fungicides are effective on all seed-borne or seedling pathogens. When we look at our driver diseases used to make seed treatment decisions, they fall into two classes: water molds (phytopthora and pythium) and true fungi (rhizoctonia and fusarium). When we look at these groups separately, there are only three modes of action and four sites of action to control true fungi and a mere two sites of action effective against water molds. With so few choices coupled with logistical difficulties of handling multiple seed treatments, rotation of fungicides becomes complicated to implement as a resistance management strategy.

So what are our options? First, seed treatments cannot be our only defense against disease. Just because a fungicide is applied to the seed does not mean we can ignore other factors that favor disease development. Remember the components of the disease triangle from biology class. To have a disease, we need three things: a host, a pathogen and a favorable environment. Seed treatments attempt to address one piece—the pathogen—but additional management can take care of both the environment and the host.

We can manage the environment by waiting for soil conditions to be correct. While not always possible, this is the best line of defense against most soybean seedling diseases. The diseases of concern all have a preferred temperature range. Avoiding temperatures in the ranges outlined in the accompanying table can decrease the likelihood of infection.

Perhaps more important than disease is proper soil moisture. Planting into fields with adequate—but not excessive—moisture is ideal for numerous reasons. Not only do many fungal diseases thrive in saturated conditions, but you also want to avoid compaction, which compound saturated conditions, hamper seedling growth and contribute to disease.

We can also manage the susceptible host component of the disease triangle. Selecting varieties with resistance to soil-borne diseases such as phytopthora or sudden death syndrome is the obvious place to start, but soil conditions can also have a huge impact on the amount of time a seedling remains vulnerable to infection. Anything that limits the amount of time a seed spends underground and promotes rapid growth of a young plant lessens the time a plant remains vulnerable to infection. We see this time and again in years where SDS is common. The fields affected most severely often have seedlings that endured stressed or prolonged emergence periods. Think about how much more vulnerable an infant is to the flu than a healthy adult. Proper temperature, moisture, depth and seed placement all impact the growth and development of the soybean plant just as much as the disease.

Managing diseases takes a multi-faceted approach. Over-reliance on any one method of control—cultural or chemical—can lead to disappointing short-term results. In the long term, that reliance can lead to the development of resistant pathogens. It is important keep integrated pest management strategies at the front of our decision-making process for immediate success and continuing efficacy of our control options.

Seeing is believing

Written by MFA Agronomy Staff on .

In 2017, more than 700 MFA employees, ag industry personnel and growers toured MFA’s Training Camp test plot in Boonville, Mo. Two events were held at the research site this year: MFA’s Sixth Annual Training Camp and MFA’s Annual Grower Field Day.

These events give participants hands-on involvement in our testing and product evaluation process. Attendees viewed trials on MorCorn hybrids and MorSoy varieties, soybean seed treatments and foliar nutritionals. They heard presentations from experts on spreader calibration, Bt corn traits, evaluating dicamba symptomology in the field, and breakdown of herbicide modes of action for corn and soybeans.

Beyond the educational opportunities these field days provide, multiple replicated testing sites across MFA’s trade territory delivered vital data for product improvement and evaluation. Here are some summaries and results of these trials at the Training Camp site.

MorCorn hybrid trials

The MorCorn trials were planted April 13 with a total of 37 hybrids ranging from 95-day CRM (comparative relative maturity) to 117-day CRM. We tested 12 MorCorn commercial checks against 24 experimental hybrids and one competitor hybrid. The field was fertilized with 300 pounds of actual nitrogen in the form of SuperU. The planting population was 32,500 plants per acre.

Yields were impressive once again at our site. The top end hit 258 bushels per acre with an experimental hybrid and a MorCorn commercial hybrid. At the bottom was a MorCorn commercial hybrid and an experimental hybrid at 189 bushels per acre. Results from this year’s MorCorn Training Camp trials can be seen in Figures 1A and 1B. In addition to the Training Camp trials, these hybrids were tested across multiple environments and geographies in 11 other locations within MFA’s trade territory.

MorSoy variety trials

In terms of growing soybeans, the region MFA serves is very diverse, which shows in the diversity in the MorSoy line. Our soybean maturities range from group 3.0 to a group 5.0, and traits include RoundUp Ready 2 Yield Technology, RoundUp Ready Xtend and LibertyLink along with conventional varieties. The MorSoy trials were planted May 31 with 54 varieties, including 37 MorSoy commercial checks against 15 experimental varieties and two competitors. The planting population was 140,000 plants per acre. We had four trials to compare by relative maturity ranges: Trial 1 was 3.0-3.6, Trial 2 was 3.7-3.9, Trial 3 was 4.0-4.5 and Trial 4 was 4.5-5.0. The trials included all of the herbicide technology traits combined, so weed control was maintained with a sound agronomic conventional herbicide program.

In addition to Training Camp, these varieties were tested across multiple environments and geographies in 12 other locations within MFA’s trade territory. Results from this year’s MorSoy Training Camp trials can be seen in Figures 2A, 2B, 2C and 2D.

N stabilizers

Nitrogen stabilizers used on urea such as Agrotain, SuperU and Instinct have been evaluated at Training Camp for several years. We have found it important to continue our evaluation of these products for a couple reasons. First, several products enter the marketplace each year, and many of those make claims to limit either volatility, leaching or denitrification as effectively as the products mentioned above without any proven activity when it comes to nitrogen stabilization. Second, weather conditions vary from year to year, and the different products may perform better depending on those conditions in relation to N application timing. For example, a product like Agrotain limits urea volatization; a product like Instinct stabilizes N below ground; and a product like SuperU provides protection above and below ground.  

To evaluate nitrogen stabilizers, we tested each product on urea applied at 80 pounds of actual N per acre. This low rate was used intentionally hopefully to prevent over-application of N and provide a better chance of separation between stabilized and unprotected urea. These treatments were compared against an untreated check and against unprotected urea applied at 190 pounds of actual N per acre. The results from this year’s trials can be seen in Figure 3.

The N responses were not as great as we might expect. Much of this is likely due to the fertile nature of the testing site. However, there are some things to note from this trial. The application date of all treatments was May 12, and the field did not receive a significant rain event until 0.75 inch of precipitation on May 18. This six-day period in which the urea was on the surface unincorporated would make volatization likely. The check receiving no additional N was the only treatment statistically different from the others. Agrotain, SuperU and Source NBPT—all of which contain NBPT, the active ingredient that combats the urease enzyme and limits urea volatility—all yielded higher than products without NBPT.  

Bt traits

This year’s Training Camp sessions included an insect resistance management presentation focused on Bt traits in corn. Discussions included management of rootworm and corn borer through proper trait selection, but much of the talk addressed the effectiveness of Bt traits on ear-feeding caterpillars such as western bean cutworm and corn earworm. We evaluated four traits with Bt technology: VT DoublePro, SmartStax, PowerCore and Viptera, all claiming to control a wide range of Lepidoptera insects. To demonstrate the impact of cross-pollination from refuge corn on the expression of the Bt trait in the ear, we detasseled one row of corn for each of the listed traits. Adjacent to the detasseled corn, we planted non-Bt corn to see if cross-pollination would dilute the expression of the Bt protein in the ear as compared to the stalk. To ensure insect pressure, 20 ears were infested with “lab-raised” earworm larvae or eggs, but feeding from the natural population was also observed.

During Training Camp, we pulled ears from the trial to show participants the differences between traits and the impact that cross-pollination had on ear feeding. What was quickly noticed is that the lab-raised earworms did not survive, and Bt traits worked well against them. We also noticed no difference in feeding from the natural population whether a row with a certain trait was detasseled or not.

The biggest finding came in evaluating the Bt traits against non-traited corn. In all cases, except with the Viptera, ear feeding was equal to that of non-Bt corn. Feeding and live earworms were found in over 15 percent of the ears in the SmartStax, PowerCore and VT DoublePro hybrids. The Viptera, which contains a Bt protein in the yet-to-be-released Tricepta corn trait stack, showed 100 percent control of both wild and lab-raised earworm. These observations show us that at least a portion of earworm populations have developed Bt resistance. However, current technology is still helping us control corn borers, a more serious concern.

Dicamba PPM trial

With the introduction of the new Xtend cropping system into our trade territory, we have been researching ways to reduce the risk to MFA and our member owners. For the past three years, we have looked at potential tank contamination issues. We also realized we needed to understand how off-target movement might affect yields. We established a study to look at low-dose responses of dicamba to non-Xtend soybeans. We treated soybeans with 2, 4, 6, 8, 10, 12, 14, 16, 18 and 20 ppm dicamba solutions sprayed across V3 soybeans. While evaluating the soybean variety, we noticed that the increased damage to the soybean plant correlated to the increase in ppm concentration. However, when we harvested the soybeans, we didn’t see any yield loss associated with this study. In short, the concentration of the solution was not high enough to cause yield loss in our particular situation. We will continue this study in the future, increasing our rates to a level that will show yield loss.

Bare-ground single A.I. herbicide breakout

For the past two growing seasons, we have had a bare-ground herbicide study to show the impact of using different active ingredients (A.I.) in herbicides to control weeds in both corn and soybeans. In this trial, we worked the ground to bare soil and started with a clean seed/weed bed. Plots were then sprayed with a single-mode-of-action (MOA) herbicide for both corn and soybeans. There are 12 single MOA herbicides for corn and 14 for soybeans. The natural weed pressure was then allowed to grow. This study allowed Training Camp visitors to visualize which MOAs are actively controlling or suppressing specific weed species and determine which would be beneficial for their own area/farms. We also include a couple of plots that were sprayed with a pre-emergence herbicide containing multiple MOAs followed by a post application of a multiple MOA herbicide to show the importance of overlapping residuals.

Figure 4 shows an example of a breakdown of a given herbicide with three different modes of action. In pictures A, B and C, you can see the effect that a single mode of action has on weed population 60 days after treatment. Picture D is a herbicide containing all three MOAs 60 days after treatment. This study emphasized the importance of having multiple MOAs to protect against weeds and weed resistance.

Spreader calibration study

Every year, we test nitrogen rate and timing at Training Camp. In these studies, we are often evaluating performance based on timing of application preplant versus a V5-V8 topdress application versus a split application. Rates often have been determined by N models or common grower practices. This year, we looked at rates influenced by spread patterns of fertilizer application equipment to demonstrate the importance of proper calibration. We took a fertilizer truck properly calibrated to spread a DAP/potash blend and pan-tested it with urea. The pans used to catch the urea were set up on 10-foot intervals from the center and on the edge of the 70-foot pattern. The first pan test was done with a 400-pound rate of urea (184 pounds of actual N). We repeated the pan test with a topdress rate of 200 pounds of urea to demonstrate that calibrations change as application rates change. In this truck, the result of spreading a lighter product such as urea when calibrated for a heavier DAP/potash blend was a high center pattern at the 400-pound rate such as the first graph in Figure 5A. A less exaggerated “W” pattern was seen at the 200-pound rate, similar to the third graph.

We used the pan catch from both tests to determine the percentage of the target rate at different distances from center of the spread pattern to set up our trial. The corresponding rates and yield data are included in Figures 5B and 5C (on page 43).

From this information, we concluded that, at the 400-pound rate, 71 percent of the spread pattern resulted in over-application by as much as 32 percent, and 29 percent of the spread pattern was under-applied by as much as 32 percent. At the 200-pound rate, 43 percent of the pattern was over-applied by as much as 100 percent of the target rate, while 57 percent of the pattern was under-applied by as much as 50 percent of the spread rate.

Though the only statistical difference in yield came between the untreated and the remaining checks at both timings, the importance of a properly calibrated spreader can be seen in nitrogen-use efficiency by limiting over-application across the pattern. In a year where N responses are higher, we can assume the under-application penalty would be much greater.

Doing our due diligence with dicamba decisions

Written by Dr. Jason Weirich on .

By now, you have likely heard that MFA Incorporated will have new internal policies for the sale and use of dicamba herbicides for the 2018 growing season. Our guidelines will be responsive to actual growing conditions based on field reports from our agronomists, crop scouts and other MFA personnel across our trade territory.

Once soybeans hit the R1 growth stage, MFA will no longer spray dicamba due to the inherent risk of off-target movement. We feel like it’s important to base our decisions on actual growth stages, and R1 is at the beginning of flowering. If we wait until too late in the season, we’re afraid that we will put too many soybeans in our territory at risk.

The Missouri Department of Agriculture has mandated that the cutoff date will be June 1 for 10 counties in the Bootheel and July 15 statewide, and MFA will adhere to those rules. But because MFA’s policies are based on plant maturity rather than calendar dates, our policy could be more restrictive than state guidelines. In other words, we may stop spraying well before those dates if conditions dictate.

To determine when to halt dicamba applications, MFA will launch an intensive scouting protocol this spring to track soybean growth and provide timely information to applicators about crop progress. We are establishing a network of “sentinel plots,” representing the average planting dates and maturity ranges of soybeans in different regions of MFA’s service territory. These plots will be scouted every Monday and reports sent to all MFA employees on Tuesday mornings with notes about maturity and potential cutoff dates for spraying dicamba. Applicators will be alerted when the majority of soybeans in their area have reached the reproductive stage, when dicamba injury can do the most harm to non-target plants.

As part of these guidelines, MFA Incorporated will only use the new dicamba formulations authorized for use with dicamba-tolerant crops, including Monsanto’s XtendiMax, BASF’s Engenia and DuPont’s FeXapan. We will not custom-apply or sell over the counter any old formulation of straight dicamba products such as Banvel, Clarity and Detonate. This does not include blended products such as Range Star, DiFlexx and Status.

Most growers are well aware that these actions are in response to widespread complaints that dicamba herbicides drifted and harmed non-tolerant crops during the 2017 growing season. Nationwide, 3.6 million acres of soybeans suffered harm associated with dicamba, and states launched 2,708 investigations into dicamba-related crop damage, according to data compiled by the University of Missouri. Missouri received about 310 complaints from growers related to dicamba, second only to the nearly 1,000 filed in Arkansas.

Arkansas has effectively banned dicamba’s use by setting April 15 as the cutoff for applications. We’re still waiting to hear if other neighboring states in MFA geography, such as Iowa and Kansas, set dates that fall outside our own guidelines. Otherwise, we will follow MFA’s policies in those areas.

In Missouri, the Department of Agriculture requires anyone spraying dicamba to have a certified private applicator license or certified commercial applicator license, the latter of which applies to MFA employees. Before purchase or use of the product, both private and commercial applicators must complete mandatory dicamba training provided by the University of Missouri Extension. We are working with MU’s Dr. Kevin Bradley to make sure MFA applicators receive this training.

We need dicamba technology to combat weed resistance, but we have to be good stewards. Protecting the technology for the future is important, not only from an economic standpoint but also an environmental standpoint. This technology is up for renewal by the EPA in December 2018, and if we have another outcome like we did last year, we may not have this tool anymore.

We hope MFA’s proactive move will set a trend so that other companies, applicators and farmers will follow our lead to help protect this technology.

We will be posting the latest information on mfa-inc.com/news throughout the growing season.

Do you know what’s in your crop insurance policy?

Written by Mike Smith on .

How do you determine what type of crop insurance best fits your operation? This might be the single most important farming decision you make in the coming years.

As we approach a new Farm Bill, many discussions are focused on where the crop insurance program is headed. Even the slightest changes can affect the inner workings of your coverage. This is even more of a reason to stay educated about your crop insurance.

The crop insurance portion of the 2018 Farm Bill benefits all Americans. Crop insurance is an important part of maintaining the most affordable and safest food supply, not only in U.S., but also in the world.

MFA Incorporated and its affiliates touch as many or more farmers in our territory than any organization in the state. This aligns us to help more of those farmers than anyone. We are providing educational opportunities for producers while helping provide current and long-term risk management strategies. Knowing more about the different types, levels and options of crop insurance helps our farmers make solid decisions on their marketing as well as risk management.

Many of the farmers we speak to only know that they have some type of crop insurance. The details often elude them. At MFA, we intend to put the knowledge back in the farmer’s hands. Understanding how a crop and its fields are broken down, either by section or by county, can make all the difference between financial disaster or profitability in a single year.

Whether it is to sample soil, advise on seed selection or make fertilizer recommendations, MFA personnel visit farms on a regular basis. We know the farmer’s operation very well. We can help find what determines profitability, breaking even or farming at a loss.

One of the most important aspects of crop insurance is revenue protection. This may be the most misunderstood coverage. Without it, drastic changes in commodity prices could devastate a farmer’s profit margins during the growing season. Locking in a profit, even before planting, is vital. This can be done with proper crop insurance strategy. Sometimes one of the most difficult things is to convince a farmer to sell crops before they are harvested, but capturing the highs in the markets during the growing season can be the difference between being profitable and operating at a loss.

Apples to apples, crop insurance is the same coverage and cost no matter what company or agent you are using. The biggest difference is the type of service they provide. Do you have to stop what you are doing to drive to a crop insurance office, or does that agent come to you? Do you get a personal review each year of your coverage and farming operation? Do the company adjusters make it easy to meet with you? These are all areas that you should consider. Expect the service that you are paying for.

If you haven’t been provided the opportunity to have a thorough examination of your operation and how crop insurance fits your needs, 2018 is an important time to do this. MFA has 38 licensed crop insurance agents. A licensed agent is available in all of our trade territories.

Important crop insurance dates

March 15 (or Feb. 28 in some of the southern areas) Spring crops final sign-up date. This is also the date to be able to make changes to your coverage and transfer your policy.

April 29
Production report deadline for 2017 spring planted production. We advise this be done prior to the sales closing date to ensure an accurate quote for your 2018 crop insurance.

July 15
Acreage reporting date. This is to report where and how many acres of spring crops were planted. We understand that making decisions on what to plant and where to plant it can be difficult. Make sure you have those conversations with your crop insurance agent. You don’t want to find out after the fact that making changes to your planting leaves you uninsured or under insured on those fields.

There are also numerous dates that differ from county to county for earliest, final and late planting dates. Be sure to check with your agent on these guidelines.

Get the lowdown on herbicide breakdown

Written by Dr. Jason Weirich on .

Now that you are likely done with harvesting, take a moment to reflect on your fields from this past growing season. When you were spending countless hours in the combine, did you notice areas that had better weed control than other parts of the field? Did you have fields with better weed control than others, yet you had the same weed control program across all of them? This is a common theme. While I would like to tell you that every field will respond the same or that each program will work every time, that’s just not the case.  

Herbicides break down in many ways. Microbes, water and sunlight are the main environmental factors that influence herbicide breakdown. Each herbicide family—and sometimes products within the family—respond differently to each process.  

Microbial degradation is the dominant factor that breaks down herbicides. Certain bacteria, fungi and algae use herbicides as a food source. Microbes are herbicide-specific, and populations are dependent on the rate of the herbicide application. Repeated use of the same herbicide year after year can cause more rapid degradation of the specific herbicide, resulting in shorter efficacy windows from that herbicide.  

Several factors can influence this process, such as soil composition, soil pH and climatic conditions. Soil organic matter influences microbial activity and provides habitat for the microbes to exist. When we look at pH, each microbe favors a certain level, but we see very little microbial activity in the extremes.

We all remember the drought of 2012 and concerns about herbicide carryover into the 2013 growing season. Length of herbicide activity is very dependent on soil temperature, soil moisture and rainfall, just to name a few influential conditions. You’re likely aware that microbes are not very active when soil temps drop below 50 degrees. That’s why a lot of fall-applied herbicides provide weed control well into spring. Very little herbicide breakdown occurs in the fall and winter from microbial degradation.

Water also has a negative effect on herbicide activity. Areas where water pools on the field and low spots are typically the first areas to break down herbicides when we have moisture or excess moisture. This chemical breakdown is a process called hydrolysis.  

Finally, sunlight is a factor in breaking down herbicides, but this photosynthetic decomposition is not as prevalent as it was 20 to 30 years ago. You probably remember having yellow-stained boots, pants, shirts and hands. The Treflan and Prowls of the world would break down relatively fast by light. That’s why I remember, as a kid, following the sprayer with the field cultivator to incorporate Treflan into the soil.   

These factors emphasize why we have to continue overlapping residuals. I can’t predict how long these residuals will provide weed control because it varies from year to year and field to field. This past year, depending on rain, the two-pass weed control program was the cleanest.  

I hope you will take time to evaluate this past year’s successes and failures to make weed-control plans for the upcoming year. These insights will provide us with some of the knowledge we need to make proper recommendations. If you have questions or want to develop a weed-control program, contact your nearest MFA or AGChoice location.

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