C.O.R.N. Newsletter: 2015-18
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Fungicide Options for Soybeans
I looked at the soybean prices on Sunday – all were still less than $10/Bushel. This price combined with yield losses due to late planting, extra expenses for additional late weed control, and flood injury really put the kibosh on all but the most guaranteed return on investment for the remainder of 2015. Here are a few guidelines, results from our studies in Ohio that point to the best return on investment.
Foliar pathogens have the most impact on soybeans at the later growth stages (R3 to R6) by reducing the photosynthetic area of the leaves that contribute to pod development and seed growth (http://www.oardc.osu.edu/soyrust/2007edition/10-SoybeanGrowthandDevelopment.pdf). Soybeans also have an uncanny ability to compensate for missing neighbors. The profitability measure for the 2015 season will be to scout for the occurrence of diseases after flowering R3 and choose the best fungicide if necessary.
1. Septoria brown spot. This is a lower canopy disease, which surprisingly, we have not been getting too many reports of this year. Where we are, it is from fields that are planted into continuous soybean and have heavy residue. Even in these situations, the yield loss for this is still on average 2 to 3 bu/A.
2.
Frogeye leaf spot. This disease we are monitoring, not only because there are a few highly susceptible varieties but also because there are reports from Illinois, Indiana, and up and down the Mississippi of populations that are no longer managed by the strobilurin class of fungicides. If you see it, please send this to the lab ASAP, so we can run some tests. We have seen yield differences with low levels of disease (5 to 12% leaf area affected) of 5 to 10 bu/Acre. This is the one to keep an eye out for but the timing for sprays is between R3 and early R4.3. Sclerotinia stem rot or white mold. For those fields with a long history of this disease, this can cause problems when we have cool nights (a.k.a no air conditioning turned on in your house) and heavy dews. We have started our scouting for this pathogen as fields begin to get closer to flowering. However, for those historic areas where white mold is always present AND a susceptible to moderately susceptible variety was planted, a fungicide may be necessary this year. The key is the timing, and coverage of the fungicide in the field. The target area is the lower part of the stem.
a. Approach – we have measured significant reductions in white mold when we applied this fungicide at Western branch right before flowering followed by a second application 10 days later.
b. Endura – we have measured significant reductions in white mold with this fungicide with one application timing (R1 – a few plants are beginning to flower in the field).
c. Phoenix and Cadet Herbicides – both have reduced the incidence of white mold in trials in northeast Ohio. If you are also going after weed escapes, this may also be a tool to consider.
d. Topsin M – this has been the stand by white mold fungicide, but for the past 3 years, we have not been able to measure reductions in disease.
e. Some cautions, we have not been able to reduce white mold with a fungicide nor with a herbicide if the field is planted to a highly susceptible variety and the crop is in full flower and infections have already occurred. These materials mainly work as protectants and have to be on the plant at those lower nodes to protect it prior to the arrival of the pathogen.
In summary, for foliar pathogens there is time to let the plants recover and take a look later in the growing season to determine if the pathogens are present. This is the year to focus those scouting efforts on highly susceptible varieties. For historic white mold areas, this will be another year to implement measures on those highly to moderately susceptible varieties. -
Wet Weather and Weed Management
1. Wet weather has delayed POST herbicide applications in both corn and soybeans. This can result in weeds and crops that are larger and more advanced in growth stage than anticipated. The larger crop is primarily a problem in corn, where a more advanced growth stage can start to limit herbicide options. Be sure to check labels and the OH/IN/IL Weed Control Guide for information on maximum crop size and stage for herbicides (Table 8 on page 68 of 2015 edition). Larger weeds may require higher rates or more complex POST herbicide mixtures. Glyphosate and Liberty rates can be increased in Roundup Ready and LibertyLink crops, respectively. Glyphosate usually does not need much help to control large grasses, but the addition of a clethodim product or Fusion to Liberty in LibertyLink soybeans will be required for grasses more than a few inches tall (and always for control of barnyardgrass, yellow foxtail, and crabgrass). Maximum rates of glyphosate can be required for control of large giant ragweed, especially if they have developed some resistance. The addition of fomesafen or Cobra can improve control of glyphosate-resistant giant ragweed populations, and crop oil should be included where these herbicides are used. Various herbicides can be mixed with glyphosate in corn to improve giant ragweed control, including Status, Impact/Armezon, Callisto, Laudis, etc. Increasing spray volume can improve penetration of herbicide into a taller, denser weed and crop canopy, especially for contact herbicides.
2. Consider altering the weed management strategy in fields with late-planted soybeans. While we advocate strongly for the use of residual herbicides in soybeans, the need for full rates of residual premix products applied in late June is debatable. Two issues here: a) some residual herbicide labels specify 10 month or greater interval between application and corn planting next year; and b) we are through the period of peak weed emergence, so that the residual herbicide activity does not have to last as long (assuming that POST herbicides will be applied). In addition, soybeans grow more rapidly when planted in late June compared with early May, so there is less time until a crop canopy develops to help with weed control. Where residual herbicides will be applied, check labels and the Weed Control Guide for information on re-crop intervals to corn or other crops, and consider switching to a less persistent herbicide with shorter re-crop restrictions where appropriate. It’s probably also possible to forgo the residual herbicides in some fields with low weed pressure, and just use POST herbicides. Be aware however that Marestail can emerge into July, and relying on POST herbicides for control of this weed is not a good idea unless Liberty can be used.
3. Can I plant soybeans in fields where corn has failed when I have used pre-emergence herbicide X, Y. and/or Z? There’s a very straightforward answer to this question, and then a more complicated answer with less certainty requiring some knowledge not found on herbicide labels. Labels for corn herbicides provide re-crop intervals that should occur between application of corn herbicides and soybean planting next year, and these typically range from 6 to 10 months for any residual corn herbicides that are not also used in soybeans. Based on this, it’s not possible to plant soybeans anytime the same season where an atrazine premix has been used, and also Lexar/Lumax, Acuron, Halex GT, Balance, Corvus, or SureStart/Tripleflex among others. The grass herbicide components (metolachlor, acetochlor, dimethenamid, pyroxasulfone) of these products are not the problem since they are used in soybeans anyway. It’s the atrazine, mesotrione, isoxaflutole, and clopyralid components that result in re-crop intervals of 6 months or more. One of the options here always is to plant a preliminary test strip of soybeans in a field, and see how it looks after a few weeks, before planting the entire field (i.e. field bioassay). This approach can be impractical this late in the season, when planting as soon as possible can maximize soybean yield potential. Aside from this, we usually advise contacting a manufacturer representative directly or through a dealer to get their assessment of the situation. There may not be a concrete answer provided, but this can result in some information along the lines of “we think there is a good shot the soybeans might make it” or “absolutely do not do it”. The only one of these herbicides that we can provide any advice on really with regard to soybean planting the same season is atrazine, since it’s been around so long and subject to almost every situation possible. It is possible to sample soil and have it tested for atrazine levels, and the resulting numbers can provide some guidance on replanting (page 12 of the current Weed Control Guide). Beyond this, our experience based on feedback from growers and advisors over the past couple decades is that when 6 to 8 weeks and a lot of rainfall has occurred since atrazine application, there is a reasonably good chance that soybeans can survive and grow. However, this doesn’t mean there won’t be injury or reduced yield potential, and there isn’t any way to know really without a field bioassay and/or the lab analysis of soil.
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Saving Soybean Seed for Next Year
Due to wet weather, a few farmers in northwest Ohio have not yet planted soybean. Can this soybean seed be saved and planted next year?
1.) Check with your seed dealer. Your seed dealer may have options available to return seed. Check with your seed dealer to see what your options are.
2.) Store seed in a climate and humidity controlled environment. High temperature and relative humidity increases the rate of seed deterioration. Iowa State University researchers found when soybean seed was stored in a non-climate controlled warehouse (temperature ranging 18-82°F and relative humidity ranging 37-74%), the seed did not maintain adequate quality. Seed that was put into controlled cold storage (50-52°F and 53-67% relative humidity) or warm storage (77-79°F and 20-42% relative humidity) resulted in seed that could be safely held for the next season’s planting.
3.) Test seed quality before planting. If seed is to be saved for next year’s planting, make sure to test the seed quality before planting. At minimum, the warm germination test is needed to adjust seeding rate. (The warm germination test is used to determine under optimum conditions the percentage of seed able to germinate in a given lot.) Other indicators of quality include the cold germination test (stress test which simulates cold, wet conditions as an indicator of seed vigor) and the accelerated aging test (relative vigor level of the seed). All three tests are available through the Ohio Seed Improvement Association (http://ohseed1.org/).
Reference: Mbofung, G.C.Y., A.S. Goggi, L.F.S. Leandro, and R.E. Mullen. 2013. Effects of storage temperature and relative humidity on viability and vigor of treated soybean seeds. Crop Sci. 53:1086-1095.
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Be Patient with Wet Hay Fields
I know many hay producers reading this article are frustrated by the rainy weather. They know that forage quality is declining with each day that goes by (and why did I have to state the obvious, right?). However, I want to urge hay producers to change their focus and be patient, to make sure their hayfields are dry enough to support their equipment before they try to get out on them once the sun starts to shine again.
The loss of quality in one cutting, even the complete loss of the value of one cutting, is less than ruining a forage stand for the remainder of its productive life by running equipment on ground that is still too soft, especially if it is a younger stand. So do what is really easy for me to say, but super hard to practice right now – just be patient. Take the long look and wait until the field is dry enough to support the equipment without damaging the forage stand.
There is potentially a silver lining for those of you who have overgrown hay fields that were saturated before you could harvest them. That is this: Flooding damage is usually much more severe in newly harvested stands than in stands with full growth present during periods of soil saturation.
Research conducted in Wooster, OH by Dr. Al Barta a number of years ago demonstrated that alfalfa damage was most severe when the alfalfa had been harvested right before a flooding event. In contrast, flooding damage was much less severe in alfalfa that was full grown, in flower stage, and had not been cut prior to the flooding event. So place your focus on that and watch how over-ripe fields recover compared with fields that were cut right all the saturated soil conditions developed. This is probably good news for some of you, but bad news for others who did get their hay cut before all the rain. But whatever the case, let’s keep hoping that we will all soon be making hay while the sun shines!
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Grain Bin Rescue – Silos and Bins Loom as Death Traps on American Farms
How many of you have ever watched the ABC television show, “In an Instant?” The episodethat aired on Saturday night, April 4, 2015 and is one that hits close to our communities. As a county Extension Educator, Farm Safety is one of the most important topics our community can benefit from being educated about. The “In an Instant” show was a reenactment of Arick Baker’s grain bin entrapment. He is from New Providence, Iowa, and the accident happened in June 2013. He was totally buried under several feet of corn for approximately 3 hours. He was using a PVC pipe to try to break up some crusty corn inside a large bin when he was sucked down completely to the discharge hole of the bin. He, his mom and his father, and rescue workers reenacted the day so accurately that it was almost like the actual day of the accident.
Interspersed with the terror of the reenactment were interludes of a few minutes where the people involved explained exactly how they felt that day. I can’t imagine anyone in agriculture being able to watch the show without becoming emotionally involved. This program was one of the most incredible that I have ever watched. Arick’s mom had no trouble replicating the terror she felt that day while waiting for the rescue workers to find her son. She drove her car to the bin site at 125 mph. When she tried to call her daughter, she couldn’t event complete a sentence. The show was especially emotional for me because I can remember as a child heading out to the machine shed with my siblings and playing in the back of a hopper wagon full of corn, soybeans or wheat, without my parents or grandparents knowing. Back in the 1980’s the grain wagons weren’t the size they are now, and it was fun to pretend were digging for a buried treasure. At that time as young as we were, my brother and I had no idea how dangerous this could be – that is -- until my father found out. Once dad explained the dangers, we were done playing in the hopper wagons.
As I started at the Extension Office late in 2013, Farm Safety has been one of my highest priorities. Since 1978, Purdue University has been documenting agricultural confined space incidents throughout the United States. Approximately 1500 cases have been documented and entered into Purdue’s Agriculture Confined Spaces Incident Database (PACSID), with the earliest case dating back to 1964. Today, too many times, victims of grain entrapment are working in much fuller bins, and things go south so quickly that they’re pulled beneath the pile and suffocated literally within seconds.
Bin entrapments often end in utter tragedy: death of a father, sibling, other family member, or employee – maybe someone you ate dinner with every day or the last person to tell you “good night” each evening. Now those “good nights” are gone forever. National statistics show that farming is one of the most dangerous occupations in America. Over the past 50 years, more than 900 cases of grain engulfment have been reported, and the fatality rate is 62%. With a 10-inch auger, it take just 25 seconds for a 6-foot person to be completely buried in grain.
This Friday evening, June 26, 2015, starting at 6:30 PM will be a live reenactment by the local Fire Departments and OSU Extension for farmers, families, community members, grain elevator employees or anyone with interest in farm safety and grain bins. The best news is you don’t have to be from Paulding County to attend. The OSU Extension Office at 503 Fairground Drive, Paulding, OH, 45879, will be the site of the basic reenactment and training.
These are our communities and a free chance to be trained doesn’t come about very often. With all the rain, why not take an evening and spend with your family learning about what you can do if you were put in this situation? The Grain C.A.R.T. (Comprehensive Agricultural Rescue Trailer) is a partnership between Ohio State University Extension, the Ohio Fire Academy and agribusinesses to address Ohio’s agriculture rescue training and education opportunities. I hope we are never in this situation of a grain bin entrapment in any of the counties in Ohio, but if we are and ONE life is saved, all the training was worth it!
For additional questions, you can email questions to noggle.17@osu.edu, walk in the OSU Extension Office at 503 Fairground Drive, Paulding, OH 45879 or call (419)399-8225.
Crop Observation and Recommendation Network
C.O.R.N. Newsletter is a summary of crop observations, related information, and appropriate recommendations for Ohio crop producers and industry. C.O.R.N. Newsletter is produced by the Ohio State University Extension Agronomy Team, state specialists at The Ohio State University and the Ohio Agricultural Research and Development Center (OARDC). C.O.R.N. Newsletter questions are directed to Extension and OARDC state specialists and associates at Ohio State.
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