What to Do if I Have White Mold in Soybean?

Midwest agronomists talk mid-September crop progress

Winfield United agronomists offer detailed look at corn and soybean issues as of September 15, 2017.

In this fifth report, Winfield United agronomists offer details on corn and soybeans as as we get closer to harvest. Concerns highlighted include early soy harvest in southern Illinois, corn maturity being challenged, a wide variety of growth stages and moisture content exists everywhere; some corn being harvested early due to weak stalks, and much more.

The agronomists believe yields will be challenged by a variety of issues: early season wet conditions in some states that has led to crop progress inconsistency; compromised stalk quality due to diseases and insects; some soybeans are challenged by a wide variety of diseases and insects, especially in the northern Corn Belt; a relatively cool August will delay harvest several weeks, making early frost a concern in the northern Corn Belt, as are diseases like white mold, SDS and brown stem rot in soybeans.

Current scouting is still needed to determine pest issues, crop quality, harvest order and more. Other tips:

·         Scout crops to determine weak stalks, pest issues, harvest order. Don’t use seed maturity as the sole basis for harvest decisions. Pull back husks to look for ear rots, including diplodia and fusarium. These fields should be harvested first and dried down quickly.

·         Don’t let slow corn drydown cause you to wait too long to get into fields, leading to greater chance for standability issues and yield loss.

·         Examine vulnerable fields more closely by splitting stalks to look for crown or stalk rots that could cause standability issues and potential yield loss at harvest.

·         Scout soybeans for white mold to prepare plan for 2018. Knowing location and severity of white mold will help make better decisions in future years

·         Examine summer satellite imagery. Fields with a large gradient of biomass or loss of biomass require attention and should be inspected in person. Imagery from a tool like the R7 Field Forecasting Tool, paired with a combine’s yield monitor, can help farmers make informed harvest decisions.

·         In dry areas, soybeans may be bursting out of pods and farmers should keep an eye on fields to help determine harvest order.

·         Don’t be afraid to harvest corn before it’s dry due to potentially compromised standability. With the possible late harvest, it may be better to pick wet corn and get the yield that’s out there.

·         Take the next month to determine a postharvest plan, keeping in mind soil sampling and crop rotation, as well as hybrid and variety selection. Make plans for 2018 while lessons learned this year are top of mind.

·         As harvest approaches, prepare a plan to determine which fields should be soil sampled when crops are out of the field.

·         After harvest, if there is still time, fields should be scouted for biennial weeds. If needed, a herbicide application can be made to help prevent weed infestations next spring.

 

Read on for more details from agronomists in Illinois, Indiana, Iowa, Michigan, Minnesota, Ohio, South Dakota and Wisconsin.

 

Illinois – reported September 12

Farmers in Illinois are gearing up for harvest, says WinField United agronomist Sara Smelser. Grain moisture across the state is ranging between 18 and 32 percent, with soybeans in the R6 to R7 growth stage. Harvest began as early as Labor Day weekend in southern Illinois where early maturing soybeans were planted. Recent cool weather has slowed corn maturity, potentially delaying harvest a few weeks from what was initially expected, but on par with the 10-year average.

USDA reports indicate that 54% of corn and 58% of soybeans in the state are in good to excellent condition as of early September. Smelser says farmers have been scouting fields to assess crop progress and plant health. The R7 Field Monitoring Tool by WinField United has helped some farmers determine which fields are drying faster to target moisture testing. Farmers have also been using yield potential maps to identify fields that may be prone to weaker stalks. Smelser says those vulnerable fields should be examined more closely by splitting stalks to look for crown or stalk rots that could cause standability issues and potential yield loss at harvest.

Smelser also recommends scouting for soybean white mold as harvest approaches. This is particularly important for farmers in the northern part of the state. If white mold is found, there are several management practices that can be implemented to help reduce pressure in 2018. Rotating crops, using wider row spacing to allow for more aeration, plowing no-till fields and choosing soybean varieties with higher tolerance to white mold can help limit infections next season.

 

Indiana -- reported September 7

Glenn Longabaugh, WinField United agronomist, is seeing corn at various growth stages around the state. The early April planted corn has moisture levels ranging from 17 to 20 percent. In some areas, it’s already being harvested due to weak stalks. Wet conditions earlier in the season led to pathogens setting up shop in corn plants, so farmers should keep an eye out for compromised stalks. As soon as stalks fail, deer, birds and insects will start feeding on the grain and the potential for disease pressure skyrockets.

Longabaugh says the only thing worse than selling $3.50 corn is selling $3.50 corn that’s on the ground. He encourages farmers to conduct push tests to determine harvest order. If there are weak stalks in your rows, harvest sooner rather than later. Grain drying is expensive, but it’s a better scenario than losing it.

Some soybeans in Indiana are being harvested from premature senescence. Due to a cornucopia of pest and disease pressures, such as sudden death syndrome, charcoal rot, stem canker and brown stem rot, a full-blown harvest is expected later in September. At the WinField United Answer Plot location in Jasper, Indiana, nearly every soybean plant is infested with a pest called Dectes stem borer.

In addition to doing a push test and scouting to determine disease and insect pressure, ag technology tools can help determine harvest order with ease. Longabaugh recommends that farmers look back at their summer satellite imagery. Fields with a large gradient of biomass or loss of biomass require attention and should be inspected in person. Imagery from a tool like the R7 Field Forecasting Tool, paired with a combine’s yield monitor, can help farmers make informed harvest decisions.

 

Iowa – reported September 12

Wide variability in planting dates and environmental conditions throughout the growing season have left Iowa crop progress inconsistent across the state. On average, soybeans are at the R5 to R6 stage, and WinField United agronomist Tyler Steinkamp expects soybean harvest could begin by the last week of September. He says cool temperatures have slowed corn maturation in parts of the state. Northern Iowa is about 100 to 150 heat units behind average for this time of year, and the threat of an early frost is a concern. Areas south of Interstate 80 have been warmer and drier, so corn in those areas is maturing on-track with normal averages.

USDA reports indicate that 62% of corn and 61% of soybeans in the state are in good to excellent condition as of early September. Steinkamp says these ratings can be misleading because of the variability in conditions across the state. Some parts of Iowa, including Des Moines and areas further south, have not had much rain and crops aren’t looking as good as in other parts of the state. Overall, Steinkamp predicts corn yields could be down this year compared to where they’ve been in recent years.

Soybeans are looking good overall, especially in areas that received timely August rain as pods began filling. In dry areas, Steinkamp says beans may be bursting out of pods and farmers should keep an eye on fields to help determine harvest order. Soybean sudden death syndrome pressure was low this year, but some areas have been hit with white mold. Parts of eastern Iowa saw soybean top dieback, which is caused by a rare fungal pathogen that can limit yield.

Steinkamp says the best thing farmers can do is scout fields before harvest to see which fields may be impacted by weather or agronomic stress. He recommends not using seed maturity as the sole basis for harvest decisions. Walking fields to look for dead plants and weak stalks is a better way to prioritize harvest timing. Farmers should also pull back husks to look for ear rots, including diplodia and fusarium. These fields should be harvested first and dried down quickly.

Steinkamp cautions that slow corn drydown may cause farmers to wait too long to get into fields, leading to greater chance for standability issues and yield loss. He says technology like WinField United R7 archive maps can help target areas that may be a higher priority for harvest, but the only way you can really make informed harvest decisions is to scout fields.

 

Michigan – reported September 11

Corn growth stages currently range from milk to dough, and an early frost is a concern with these plants, says Ken Shemka, certified crop adviser with WinField United. Farmers need 30 to 60 days without a frost in several areas. Corn plant maturity is a little behind what it was last year. On the other hand, corn silage should be mature by September 20.

Soybeans are about two to four weeks from being harvested, depending on where rainfall was received over the past one to two months. On the east side of the Thumb of Michigan, corn and soybeans are still quite green from rains received in the last month or two, but they will mature rapidly and be ready for harvest with good sunshine, Shemka notes.

Many soybean fields, particularly in the Thumb and Saginaw Valley areas, have heavy outbreaks of white mold.

Several cornfields are displaying nitrogen deficiency, with yellow midrib on the lower half of plants, and ear tips not well-filled. Abundant rainfall at the end of June, when some fields were flooded for a period of time or water moved the nitrogen below the root zone and out of reach of corn plants, is likely the reason for some of this denitrification.

Shemka stresses that a nitrogen stabilizer should be applied every year to protect the nitrogen that’s been applied and the investment made in that nitrogen. Farmers can lose up to 50 percent of nitrogen applied for crop uptake because of heavy rains and standing water in cornfields. Good soil drainage is very important for any crop growing in the Thumb and Saginaw Valley regions.

If maturing corn lacks the nutrients needed to finish filling ears and kernels, the plant could cannibalize needed nutrients, pulling them from the stalk, and thus weakening it. If high winds are present, plants could easily lodge. Remember that when a seed is planted, its mission is to produce more seeds and fruit. It doesn’t care where the nutrients come from —usually the soil if available, otherwise the plant/stalks. That will depend on environmental conditions, says Shemka.

 

Minnesota – reported September 11

Corn and soybeans in Minnesota are at a range of growth stages, according to WinField United agronomist Jon Zuk. He’s seeing corn ranging from R4 to R5, and soybeans are between R5 and R7. Corn is in good condition right now, but due to a relatively cool August, the crop won’t likely be ready for harvest until the first or second week of October. If the state experiences an early frost around that time, there’s danger to finishing that crop.

Zuk is seeing a lot of white mold in soybeans around Minnesota along with other threats including sudden death syndrome, brown stem rot and potassium deficiency. Farmers can also expect to harvest soybeans in early October. This is a little later than past years, as farmers typically get in the combine for soybeans in mid-September.

At this time in the season, many farmers are thinking ahead to harvest order. Keep it simple for soybeans and harvest when they are ready. Waiting too long will result in over-drying and seed shatter. Corn harvest order should be determined with a preharvest evaluation, such as performing a stalk integrity test, cutting open the stalk and checking for any abnormalities. Zuk says don’t be afraid to get out and pick corn before it’s dry due to potentially compromised standability. With the possible late harvest, it may be better to pick wet corn and get the yield that’s out there.

In addition to evaluating harvest order, farmers should take the next month to determine a postharvest plan, keeping in mind soil sampling and crop rotation, as well as hybrid and variety selection. Zuk recommends making plans for 2018 while lessons learned this year are top of mind.

 

Ohio – reported September 15

Corn is currently at the R5 growth stage and will soon be coming up on black layer, with soybeans between R6 and R7 and also right around the corner from maturity, says Joe Rickard, WinField United agronomist.

Compared to the beginning of the season when heavy rains hampered crop growth, corn and soybean fields look very good now, observes Rickard. Ohio farmers saw a dry August, which helped immensely in drying out waterlogged crops. Rickard believes yields should be fair to good this year. Some corn and soybean fields could start being harvested in two to three weeks, which is about right on schedule with previous years.

Determining harvest order is important, and farmers need to scout fields — ideally with the help of their retail seller or agronomist — to prioritize them for harvest, Rickard notes. Corn stalks that fall over when pushed and are soft when pinched are likely experiencing a stalk rot disease and should be harvested first. Corn plants with stalks that remain upright when pushed and are firm when pinched can be harvested later. 

While prioritizing harvest is the main concern right now, something that farmers should be aware of once they get crops out of the field is making sure they do a fall burndown herbicide application. This will be critical in controlling troublesome weeds such as marestail in the spring.

 

South Dakota – reported September 12

South Dakota farmers are gearing up for harvest, despite recent cool temperatures that have slowed crop maturity. Corn is in the dent stage, and soybeans are between R5 and R7, with many of the early maturing varieties starting to change color. The latest USDA reports indicate that 42% of corn and 48% of soybeans are in good to excellent condition across the state.

WinField United agronomist Kyle Gustafson says unseasonably cool temperatures and late-season rains have helped alleviate drought stress in some areas, which should help with grain fill and test weights. The downside of the cool temperatures is that crop maturity is delayed compared to averages for this time of year. Gustafson estimates crops are seven to 10 days behind where they were last year based on growing degree unit accumulation. While some early soybeans will be harvested in mid-September, he expects harvest could begin the last week of September, which is about a week behind normal start dates for the state.

Determining harvest order is top of mind for most farmers right now. Gustafson recommends prioritizing fields based on seed maturity, grain moisture and stalk integrity. Push or pinch tests can help determine whether stalk rots are present in corn and how severe yield loss potential could be. If stalk rots are identified, prioritize those fields for harvest to reduce lodging yield losses. Farmers should also be scouting for white mold in soybeans. Nothing can be done for white mold this season, but knowing location and severity of white mold will help farmers make better decisions in future years.

The R7 Tool by WinField United can help determine crop maturity so that farmers can get a general idea of harvest order. The in-season images provided by the tool can help identify areas in a field that might have been stressed during the growing season. Extra scouting of these areas can be done prior to harvest to determine how stress impacted crop health.

Gustafson has been noticing late-season weeds, including kochia and waterhemp, in some soybean fields. He recommends a preharvest herbicide application to maintain harvest efficiency and to avoid combine plugging in fields where weeds are an issue. As harvest approaches, he also suggests that farmers communicate with their agronomist to determine which fields should be soil sampled when crops are out of the field.

 

Wisconsin – reported September 15

Crops in northwestern Wisconsin continue to struggle, and recent cool weather has hindered the crop progress farmers were hoping for, says Tim Mares, master agronomy advisor, WinField United. Both corn and soybeans are more than two weeks behind schedule and need warm weather throughout the month of September, and perhaps even the first week of October, to mature.

Most corn is in the early dent stage, and soybeans are in the R5 to R6 growth stages, says Mares. Dairy farmers anticipate starting corn silage in about two weeks.

Corn and soybeans should yield quite well if they reach full maturity. However, some soybean fields have white mold, which could drastically reduce yield. Farmers should harvest white mold fields last and thoroughly clean their combines before harvesting corn to keep from spreading the disease.

Mares also recommends that farmers inspect their corn fields for stalk rot diseases and harvest the fields with stalk rot first, leaving healthy corn fields for the tail end of harvest.

After harvest, if there is still time, fields should be scouted for biennial weeds. If needed, a herbicide application can be made to help prevent weed infestations next spring.

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