Conditions have been wet and cool across many midwest states this planting season. What does this mean for your planted soybean fields?
Soybean stand loss early in the season is often due to “damping off” which is a broad term which refers to seed and seedling diseases. The four big ones are pythium, phytophthora, fusarium and rhizoctonia. Pythophthora and pythium are often the two most common and troubling for us in our market area. These two pathogens are sometimes also referred to in slang as “water molds” as they thrive in saturated soils with free water. They have spores that can survive in soil and crop residue for long periods of time and when soils become saturated with free water spores can detect plant root exudates. They then literally swim to the root and infect. Quite simply, without wet soils they are not able to readily infect, so in drier years they are typically not an issue.
Stand loss early in the season with early-to-normal planting dates is more typically associated with pythium because it thrives in cold wet soils; while phytophthora infects more readily in somewhat warmer wet soils. With the recent cooler weather, pythium may be the leading candidate as the pathogen causing any stand loss/damping off within fields but an actual lab diagnosis can often be the only way to 100% confirm the pathogen in question as all four of the major soybean damping off diseases can be hard to distinguish from one another with the naked eye and their infection environments can overlap each other.
Many soybean varieties offer native genetic resistance to specific races of phytophthora which is very valuable. However, there are many different races of phytophthora present even within the same field, so one specific phytophthora gene may not always be effective. Partial resistance or “field tolerance” is also a rating which you will see in most product guides which is just as important. The fungicidal components of virtually all complete soybean seed treatment packages also offers a level of protection against the damping off pathogens. However, that protection can simply be overwhelmed under high pressure saturated soil conditions and begins to slowly fade following the first few weeks after planting.
Use of Pre-Emerge Herbicides
Soybean seedlings may also be further stressed when PPO soybean pre-emerge herbicides containing flumioxazin, sulfentrazone, or saflufenacil have been used in conjunction with cool and wet soil conditions. Soybean pre-emerge herbicides containing these actives are quite common in the industry and used on lots of soybean acres as they are generally good at controlling problematic small seeded broadleaves such as marestail and waterhemp. These herbicides can cause some stunting of seedlings most often due to some minor to moderate burning of the cotyledons and hypocotyl as the seedling emerges through the soil/herbicide layer. Cool wet conditions make it harder for the young seedling to metabolize the chemical.
It is quite possible that any fields currently showing damping off symptoms may have more than one thing going on. Variety, pathogen and herbicide may all play a part.
Contact your local Hoegemeyer DSM or Agronomist for more information.
Every year, when the calendar gets close to June, the question of whether to back off on relative maturity or not arises at least somewhere in the Hoegemeyer footprint. Some areas this spring have been continually hit with significant rain events that have not allowed corn planting to progress. No matter what date you planted your corn, it still takes about 125 growing degree units (GDU’s) for corn to emerge. In addition, research has shown that full season corn hybrids can also adapt to GDU’s needed for growth and maturity when planted later. For example, a corn hybrid will adjust to late planting by reducing the GDU’s necessary to reach black layer by about 6 units per day. An example would be a hybrid planted on May 20th that would require about 150 fewer GDU’s than the same hybrid planted on April 25th. Although the time required for a late planted hybrid to go from silk to black layer is increased, the time period from planting to flowering (tassel) is actually significantly reduced. Although later corn planting dates are not beneficial overall in terms of yield response, later planting dates will help accelerate emergence out of the ground and the plant will benefit from more measurable GDU’s per day after emergence compared to significantly earlier dates.
There is a point when backing up in maturity does make sense, especially as one moves north. In general, the best chance to approach optimum yield vs. planting date is still achieved by sticking with the normal adapted corn maturity for that area until the last week of May. After that, reducing maturity by about 5 days is justified as we approach June 1st. As we enter the 2nd week of June, reducing maturity by another 5 days is justified. Beyond the 2nd week of June, planting corn is usually not advised. Note that these estimates vary some depending on the individual situation and geography. If we were able to predict a cooler than normal grain filling period (August and early September), then one might error on the side of caution and plant an earlier hybrid the closer we get to June.
Questions regarding corn replant? Several factors come into play but as the calendar moves into the 1st week of June, more times than not, the best choice is to leave your remaining stand. Table 2 from Iowa State University gives estimated yield potential for corn at different final plant populations and planting dates.
Heavy, persistent rains have also delayed soybean planting for several areas of the Hoegemeyer footprint. Take a look at this article from UNL extension in regards to delayed soybean planting decisions and practices. http://cropwatch.unl.edu/delayed-planting-in-soybeans This article uses June 15 as a potential date to consider a 1/2 maturity group reduction (example would be reducing from a 3.5 RM to a 3.0 RM). However, we feel June 20 is a more relevant date for locations south of Interstate 80. As one moves north of Highway 20 in Nebraska and Iowa, June 1st can be used as a potential date for a ½ maturity group reduction (example would be reducing from a 2.5 RM to a 2.0 RM). Past situations would show that fuller season soybeans give the best chance for yield, especially as we move south, for several reasons:
1. Late planted full-season soybeans south of I-80 are not at the same risk of a fall freeze as those planted further north.
2. For the most part, short season soybeans do not move south well. Soybeans are triggered to go into reproductive mode based off daylight. They are more sensitive to photoperiod than corn. There is typically more heat as you move south, but also longer nights. Soybeans that are very early in maturity, that are planted late into a southern zone will potentially be very short and will not produce much for pods or canopy.
3. Fuller season soybeans still have the best potential to capitalize on late season rains come September and early October.
If you have specific questions about your farm, please don’t hesitate to contact someone on our Agronomy team. We are here to ensure the long-term success on your farm!
Depending on the specific geography, soybean emergence has either already taken place or soon will as soybean planting has begun to progress over the last week across much of the Hoegemeyer footprint. With some of the significant and frequent rain events along with the potential for some slightly cooler temperatures, it is possible that we may see some minor to moderate visual injury symptoms to fields that have certain pre-emerge herbicides such as the PPO inhibitors and photosynthetic inhibitors applied. Active ingredients for these herbicide groups include sulfrentrazone, saflufenacil, and metribuzin. Pre-emerge herbicides with these active ingredients have become quite popular due to the fact that they are generally quite effective at controlling troublesome small seeded broadleaf weeds that have become resistant to glyphosate (such as waterhemp and several others). Soybeans emerging under cool and wet conditions or when emergence directly coincides with a heavy rain event could be more vulnerable to injury. However, in the vast majority of cases, the visual symptoms which could include seedling stunting and cotyledon necrosis are short lived. The seedlings will typically resume normal growth once environmental conditions improve and the plant is better able to metabolize the herbicide.
ILeVO® fungicide soybean seed treatment (fluopyram) from Bayer Crop Science which was recently approved for commercialization in 2015 is very effective at protecting soybeans from both Sudden Death Syndrome (SDS) as well as Soybean Cyst Nematode (SCN). It is highly systemic into the root and crown of the seedling. Nearly 100% of all seedlings will exhibit minor to moderate visual injury symptoms on the cotyledons at emergence regardless of environmental conditions. Bayer calls this the “halo effect”. The most significant symptoms may take place in fields where ILeVO treated seed was used in conjunction with one of the pre-emerge herbicides listed above, especially under cool and wet conditions. However, once again the bark is often worse than the bite as research is showing that there is most often no impact on final stand or yield! Ironically, it is those cool and wet conditions that are also most favorable for SDS infection soon after planting.
So be aware, but not alarmed if you see what looks like some visual injury symptoms in a field of soybeans at emergence. There are multiple factors that could be playing a part. If you have any questions, be sure to contact your Hoegemeyer DSM or Agronomist.
Note: The vast majority of all Hoegemeyer soybean test plot seed was treated with Right Stand® + ILeVO® this year in order to give our products the best chance at fulfilling genetic potential.
Below are some links to resources including photos that may be useful in preparing for this potential situation.
Have you ever wished you had more information before making a decision impacting all of your acres? A growing number of farmers are using their own fields and equipment to run experiments aimed at answering their own questions. The tools that are making this possible can be the same ones that farmers are already using in the operations – GPS and yield monitors. Several state university extension programs are dedicated to helping farmers develop their own well thought-out, statistically valid experiments. Examples that I’ve seen include fertilizer rates, planting populations, row spacing, cover crops, and many new products and technologies. The information has been valuable.
If you are interested in doing your own on-farm research, there are people who can help. Here at Hoegemeyer, Agronomist Craig Langemeier, Product Managers Ryan Spurgeon and Ryan Siefken, and Precision Ag Lead Jeremy Horvatich can help you design experiments related to our hybrids, varieties, and seed treatments. Here are also some links to some university websites dedicated to on-farm research:
Hoegemeyer believes in seed treatments as a means to capture greater yield by protecting the soybean seed from the start. Whether it’s on your own acres or when going up against the competition, Right Stand® and Right Stand + ILeVO® treatment packages protect the genetic potential on every seed, every bag and every acre!
Here's a few reasons why:
Wider Planting Window
Planting in cool, wet soils may result in slower emergence.
Increased disease pressure is possible.
Seed treatments allow for earlier planting dates and reduced replant.
Tolerance to High Residue Environments
Increased soil residues can harbor pest populations and disease pathogens.
Residue is associated with cool soil temperatures which may delay emergence.
Improved Soybean Plant Performance
Pest and Disease control
2.5 bushel average yield advantage for Right Stand over no treatment.
2-10 bushel yield advantage for Right Stand + ILeVO over base package depending on severity of SDS and SCN pressure.
Right Stand and Right Stand + ILeVO soybean seed treatment is a proprietary mix of chemistries including an insecticide, biological growth stimulant, and multiple fungicides offering broad spectrum protection. A common misconception is that seed treatments are only needed for early planting dates. Some insects and diseases are not limited to cool and wet conditions associated with early planting dates. An example would be Phytophthora Root Rot which is also very active under warm and wet soil conditions.
If you have any questions about soybean seed treatments, visit your Hoegemeyer DSM, Dealer or Agronomist.
Categories:Disease, Ryan Spurgeon, SoybeansComments:0Tags:
Hoegemeyer Agronomy Team, ILeVO seed treatment, Right Stand, Ryan Spurgeon, Soybean Seed Treatment, The Right Seed