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.
Increase the performance and profitability potential for your fields with these Hoegemeyer planting population recommendations. Our recommendations are powered by years of local testing data.
The testing – multiple testing variables for a better understanding of product performance
Hoegemeyer continues our extensive work on corn population studies. We test our current line-up along with new experimental hybrids coming down the pipeline. At each location, we plant four rows, 20 ft plots at five populations (18k, 26K, 34K, 42K, 50K) and we replicate this process three times. We will take stand counts and harvest the middle two rows come harvest time. This provides us information to help understand how these hybrids perform at different yield environments.
Each location will then be categorized into one of four different Yield Environments:
Very High equals >240 Bu/A
High equals 180-240 Bu/A
Medium equals 120-180 Bu/A
Low equals <120 Bu/A
The results – ideal plant population recommendations for your unique acres
As a result, we create these population charts for each hybrid in our line-up to help educate farmers about the ideal population for their yield environment. Use these recommendations and work with your local Hoegemeyer dealer to maximize the potential of your seed.
The team – in-house agronomy research to provide local solutions
At Hoegemeyer, we are proud of the in-house agronomy research that we provide to farmers to help educate their farming decisions. It’s just one more step in offering top-quality products coupled with expert advice that provide you that Western Corn Belt Performance you deserve on your acres.
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!
Planting is well underway in the Hoegemeyer footprint and we have corn anywhere from seven leaves or more in Oklahoma to seed that still needs to get in the ground. I have been travelling and looking at fields over the last two weeks across Nebraska, Kansas, Missouri and South Dakota. All areas have had one thing in common — an abundance of moisture. In fields where water could drain, we are seeing some excellent stands in our Hoegemeyer products. In areas where water ponded and low lying fields are the fields where we are seeing some stand issues. Also, some fields planted on Friday, April 15, and Saturday, April 16, seems to be suffering from imbibitional chilling injury. Most of the Hoegemeyer footprint received substantial rain on Sunday, April 17, causing cold and saturated soils. These cold, saturated conditions have caused plants in several fields to leaf out underground resulting in stand loss. Aside from a few stand issues, the 2016 crop just needs a little heat and sunshine, and it will be off to the races. Now is the time to be scouting your fields for stand establishment issues to make sure to set yourself up for a successful harvest. If you have any questions or issues, contact your local Hoegemeyer DSM or Agronomist.