Managing White Mold in 2010

The 2009 season had record cool weather in July that was ideal for soybean white mold development. This disease was widespread in the north central region of the country.


In fields that had heavy white mold in 2009, no-till is the best tillage option. Tilling these fields with bury the sclerotia in the soil which increase the survival rate of the white mold fungus. The sclerotia can survive in the soil for up to seven years. Sclerotia within the top two inches of the soil surface will germinate and produce spores even in the corn. Getting as many of these sclerotia to germinate in corn so they are not able to colonize the soybean crop in 2011 is a critical step in managing this disease for future years.

Crop rotation is also critical. Fields with heavy pressure in 2009 should not be planted to soybean in 2010. The risk of an infection of white mold is too high to plant beans on beans in 2010.


Variety selection is the best tool we have to reduce the incidence of white mold problems. There are drastic differences in tolerance to white mold in varieties, but all beans are susceptible under very high pressures like we saw in 2009. Row spacing and population are two cultural practices than can easily be managed to control the canopy density and reduce the risk of white mold.

Chemical controls include soil applied Contans before the crop is planted. This biological control agent breaks down the sclerotia in the soil so they cannot germinate. There are also several fungicides now labeled for suppression of white mold, but timing is critical with application of these products. Another chemical option is the use Cobra herbicide to improve the plants natural defense against white mold. With any chemical control agent it is important to read and follow label directions.

Talk to you Trelay DSM on the best control options and soybean varieties for your farm in 2010

Vertical Tillage

Vertical tillage is newer trend that is getting a lot of attention. There are many manufactures building equipment designed for vertical tillage. Most of these tend to look like a disk in that they have a series of blades in a gang on a tool bar. Some models have individual blades mounted on spring shanks similar to a filed cultivator.

The big difference is that the blades on this type of tillage equipment are a straight or fluted blade, more like a coulter. It runs 2 to 3 inches deep and is designed to cut crop residue and not move soil like the offset or tandem disks.

Leaving the residue on top off or mixed in the top few inches of the soil helps speed up decomposition and speeds the cycling of nutrients when compared to conventional tillage systems.

The main objective of using vertical tillage is to break up surface compaction, and take out rills or wheel tracks from harvest equipment.

Planting corn in fields that have been worked with Vertical tillage equipment can be tricky, and usually requires selecting hybrids bred to handle these soil conditions and the increased trash present. Trelays team has many years of experience and can help you make the right seed selections to match your tillage and filed conditions.

Are Twin Rows for You?

Twin row crops are planted with a staggered seed drop. This allows for more growing room for each individual plant, and it allows each plant to have greater access to water and nutrients, improved light interception, and improves the plants ability to cope with stressful conditions that may develop throughout the season.


Twin Rows are usually planted 7 ½” inches apart on 30” centers. This allows for much better spacing between plants. For example dropping 33,000 seeds per acre in 30” rows would result in 6.3” between plants, the same 33,000 in twin rows would result in 12.6” spacing between plants. This is even more impressive when we go to higher populations, 40,000 seeds per acre in 30” rows puts seeds at a spacing of 5.2” while the same 40,000 seeding rate in twin rows would have 10.5” between plants.

We conducted yield trials across 20 sites last year to compare yields of twin rows and traditional 30” rows. Or results showed at the lower populations there was little response, but at higher populations (above 30,000) we were getting 3 to 5 bushel response to twin rows. Some studies in other areas are showing as much as a 15% yield increase.

As you travel around the Corn Belt this next year, you may see corn fields that look a little different. Our Trelay District Sales Managers have a lot more information on twin rows available, so give them a call today.

Soybean Seed Germination Issues for 2010

2009 is behind us, and most growers are ready to leave it behind and look forward a better 2010. One problem with that idea is the wet harvest season last fall may have an effect on the soybean seed you purchase and plant this year. There have been several reports of soybean seed infected with Phomopsis seed decay. When wet weather causes delays in normal harvest, this fungal disease has the opportunity to infect the pods and seeds of soybeans because of the continued wetting and swelling of the seed and pods. Phomopsis is present in most of our soils and lies dormant until the soybean crop begins to mature. As the soybeans mature, this fungus moves into the pods and seeds covering them with a white, chalky mold growth and causes the beans to have a shriveled appearance. This causes a reduction in seed weight, and a reduction in germination rates of the infected seed. Healthy looking seed may also harbor the fungi within the seed coat. During germination this fungus will grow rapidly and can cause seedling wilt and/or damping off if it does not prevent germination all together.

The best way to manage your risk is plant quality seed. Check the germination on your seed lots to make sure they are 90% or above. This information is printed on the seed bag or on the seed tag of each bag or bulk unit of soybean seed. Another excellent way to control this risk is to use treated seed. Most of the common seed treatments today do an excellent job of controlling this fungus and will greatly increase germination and emergence on seed lots that may have low levels of infection. If you have questions or concerns about your seed quality, talk to any of our Trelay Seeds Reps and they will be happy to assist you with more info about this issue and if seed treatments would benefit your operation.

Hybrid Maturities

Corn hybrid maturity ratings can be confusing to farmers and Ag professionals. One of the causes for this is that maturity can mean different things to different people.

Agronomists and plant breeders talk about corn maturity and think about the end of the grain fill period. This is the point when kernel weight has reached its highest point for the crop. Another term that is used interchangeably is “physiological maturity”. Another term that may be more commonly used is to say the crop has reached “black layer”, because an actual black layer develops at the tip of the kernel.

Grain moisture at this stage can be anywhere from 25 to 40%, and is typically in the mid 30%. It varies from hybrid to hybrid and year to year because of growing conditions in the season.

Most growers think of maturity in terms of “harvest maturity”, or when the crop can be harvested with minimal kernel loss or damage, and minimal drying expense. Usually growers like to see this harvest moisture around 25% or lower, depending upon whether the crop will be stored and fed for high moisture grain or marketed as dry grain.

Traditionally corn hybrids have been rated by seed companies on days to maturity, such as a 98 day hybrid for example. This method of rating hybrid maturities compares new hybrids to other hybrids of known maturity based on their grain moisture content at harvest time. The normal standards are that a hybrid will have a dry down rate of about 0.5 percentage points per day, so if the new hybrid has grain moisture 4% over a known hybrid that is rated as a 90 day hybrid, the new product would be rated as a 98 day hybrid (4 points moisture divided by 0.5 points per day moisture loss equals 8 days). It’s important to keep in mind that this system uses some assumptions about average grain drydown and normal growing conditions, as we well know from this last season, not all years are normal growing seasons.

Another method used to express relative maturities considers heat units, often referred to as growing degree days, or growing degree units. This method takes into consideration the amount of heat accumulated of a specific period of time. It is based on actual temperature measurements and not based on comparisons to other hybrids. Trelay has corn hybrids that range from 2150 to 2925 growing degree units in our product line-up.

The correlation between the two systems is close but not identical. Neither method is perfect because they are influenced by the environmental factors of the growing season, and plant stress on plant maturation such as moisture and or drought as a couple examples. Another factor to keep in mind is that not all seed companies use the same method for hybrid maturity evaluations. Some count days from planting, and some count days from crop emergence, so there can be some variation between two seed companies that are both selling products that are marketed as 98 day hybrids.

So what does this all mean to you? This is just one more reason you need to do some research before making decisions on hybrids. Be careful not to make decisions based on a single plot or test location. The more plots and yield info that you can compare across several sites and multiple years will give you a much better idea of how a specific hybrid will perform on your farm. Your local Trelay Rep will be able to help supply you with much of this information to partner with you and help make the best decision for your farm.

2009 Harvest Results

Harvest results are steadily streaming in...I've added links to Trelay's corn and soybean harvest results under My Favorites.  New data is posted daily, so check back often. 

Corn Test Weights

Corn test weight is a popular topic this year. It is a volumetric measurement; the official definition is “the amount of grain contained in 1.244 cubic feet of space”. The US Grain standard is 56 lbs. per bushel for No. 1 yellow corn, and 54 lbs. per bushel for No. 2 yellow corn. This weight is contingent on moisture content; the normal standard use in the grain industry is 15% or 15.5% moisture. I’m not sure how this system started hundreds of years ago, but my guess is that it was used because scales were not as accessible as today and it was just easier to measure the amount of grain in a wagon or corn crib than to actually take it over a scale.


Many growers associate high yields with high test weight grain, and low yields with lower test weight grain. The truth is that there is very little relationship between yield and test weight. We often see the same test weights across high-yielding and low-yielding environments. Higher test weights will allow you to get more lbs. of grain in a given volume of space, such as a truck or a bin.


What influences test weight?


The physical characteristics of the kernel, such as size, density, shape, and texture of the kernel surface, all come into play. Grain moisture is the most important factor to influence test weight. As grain dries down, it also shrinks, allowing more kernels to fit into a given space or bushel, in this case. This fall, we are seeing corn wetter than we have in many years, so it stands to reason that we will see lower test weights because of the higher moisture.


How much test weights will increase after grain drying varies based on hybrid genetics, condition of the grain, and the temperature that is used to dry it. The following table shows some general guidelines to use for calculations.

Some other factors that influence test weights are: 1) plant stresses during grain fill that could include disease, 2) ear rots and molds, 3) insects, 4) soil or fertility conditions, 5) hail damage, and 6) like this year, in many areas, frost hits before corn reaches Black Layer. Any of these events can disrupt the movement of nutrients and sugars to the kernels.


What if my corn didn’t make it to Black Layer?


Black Layer or physiological maturity signifies the end of nutrient accumulation in the kernel. If corn freezes before it reaches this stage, we can expect lower test weights. The University of Minnesota conducted a study on drying immature corn a few years ago. Their results are listed below (KM = kernel moisture, TW=test weight).

In this study, corn that was in the soft dough to early dent stage actually decreased in test weight after drying. Immature corn that was well dented to Black Layer all increased in test weight to nearly 56 lbs./bu after drying.
Once again, in a year like we have just seen, we can expect to see lower test weights because of higher grain moistures. The good news is test weights will most likely increase after drying, but the amount of increase will vary between varieties and their stage of development of the corn at the time of frost.


References:


Hicks, Dale. 2004 Corn Test Weight Changes During Drying. Minnesota Crop News. http://www.extension.umn.edu/cropenews/2004/04MNCN29.htm
Nafzinger, Emerson. 2003. Test Weight and Yield: A Connection? The Bulletin, Univ. of Illinois Extension. http://ipm.illinois.edu/bulletin/pastpest/200323h.htm
Nielson, R. L. 2009. Test Weight Issues in Corn. Corny News Network. Purdue University Dept. of Agronomy. http://www.agry.purdue.edu/Ext/corn/news/timeless/TestWeight.html
Rankin, Mike. 2009. Understanding Corn Test Weight. University of Wisconsin Extension Publication.