Agronomy Articles
Corn & Soybean Agronomic Facts
Corn Facts
Q: How many Growing Degree Days (GDD's) from planting of corn to emergence?
A: 100 GDD's
Q: How many Growing Degree Days (GDD's) to emerge a new corn leaf?
A: 80 GDD's
Q: Under moderate weed infestation, what is the optimum for herbicide application and what is the potential loss for every day delay past optimum?
A: V2-V3 is optimum with 1-2 bushel loss per day past optimum spray date with moderate weed infestation.
Q: How many ear shoot on average does a corn plant typically have?
A: Typically 7, with the top ear shoot being the harvestable ear.
Q: What plant component does a corn tiller derive from?
A: A corn tiller is a modified ear shoot.
Q: When are the corn kernels around determined in a corn plants life cycle?
A: V5-V8
Q: When is ear kernel length determined in a corn plants life cycle?
A: V5-V12
Q: How much water does the average corn field with average to above average yield potential require?
A: 18-22" of water
Corn Fact: If a corn plant emerges 1 leaf collar behind a neighboring plant it is still a viable plant, if it emerges 2 collars behind… it's a weed!
Soybean Facts
Q: Does seed size of soybean seed planted have any effect on soybean yield?
A: No. Shawn Conley, Soybean Specialist, University of Wisconsin
Q: How many Growing Degree Days (GDD's) does it typically require from planting to emergence?
A: 100 GDD's
Q: According to university data, what is the average percentage of emergence on a typical stand of soybeans planted?
A: Approximately 75-78% emergence.
Q: Under normal planting dates, how large of a gap in plant-to-plant spacing can an individual soybean plant "fill in?"
A: 2 ½'
Q: According to university research, what is the optimum spray date under moderate weed infestation for soybeans & what is the potential loss per day of delay?
A: Answer: Under moderate weed infestation, when weed reach 6" in plant height and for every day delay is a potential 1/3 to 2/3 bushel loss per day of delay.
Q: It is June 20th and a very severe hail event occurs and you end up with a consistent viable plant population of 50,000 plants per acre... do you replant?
A: No. Research shows that to replant at this particular date results in a potential of 60-65% of your yield potential & 50,000 consistent viable plants per acre will typically achieve a similar outcome. Shawn Conley, Soybean Specialist, University of Wisconsin
Q: How much water does the average soybean field with average to above average yield potential require?
A: 14-18" of water
Accessing Flood Damage to Soybeans and Effects of Planting Date on Soybean Relative Maturity
Scenario: Soybeans are submerged below water for over 48 hours... will they die?
Answer: This really depends on temperature, humidity and cloud cover. Soybeans can generally survive for 48-96 hours submerged below water.
- Higher daytime temperature, high humidity and sunshine increases plant respiration, which depletes oxygen levels and increases carbon dioxide levels. Generally this scenario substantially decreases the amount of time soybean will survive submerged below water.
- Lower daytime temperatures, cloud cover and low humidity decreases plant respiration, decreases oxygen need, keeping carbon dioxide levels lower. These environmental conditions will allow soybeans to be submerged below water for a longer period of time with lower plant fatality.
Scenario: A field is submerged for nearly a week and appears to experience almost 100% fatality. It is June 17…what should I plant?
Answer: Generally, soybean yields this late in the season results in 30-40% decrease in production, but there are management practices you can do to increase your odds to success!
- First, it is strongly advised that soybeans are drilled and not put in with a corn planter in 30" rows. 30" rows will more than likely not canopy, loosing valuable moisture that is typically trapped below the soybean canopy.
- Second, try to have a minimum of 180,000 final soybean populations. This will require a minimum of 200,000 soybeans dropped in a 6-10" row spacing.
- Third, if planting in early to mid-June try to remain with full to mid season soybeans. If planting in the last 2 weeks of June try to plant mid-season soybeans.
- Fourth, strongly recommend thoroughly inoculating soybeans and the use of a fungicidal seed treatment, since rhizobium numbers could be impacted by flooded soil and fungal diseases may be elevated in moist damp soil profiles.
*If you are to stick to these guidelines you will increase plant height, increasing your odds of harvesting more of the lower pods… increasing your yield potential!
Information Sources: Accessing Flood Damage to Soybeans, University of Wisconsin Agronomy, Soybean Research & University of Wisconsin Extension.
Corn Nitrogen Calculator
The corn nitrogen calculator was derived from a collaboration of seven states, Minnesota, Illinois, Iowa, Wisconsin, Ohio, Michigan and Indiana. Download here
Dr. Dave Gedge's Research Summary
As an independent regional seed company, Legend Seeds is able to access traits and the best genetics from all major sources. As you look at the product line up note that Legend Seeds offers the latest in traits from Monsanto, Dow/Pioneer, Syngenta, and Bayer CropScience. Only an independent company like Legend Seeds can do this.
With the continued growth in sales at Legend Seeds, we are able to increase the amount of research we do. Our research is directed at finding the best genetic package to fit the climate, soil, and disease, insect, and market needs of the area we serve. In particular, this year we have been able to increase substantially our commitment to finding genetic solutions to problem soil conditions.
Evaluation of corn hybrids for silage value is another area to receive increased research effort. Legend Seeds will be participating in a cooperative evaluation program to determine dry mater yield and nutrient value of silage made from various corn hybrids. This will be a large data base set which can be used to select silage hybrids with confidence. Data will become available during the fall of 2007. Keep in touch with your DSM for specific details.