Large Check, Small Seed, Significant Impact

Figure 1. Various soybean varieties exhibit differences in Sudden Death Syndrome foliar symptoms. (Photo by Nathan Mueller)
Figure 1. Various soybean varieties exhibit differences in Sudden Death Syndrome foliar symptoms. (Photo by Nathan Mueller)

Large Check, Small Seed, Significant Impact October 11, 2017

As fall harvest gets underway, so do early seed discounts and seed buying decisions for 2018. In times of tight margins, every extra bushel produced and every dollar spent on production inputs like seed (10%), fertilizer (13%), and chemical (9%) become more acute. One of the first routine management decisions you make and one of the most important is corn hybrid and soybean variety selection.

No Small Decision

How much yield difference is there between corn hybrids and soybean varieties? On average, regional third-party trials have shown a 15 bu/ac difference in soybean variety performance and a 50 bu/ac difference in corn hybrid performance. At current commodity prices, that is a difference of $135 per acre for soybean varieties and $150 for corn hybrids in potential revenue driven by a decision you made a year earlier. Soybean variety selection (Table 1) ranks first for management factors driving yield differences and corn hybrid selection ranks second.


Table 1. Impact of various management decisions on soybean yield
RankManagement FactorYield Difference
(bu/ac)
1 Variety Selection 15
2 Planting Date 8
3 Weed Control 8
4 Phosphorus Fertility 5
5 Crop Rotation 5
6 Row Spacing 3
7 Seeding Rate 3
Source: Why Soybean Variety is Critical to Improving Farm Yield in CropWatch

When selecting seed for next year's crop, following are some key points to consider. Also see Which Bt Traits Do You Need to Purchase?

Price Genetics

The price per unit for technology traits can vary $5 in soybeans (for example, between RR2s) and easily ranges from $10 to $60 per unit in corn. Don’t pay for traits or add-on treatments  you don’t need. Consider weed, disease, and insect problems you’ve experienced in the past and choose accordingly. Overall, worrying about seed cost versus yield performance is more critical in corn than in soybeans.

Early Orders

Capture early seed discounts. Why? Seed companies have internal data showing the average performance difference among their products. They consider such performance in regional placement and share this through recommendations for your region. Ask them if the supply for some products they recommend is a little tighter than others and consider ordering those sooner if they sound like a good choice for your farm. It's your call on how many companies or seed dealers you want to work with when selecting hybrids/varieties. Once 2017 yield data is available from various sources, evaluate the hybrids/varieties you ordered and make a substitution if needed. Your seed dealer will likely make this substitution, assuming seed supply exists, but discuss this with them ahead of time.

Proven Performance

Look for yield stability or proven yield record across locations and years if possible for each variety and hybrid. Use multiple data sources including third-party trials, company trials, and on-farm results. For on-farm comparisons, precision ag data management software and services can be used to summarize performance from past seasons. Ask your seed representative to run comparison analysis between hybrids and varieties that you are considering within their company to help with selection. Though not all hybrids and varieties are tested in third-party performance trials, these tests are a great source of information:

Mix Maturities

Soybeans — A recent analysis of third-party soybean data from 2012-2016 in eastern Nebraska and from recent farmer surveys across the Midwest show that soybean maturity accounts for less yield difference than do variety and planting date. Consider diversifying maturities, for example in east central Nebraska use a 2.4 to 3.4 maturity. In Nebraska, short periods of heat/drought for two weeks during early or late August may impact fuller season varieties more or less than the shorter season varieties, depending when or if these conditions occur.

Corn — Choose hybrids that will reach maturity at least 10 days before the first average frost for your area. Plant multiple hybrids with varying maturities to spread out risk during pollination. This will also widen the harvest interval. Plant earlier maturing hybrids to facilitate cover crop establishment.

GEM

Assess the interaction between genetics, environment, and management (GEM). Make a list of specific traits you want for certain management practices (irrigated, continuous corn, etc.) and fields (river bottom, terraced ground, etc.). Remember, no matter how good your management, maximum yields won’t happen without the best varieties or hybrids. Your trusted agronomist can help you with selection, but it's up to you to remember your product placement at planting! 

We have asked numerous farmers over the years how much time they spend on corn hybrid and soybean variety selection and placement. As agronomists, the answer has been either disheartening or satisfying. May it be the latter.