Six Things to Consider When Evaluating Plot Data for Variety Selection

With harvest upon us, there will be a lot of plot data circulating to showcase performances. It’s important to understand what type of data you’re looking at and how to interpret the information. A lot of times, people just want to see which products placed first, second or third in each plot. However, plot results are useless unless the winning information is incorporated into a larger data set. 
For example, if a farmer made their seeding decision for corn or soybeans based off the performance of a given plot, they are statistically taking on a higher level of risk. Whichever products placed in the top three of the plots may be consistently in the lower 1/3 of results across the county or region. So it is especially important to evaluate plots from several locations that have several different agronomic management practices. 
Farming in general is a very risky business, but not as risky as going to Vegas and gambling …. However, if you were a gambling person, would you place a high cost bet on a product or concept that you saw win one plot? Hopefully, you said no; the risk is too high. On the other hand, you would feel comfortable placing a high cost bet on a product or concept that was tested across 200 plot locations, across several soils, planting dates, planting populations, etc. and has a 70-80% win ratio compared to other options. In fact, you would feel very comfortable and confident that the risk would generate a good and safe return. 
Not everyone enjoys reviewing data or drawing conclusions from it. That is why it’s important to first recognize that you’re not this type of person and second seek out a person who does enjoy reviewing data and placement trends. 
At the end of the day seed—for soybeans or corn—is the single most important decision that could be made on an acre and can have the biggest influence on a profitable season. Nevertheless, a great product can be misplaced or mismanaged and perform unfavorably, which is why working with a trusted Illinois CCA who focuses on seed and agronomy is invaluable. 
Items to look for in plots and trials: 
1. How many checks where in the plot? 
a. Hopefully one on each end and a few in the middle, depending on the side. 
2. Are the row widths in each plot equal to yours?
a. This can impact the amount of sunlight captured per acre.
b. Impacts occur when the canopy closes rows to minimize weeds, herbicide application during flowering and reduce soil surface temperature and loss of surface moisture.
3. Seed Treatment
a. If a plot was using a high-end treatment (insect + fungi + inoculant + SDS), and you’re not planning on using this level of treatment, your experience and results may vary from a given plot.
4. Planting date
a. Was it planted earlier, equal to or later then what you typically plant?
5. Planting Population
a. Population can vary a lot in plots and in fields—anywhere from 90,000-180,000 seeds per acre.
6. Field History
a. Does the given field have a history of SDS, soybean cyst nematodes, frog eye leaf spot, etc.?
b. It could be important to know which soybean was in the field the last time the plot field was in soybeans. 

Todd Steinacher
Steinacher is an ISA CCA Soy Envoy alum and currently supports ISA on agronomic content as well as serving as an Illinois CCA board member. Since 2015, he has been a regional agronomist with AgriGold in West Central Illinois. His previous experience includes 10 years as a sales agronomist in the GROWMARK-FS system. Steinacher has an associate degree from Lincoln Land Community College, a B.S. in agronomy and business from Western Illinois University and a master’s degree in crop science from the University of Illinois at Urbana-Champaign. If you have any questions for him about this article, he can be reached at



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