Using variety testing data to select soybean varieties: Guidelines for practitioners

1. What is the primary purpose of university soybean variety testing programs?

a. To determine which company produces the highest seed sales.
b. To provide reliable, unbiased performance data across environments.
c. To promote newly released varieties exclusively.
d. To establish national yield records.

2. What is the benefit of a multilocation, multiyear trial over a multilocation single-year trial?

a. Better yields.
b. Better grain quality.
c. Improved selection accuracy.
d. None of the above.

3. What does a Least Significant Difference (LSD) value represent in variety trial results?

a. The highest yield recorded in the study.
b. The average yield difference between early and late varieties.
c. The variability caused by planting date.
d. The minimum difference required between varieties to be statistically meaningful.

4. When comparing two soybean varieties, if the yield difference between them is smaller than the LSD value, what does this indicate?

a. The higher-yielding variety is clearly superior.
b. The varieties are statistically different.
c. The yield difference may be due to random variation.
d. The trial should be discarded.

5. Selecting varieties that consistently perform well across multiple environments is generally a more reliable strategy than selecting the single highest-yielding entry in one test.

a. True.
b. False.

6. Which of the following is an objective of this article?

a. To describe replicated small-plot trials and unreplicated on-farm large strip-plot demonstrations, including attributes of each type.
b. To recommend best-performing soybean varieties across all U.S. regions.
c. To provide best management recommendations for high-yielding soybeans in Louisianna.
d. To provide seeding rate recommendations.

7. Which of the following is an attribute of small-plot trials?

a. Easier to conduct in many locations, including farmer’s growing conditions.
b. Easier to evaluate many varieties.
c. Easier to gain farmer’s trust due to local growing conditions.
d. Easier to locate areas of stress and screen for resistance.

8. A variety ranked first in yield at one test location will typically rank first across all locations in a region.

a. True.
b. False.

9. Which of the following traits did the article NOT list as one to be considered when selecting soybean varieties?

a. Plant height uniformity.
b. herbicide resistance.
c. growth habit.
d. seed cost. 

 

10. What is usually the width of the strips in large strip-plot demonstrations?

a. 2 ft.
b. 5 ft.
c. 10 ft.
d. The same as the width of the planting equipment.

11. In replicated small-plot soybean variety trials, randomization and replication are used to reduce the impact of field variability on yield comparisons.

a. True.
b. False.

 

12. When comparing soybean varieties within a location-year, statistical groupings based on LSD indicate that

a. all varieties differ significantly from each other.
b. varieties sharing the same letter are not statistically different.
c. the highest-yielding variety is always superior.
d. the variety with the lowest CV% is the best performer.

13. Why should caution be exercised when interpreting results with missing data?

a. It can introduce errors in variety selection within locations.
b. It can increase the statistical power of the trial.
c. It can introduce errors in variety selection across locations.
d. Both a and c.

 

14. In on-farm unreplicated strip-plot demonstrations, it is often observed that there can be significant spatial yield variation within a single variety (Figure 2). What is the main driver of this variability?

a. Genetic variability.
b. In-field nongenetic variability.
c. Different management choices within a strip.
d. Both a and c.

15. In what formats are variety trial datasets typically available?

a. Printed publications.
b. Downloadable online datasheets.
c. Online selection tools.
d. All of the above.