Hybrids/varieties included in our variety testing program usually come from two sources:
- Public institutions including the University of Nebraska, and
- Seed companies marketing in Nebraska and neighboring states.
Those from public institutions are without charge while those originating from private companies are entered for a nominal entry fee following submission of an application form.
Companies are not limited on the number of entries.
This approach is often overly criticized for possible crowding effect. This is based on the flawed assumption that a company with the highest number of entries has more chance of getting hybrids/varieties hitting the highest yield performance. But the chance such effect could occur is under the improbable condition of all entries from all participating companies being equal in performance, or having the same genetics with different names. In the absence of this condition, the likelihood of a poor yielding hybrid beating a good hybrid just by overcrowding is nil.
Entries are evaluated using a randomized complete block design with four to six replications.
We emphasis selecting a site representing the growing environment as well as giving equal chance of performance for the entries included at the site. The site selected for the testing and the field plan will ensure more or less similar growing conditions for the entries such that differences are due to the genetics and not due to the environment.
In addition to blocking obvious gradients at testing sites we use special analysis to evaluate and adjust field variability not conspicuous at site selection and field plot layout.
Testing locations are predetermined based on representation of Nebraska crop growing environments for that specific crop. The seed companies determine what hybrid they want tested at what location.
Soybeans are planted in early and late maturing groups based on maturity information provided by the companies entering the hybrids.