US corn farmers must choose varieties with caution

An expert has advised US corn farmers to look beyond yield trial results when selecting varieties for planting.

Iowa State University agronomist and Iowa Crop Improvement Association director Jim Rouse said corn farmers must not forget other key traits when selecting varieties for the next crop year. Farmers also must not base selections only on what has worked in their neighbourhood.

Variety selection is not about identifying which lines did best over the past year, it is about predicting which lines will do best in the future, said Rouse.

Predictive information for yield potential should come only from multi-environment trial averages. Since it is highly unlikely that next season's conditions will be the same as those in any single-location report, farmers will increase their probability of success by selecting a variety that can perform well in many environments, according to Rouse.

As a result, Rouse said a few key variety characteristics to consider are:

• Only multiple-location data should be used to make predictive selection decisions.
   
• Yield trials do not have to be performed on a farmer's farm, on his soil type, or even under his crop rotation scheme to provide relevant data.
   
• Sort the data by yield. Make initial selections based on yield and appropriate maturity.
   
• Once there is a pool of candidates, sort among these to identify lines that have the desired mix of defensive traits.
   
• More information is better information, so use all reliable sources of data.

Because variety selection is a multi-step process, the most effective approach will incorporate several sources of information, Rouse added.