Farmers in Iowa may want to consider putting out their own side-by-side trials if they plan to use a preventive fungicide program to try to increase corn yield in 2008, says Roger Elmore, Extension corn agronomist with Iowa State University.
"There is only a 1 in 4 chance that applying fungicide will be economically sound," points out Elmore. "The only way to really know if you're getting that benefit is to put out some check strips in your own field and do some side-by-side testing with replication." It is not fair or accurate to compare year to year because too many other variables play into yields from one year to the next, notes Elmore. Instead, he advises farmers to split the field into equally sized portions and randomly apply different treatments to each. The harvest area of each treatment needs to be identical.
How to set up your check strips
For example, this could be accomplished by treating a 16-row section with fungicide, leaving the next 16-row section untreated and then harvesting the middle four rows of each section for comparison. That would work if you apply the fungicide with ground driven equipment. However, if the fungicide is applied by airplane, wider strips are necessary to accommodate the spray pattern and alleviate possible drift concerns.
The best way to compare is by replicating the testing process within a field or across multiple fields, he says. You may want to get your neighbors involved.
For example to replicate the trials across fields, if 10 farmers in the area are interested in using a preventive fungicide treatment to increase their corn yield, they should all conduct the tests in about the same way. This will provide the most accurate results.
"Whatever you do, keep in mind that you have to do it in a fair and nonbiased way to get results that are accurate and meaningful," notes Elmore.