Applying fungicide at the right time maximizes profits, and adding a fungicide at the R3 growth stage results in a return on investment of $17.68 per acre, according to Beck's Practical Farm Research.
“The R3 growth stage is the key time to apply a fungicide in soybeans and will last approximately ten days,” says Travis Burnett, field agronomist at Beck’s.
At the R2 growth stage it is too soon to apply as the plant’s upper nodes haven’t been developed, pod retention and seed size wouldn’t be impacted. At the R4 growth stage, it is too late to apply as the plant’s lower nodes would be far too developed to make an impact.
Beck's rolled out the PFR Proven endorsement in 2007. To become PFR Proven, the product or practice must undergo three years of testing at multiple locations, see a positive yield gain each year and have a positive average return on investment over the three years.
The time of the day fungicide is applied is another factor, according to the research. During the testing, when sprayed at 8 am there was an average of $12.97 per acre. Whereas, at 3 pm, the average was $7.63 per acre.