I’ve written previously about why North Carolina corn growers should feel comfortable planting non-Bt refuge corn, but the performance of non-Bt hybrids in the 2022 OVTs adds one more reason to the list. We have a collaborative project to evaluate non-Bt and Bt hybrids for yield on growers farms across the state. While these on-farm tests are planted in strips using grower equipment (much like the on-Farm Cotton Variety Evaluation Program), the OVTs are planted into smaller plots. There is value in both approached and we hope to make the on-farm non-Bt and Bt information available soon.
Growers can use the Variety Selection Tool to search for these hybrids that were planted in the 2022 OVTs. An identifying column entitled BT Status will identify whether the hybrid is a Bt or non-Bt hybrid when querying or filtering the data.
Three of the non-Bt hybrids and two of the Bt hybrids tested in the on-farm program were included in nine OVT locations in 2022. All were mid-maturing hybrids produced by DEKALB and Pioneer. Non-Bt hybrids from DEKALB performed extremely well, landing in the statistically-highest yielding group in three out of nine locations. Furthermore, the non-Bt hybrids out-yielded the Bt hybrid we were interested in comparing in six out of nine locations. The non-Bt hybrid from Pioneer, on the other hand, was not a good fit. It was often among the lowest yielding hybrids in a given location and only out-yielded the Bt hybrid we were interested in comparing in two out of nine locations. Keep in mind that we only evaluated a single non-Bt hybrid from Pioneer and that there were likely other hybrids from this company that would have yielded much better. This highlights the fact that:
1) A non-Bt hybrid with good genetics can perform as well as many Bt hybrids when planted on time and placed in the correct environment.
2) A non-Bt hybrid placed in a poor environment will perform poorly, even in the same relative maturity as other Bt hybrids- genetics matters!
We have measured this before. Here are yield results from three non-Bt hybrids grown in replicated trials for four years at the Tidewater Research Station in North Carolina. Note that the average yield difference between the top yielding non-Bt hybrid and the lowest yielding non-Bt hybrid is 24 bu/A. Growers should work with their seed dealer to ensure that they are planting the correct non-Bt refuge hybrid for their environment.
Average yield of three non-Bt hybrids across four years. Error bars represent standard error. Hybrids that share the same letter did not yield statistically different.
