Research Spotlight on Replanting Decisions

Scott Tubbs, cropping systems agronomist with the University of Georgia in Tifton, Georgia, focuses his research efforts on peanut agronomic research. He initiated several trials to assess replant decisions in peanuts. Through his research he is assessing what is the original plant population and at what point does it trigger a replant decision for a farmer based on that original plant population. He has tried several different methods of replanting that could include replanting by planting next to the original row or wiping out the original row completely and just starting over with an entire new replant for the full field being a maximum seeding rate.

In one trial in Tifton, Georgia, Tubbs has a replant trial where he is only replanting the initial gap in the field by forcing a two foot, four foot or six foot gap in the row where the original plants were pulled out of the ground and then replanting that either in that gap or replanting the entire row. This can make it easier on the equipment and the driver to not have to assess where the gaps occur but the final phase of this project will be to hopefully use equipment where Tubbs can assess the gaps in the row while the machinery is moving through the field and only replant the sections of row that need to be replanted based on the research that he has for yield drag, for a length of gap and the potential to improve grade as well.

The replant trials have multiple phases and locations including one in Plains, Georgia at the Southwest Georgia Research and Education Center. The research projects in Plains this year are in phase 2 where they are assessing only the yield drag alone in the length of gap. In those trials, Tubbs has one foot, two foot and three foot gaps in the row after the initial planting by forcing and pull thinning those plants out to force those gaps in the row and those gaps of one, two, and three foot occur either twice or three times in each 40-foot row. So essentially, the plots end with nine feet out of 40 feet of row missing from the field or roughly very close to a 25 percent stand decline from what the original plant stand could be, but that research by itself does not assess the replant decision.

That’s where our phase three project comes into play in Tifton this year where we are not only removing the gaps but we’re also replanting the gaps in the gap alone or with a full row replant so there are multi phases to this project that occur over time and in multiple locations, Tubbs says. The ultimate goal of this research is to help farmers assess a plant stand in the field and determine whether that plant stand is either uniform enough to leave alone or if it is spotty enough to require a replant decision, to helping them improve either yield or grade or hopefully both.

The research by Tubbs goes into more than just replant decisions. Some of his work focuses on rotations, how many years between peanut and how does that affect the plant when it grows in the field. Shorter rotations have a tendency to increase disease and nematode issues on peanut and can cause issues with herbicide resistance with weeds. Tubbs is also focusing some of his research on inoculants and inoculate formulations, when to use inoculants, how much benefit do we get from inoculants either in short rotations versus long rotations. He has also focused some research effort on tillage research conservation or conventional tillage research and seeding rates.

View the 2017 Georgia Peanut Tour Photo Album.