If peanut growers apply in-furrow fertilizers, they run the risk of hampering their crop's emergence. Extension still doesn't recommend in-furrow fertilizers for peanuts and recently conducted research to confirm again why.
"We are seeing a trend in peanut production here in Georgia with some growers using in-furrow fertilizers. This is something that we do not recommend and have not recommended from the get-go. We've tried to let farmers know that it's just not worth the risk of damaging the seed," said Scott Monfort, University of Georgia Extension peanut agronomist.
Extreme fall weather in 2019 affected the quality of the seed peanuts planted for the 2020 season, resulting in poor stand issues widely seen early in 2020. However, responding to complaints of seed quality issues in 2020, Georgia Extension discovered the use of in-furrow fertilizers likely contributed to some emergence problems also.
"We have noticed some burn associated with the fertilizer when applied over the seed in the furrow," he said.
With the increase in interest in in-furrow fertilizer, "we are trying to make sure this does not get labeled as a seed quality situation. We needed to go back and look at this, collect data to help support or figure out does in-furrow fertilizers cause a problem or not?" he said.
Monfort and team conducted research in Tifton, Ga., this past winter, where they created real field conditions for the peanuts to grow in the Tifton soil type.
The UGA trial treatments included untreated plots and plots with fertilizer applied in-furrow at 0.5, 1, 2, and 3 gallons per acre with a carrier volume of 7 gallons per acre. The peanuts were planted in a bare-ground greenhouse with optimum soil temps and moisture. The plots were 2 feet long with 12 seed planted in each plot. Seeds were planted around 2 inches deep with the treatments applied over the seed prior to furrow closure. Emergence was accessed at 6, 7,8, 9, 10, 11, 12, 13, and 14 days after planting.
The non-treated checks in the trial, or plots that didn't receive an in-furrow treatment of fertilizer, had better emergence overall than plots treated with in-furrow fertilizer at any rate, but particularly the higher rates.
- Untreated had quicker emergence than all rates of in-furrow 6 and 7 days after planting.
- Untreated had better emergence than 2 and 3 gallons of in-furrow at all dates.
Monfort said the study confirmed "do not apply in-furrow fertilizers in peanut."
Several things can negatively affect seed germination in real-world fields. Planting depth, rates, seed quality and weather and soil conditions at planting and at seed harvest the previous year are all things growers manage as best they can. But peanut growers can prevent a potential problem by avoiding in-furrow fertilizers this planting season, he said.
To learn more about Extension peanut recommendations, or dos and don'ts for 2021, get in touch with your local Extension county agent.