What is in this article?:
- Research aims to take the guesswork out of determining peanut maturity
- Make an indeterminate peanut act more determinate
- Eliminate immature peanuts and improve the flavor profile
Determining peanut maturity has always been an inexact science.
Research is looking at terminating flowering to improve maturity distribution.
USING HERBICIDES TO terminate peanut flowering could lead to a more exact way of determining maturity, says Marshall Lamb, research director for the National Peanut Research Laboratory in Dawson, Ga. Lamb is shown here at a field day this past summer.
Make an indeterminate peanut act more determinate
The research, he says, is an attempt to make this indeterminate peanut crop more determinate, and it’s a way to increase the amounts of black, browns and oranges on the profile board because they are the biggest, densest and most mature peanuts. They have the highest oil-to-water ratio so when you dry them they don’t shrink.
“Our concept was to look at two different herbicides. One is glyphosate and the other is diflufenzopyr Na, which is BASF product,” says Lamb.
“We wanted to see if we could come in at different times and terminate flowering. When you’re harvesting peanuts on the black part of the board, you’re blowing lighter ones out of the back of the combine.
“Another problem we have is getting the less mature ones to mature quicker because when a flower turns into a peg and hits the soil, they’re going through the most rapid cell division and cell elongation of any part of the entire plant.
“That is stealing energy from something you will never harvest and never benefit from and not putting the energy where it is most needed.”
This research, says Lamb, is focused on stopping the flowering at a set time to petition the energy away from the peanuts that won’t be harvested.
“We chose our timing based on the black part of the traditional maturity board. We were looking to get about a 15 to 20-day break in the flowering cycle from approximately day 100 to day 110, depending on where the crop is.
“When we started this, we didn’t know which rates to use, so we looked at different rates with these two herbicides.
“We used a 41-percent formulation of glyphosate, which is the case with most generics. For weed control, you’d use 32 ounces per acre. But we used different rates at 2 ounces per acre, 4 ounces per acre, and 6 ounces per acre. We used the lower rates because we don’t want to kill the peanuts. We don’t want a lot of foliage damage — we just want to terminate the flowering.”
There’s a reason for choosing glyphosate, says Lamb.
“If you remember when Roundup Ready cotton first became available, we were spraying it with Roundup almost season-long. But we discovered that the late-season application of glyphosate was affecting the pollination of the flowers in cotton and reducing yield. When we discovered that, we knew best how to use it.”
Diflufenzopyr is being used as a herbicide, but it also has been shown that it will interrupt the flowering as well, he says.
“We’ve got three different rates of each of these, and we’ve got irrigated and non-irrigated, three different timings — one time at day 100, one time at day 110, and then we have a repeated application at 100 and 110, so it’s a double application. We’re trying to determine timings and rates.”
The research includes an untreated check and hand-removal of the flowers every day for 20 days, he says.