Timing, method and return on investment are some of the questions producers have on replanting.
The standard recommendation for a good peanut stand is to plant six seed per foot of row to achieve four plants per row-foot. Poor seed quality, improperly calibrated equipment, planter failure or malfunction, or planting into cool, dry soils can affect the likelihood of achieving a good stand of peanuts. Situations arise to create less-than-optimal outcomes even though peanuts are not the most difficult crop to achieve a quick germinating, uniform plant stand.
The following are some questions and answers growers may have on achieving an acceptable stand and what level should trigger a replanting of the field.
Q: If my stand is coming up with skips and gaps, how long should I wait before deciding whether to replant? A:
Give the seed plenty of opportunity to germinate, says University of Georgia cropping systems agronomist Scott Tubbs, who has studied peanut replanting for nearly a decade. Producers will want to make sure they have the full plant population before making any decision about supplemental planting, he says.
“At two weeks after, you would still be getting some straggler plants coming up and you would not know exactly what your final plant population will be. You’re okay to replant at two weeks, but you may not need to.
“Waiting four weeks after the original planting was unsuccessful in gaining an advantage over leaving the original plant stand alone,” Tubbs says. “We found that three weeks after the original plant was the timing that worked best in our replant projects thus far.”
Q: Will replanting improve yield over a poor plant stand?
Replanting does not improve yield over a poor plant stand as often as you might think, Tubbs says. “Only when plant stands were as low as one plant per foot of row did replanting improve yield to a point that it would be economically viable to justify the cost of replanting.”
However, a primary concern with skips and gaps in a peanut stand is the potential for Tomato Spotted Wilt Virus.
“In field trials, if you look at the rows with one plant per foot with no replanting, this plot has a tremendous amount of TSWV,” Tubbs says. That’s the real risk in not achieving the needed plant density.
If plant stands are at least 2.5 plants per foot of row, whether twin row or single row, strip-till or conventional tillage, and the stand is relatively uniform without large gaps, the chances of gaining a return on the investment of replanting a field is very low, says Tubbs.
Q: How should the field be replanted?
If the decision has been made that the current stand is not sufficient, Tubbs says supplementing what is already there is the best method of replanting over terminating plants already in the field.
“In our research, there were essentially no circumstances where burning down the original stand of peanuts with a herbicide and starting over with a complete replanting of peanut was worthwhile,” he says. “Any instances where replanting showed the potential for a benefit, it was when the poor plant stand was left in the field and peanut was replanted by offsetting the planter two to three inches to the side of the original row and placing supplemental seed in the ground.”
In research on single-row planting pattern, yield is increased by supplemental replanting when stands were below 2.5 plants per foot, and supplemental replanting was achieved by planting 3.5 inches off the original row. In this instance, a reduced replant rate of three seed per foot was used.
On twin rows, if the initial stand is less than three plants per foot, the best option is also to supplement the initial stand with a seeding rate of three seed per foot.
For more information on replanting decisions, see “Peanut Pointers” from David Jordan, North Carolina State University Extension state peanut agronomist, and Kris Balkcom, Auburn University Extension specialist, on pages 21 and 22. PG