Extremely high daytime temperatures, coupled with extended periods of drought during the critical pod-set stage of peanuts, may result in a significant loss in yield across the Carolina-Virginia peanut belt.

The biggest threat is from the heat. Temperatures in excess of 95 degrees significantly reduce pollination and peanut plant growth.

Peanuts are an indeterminate crop, and peanut plants will keep on blooming, which can be a good thing or a bad thing. For certain, it will make for some difficult management decisions at harvest time.

Suffolk, Va., grower John Crumpler says his peanuts look okay and mid-August rain no doubt helped the appearance. His concern is the impact record heat in June and July had on pod set and development.

“We lost our corn crop to the heat and drought, but August rains and cooler weather has helped our peanuts and cotton. I think we have a chance to have a decent peanut crop,” he says.

If the maximum daily temperature gets all the way up to 104 pollen viability can drop to around 70 percent and seed set to around 50 percent. Southeastern Virginia had several days in July and early August with temperatures above 100 degrees On one July day, the temperature topped out at 106 degrees, beating the all-time record by five degrees. 

Crumpler, who farms near the Tidewater Agricultural Research and Extension Center, carefully monitors their weather station. “I’m only a couple of miles away from the station, and several times they would get a trace of rain and I wouldn’t, and vice-versa. From April to August, neither of us got much rain,” he adds.

The Virginia grower says he doesn’t expect nearly the peanut yield Virginia peanut growers have produced the past couple of years, but contends peanuts have time to recover to produce a decent crop. The big concern, he stresses, is how much pod set was reduced by the heat.

In South Carolina, Clemson peanut specialist Jay Chapin says, “Peanuts planted mid-May were 86 DAP as of Aug. 9. Nearly all our crop in South Carolina is in the R-6 growth stage which means the oldest pods have seeds filling the hull, but no darkening was apparent by mid-August on the inside surface of the hull.”

Peanuts planted the last week of April are in the R-7 stage which means the oldest pods are starting to mature and show some darkening on the inside of the pod wall.