Crop Wrap-Up

Seed quality sets the tone for season-long effects in the Southeast.

• By Amanda Huber, Editor •

aspergillus crown rot

Aspergillus crown rot was found in a lot of fields this year.

The Southeast crop seemed to be fated from the start. A drought in late-season 2019 meant that seed peanuts would likely have germination problems. Testing in the seed lab over the winter confirmed this speculation. The difficulty getting a good stand of peanuts set the tone for the remainder of the season.

In The Furrow

University of Georgia Extension peanut specialist Scott Monfort says with the reduced germination rate, some producers responded by increasing the seeding rate. However, work done over the past 10 years from UGA cropping systems agronomist Scott Tubbs on seeding rate has shown that going significantly above the seeding rate does not pay off in yield.

Monfort says, “In twin-row peanuts, we typically don’t go over eight seed per foot of row. We think producers have been pushing this number to get more yield. One single rows, farmers are pushing eight, nine and 10 seed per foot.

“The problem is when you put more than seven seed per foot of row, those seed are on top of each other or are touching. In a year such as this where seed are rotting in the furrow, you are increasing problems with germination even more.”

Seedling Disease

Jeff Davis County, Georgia, Extension agent Jennifer Miller says it was no secret farmers were going to have issues with seed quality this year. But once the crop was up, problems were still prevalent.

“I saw Aspergillus crown rot in abundance this year. Peanut seed that is saved goes through a lot of hot and dry weather and can have a buildup of pathogens in and on the seed. A good seed treatment and in-furrow fungicide applications can and do help, but sometimes that is not enough.
“If you see dead plants in a row and dig them up to find a black smutty-looking growth at the soil line, that’s Aspergillus crown rot.”

Miller says in most years, the death of some plants does not cause significant yield loss because peanuts are good at filling in those spots. “In years like 2020, when stands were not great to start with, we may see differently.”

Substantial Spotted Wilt

Barry Tillman, University of Florida peanut breeder, says the seed quality issues were caused by the drought in late August and September of last year.

“We are still seeing some effects of that. Seed quality issues led to poor stands and that means more problems with tomato spotted wilt disease. I’ve seen a lot of TSWV this year.

“Varieties are the biggest component to minimizing the risk of TSWV losses,” he says. “Look at Peanut Rx and select varieties that have some resistance to TSWV.”

Tillman points out that although spotted wilt was exacerbated by poor stands this year, it has been on the increase for several years. This reinforces the need for varietal resistance to this disease as well as following the other recommendations in Peanut Rx.

White Mold Conditions

Syngenta’s agronomy service representative Wilson Faircloth says conditions in August brought on white mold.

“We have had moisture and high nighttime temperatures, and this has been perfect conditions for white mold. It has even come through some good fungicide programs.”

Wilson says products like Sygenta’s Elatus are good at keeping white mold mostly out of the field. But in years like this where temperatures stayed between 95 and 99 degrees Fahrenheit, it was going to be a challenge to control.

“The difference in this year and last is that in 2019, it showed up in June. This year, we didn’t see white mold until later, but it seemed to appear to be a significant amount all of a sudden.

Fungicides On Foliar Disease

Yet another disease that could be found in peanut fields this season was rust. In Alabama, producers dealt with numerous late-season foliar and soilborne peanut diseases because of the weather, including peanut rust, says Amanda Scherer, Auburn University assistant professor and Extension plant pathologist. It was found on untreated plants in research trials in Headland.

“This is not surprising given the warm, wet weather and bands of rain from the tropical systems that moved through the area. Rust is easily identified by the presence of numerous, tiny reddish-orange pustules on the underside of leaves. The good news is that we are not finding it in treated plots since the disease can be managed with applications of chlorothalonil,” Scherer says.

Hot and dry is always expected in Texas, and conditions this year followed suit. Texas A&M AgriLife Extension specialist Francisco Abello says the U.S. Department of Agriculture crop progress report in late September was an improvement of three percentage points.

“Excellent and good conditions improved from 72% to 75%. This condition is also six percentage points better than last year at this time of the season, but below the U.S. average.”

Notes From The V-C Crop

maturity board

This pod maturity sample of Bailey cultivar was conducted in Isle of Weight County, Virginia, on Sept. 28, 2020.

Dan Anco, Clemson University Extension peanut specialist:

• Warmer weather was needed to help fields dry out for digging and picking.
• Some of the later-planted or longer-maturing runners needed two to three weeks more for optimal maturity.
• If pods were dug and then received rain, inspect the crop for mold and consider putting those in a separate trailer.

Maria Balota, Virginia Tech Extension peanut specialist:

• The 2020 peanut crop has not matured as well as 2019.
• Not being able to plant early or on time this year is one reason for the lack of timely maturity.
• Another explanation is the hot, dry conditions in July, when pollination and peg and pod growth slowed down.
• The yield estimate has been reduced to 3,800 pounds per acre because of maturity concerns.

David Jordan, North Carolina State University peanut specialist:

• Peanuts across the Virginia-Carolina region are progressing well in most cases after a relatively slow start in May and June due to cooler temperatures and in some cases excessive rain.
• Lack of rains and soil moisture in July combined with excessive heat slowed peanut growth and development and likely affected pollination.
• Peanuts planted in June, as well as some planted in May, that did not set pegs until early August may not be mature when dug, which could be the case for 20% of the crop in the V-C region.