Disease pressure will come to every field. Be ready with these recommendations.
University of Georgia plant pathologist Bob Kemerait reminds growers that once the furrow is closed, all of the management decisions to protect the crop from tomato spotted wilt disease and root-knot nematodes have been made.
For This Season:
• Remember those diseases that can only be managed before the furrow is closed.
• Get good coverage with an effective seed treatment on high-quality seed.
• Is an adjustment needed in fungicides for late leaf spot
control?• Protect peanuts against white mold beyond the four-block spray if conditions favor development and an extended season.
“The same is true for seedling disease and the use of in-furrow fungicides,” he says. “Once the furrow is closed, growers watch struggles with tomato spotted wilt, nematodes and seedling diseases from the sidelines.”
Since diseases will be a threat to every peanut grower’s crop in 2025, at planting is the time to take care of some of these issues.
“Tomato spotted wilt continues to cause significant damage; however, it was less severe in 2024 than in 2022 or 2023, with a 7% and 5% yield loss, respectively. Region-wide, losses were estimated at 3% but were much greater in some fields,” he says.
Kemerait urges growers to consult the 2025 version of Peanut Rx for tactics to reduce risk to tomato spotted wilt disease. Key considerations are planting date, variety selection and choice of at-plant insecticide.
“New varieties have been added to the 2025 Peanut Rx tool. Once the furrow is closed, the die is cast for management of tomato spotted wilt,” he says.
Before And At Planting
Nematodes are often overlooked until they become a significant problem. Kemerait says Georgia farmers could have both the peanut root-knot nematode and/or lesion nematodes in a number of fields with losses occurring across the state in 2024.
“Growers should recognize that important management options for the root-knot nematode include crop rotation, resistant varieties, such as TifNV-HiOL, Georgia-14N, TifNV-HG and Georgia-22MPR, and the use of nematicides as a pre-plant fumigant, as with Telone II, or at planting with Velum, Vydate-CLV or AgLogic 15G.”
Kemerait says a later application of Propulse to reduce damage to the pods and pegs does not replace management decisions made before the furrow is closed.
“Lesion nematodes are an emerging problem on peanuts in some areas, especially when high numbers are present in a field and damage occurs to the pegs,” he says. “Research is continuing; however, the use of Propulse or perhaps Vydate-CLV at pegging time is likely to be an important management tool.”
Seedling Disease
Once peanuts have germinated and cracked the ground, an important seedling disease to watch for is Aspergillus crown rot, especially when conditions are hot and dry at planting or when seed quality is a concern, Kemerait says.
“Because of harvest conditions in 2024, seed may be at higher risk to seedling disease, especially to Aspergillus crown rot,” he says. “Farmer-saved seed is often at greatest risk.”
To manage Aspergillus crown rot, Kemerait recommends producers ensure they are planting quality seed and use an effective fungicide seed treatment, such as Rancona VPD, Rancona VPL, Peanut Prep 2.5 or Trebuset, with excellent seed coverage.
He also says to use an in-furrow product such as Velum or Proline and that azoxystrobin products are less effective against Aspergillus crown rot now than in the past.
Finally, avoid planting into hot and dry soils and irrigate to cool hot soils. Also, manage insects such as lesser cornstalk borers that could come early if conditions are right.
Leaf Spot Recommendations
Leaf spot diseases remain a critical threat to profitability, Kemerait says.
“Peanut leaf spot diseases, especially late leaf spot, were problematic in 2024 but were not as severe as in 2021.”
Factors that increase the threat of leaf spot diseases include environmental conditions, such as rain followed by more rain, which make it favorable for development and spread of disease. “Weather that affects a grower’s ability to make timely fungicide applications,” he says.
Finally, short crop rotations are a risk factor.
“Combinations of these factors put tremendous pressure on some fungicide programs. To prevent losses to leaf spot, especially late leaf spot, it is imperative to stay on a timely, proven program, select fungicides or mixtures of fungicides based upon threat of disease in the field and continue appropriate management programs through the end of the season.”
Kemerait says because of the increased threat from late leaf spot in recent years, some fungicide programs may have changed.
“Late-leaf spot was so severe in some fields in southwestern Georgia, growers there are encouraged to consult with UGA Extension and with your ag-chemical representatives to best understand modifications to fungicide programs during the 2025 season,” he says.
Overall, the critical components of a leaf spot fungicide program include variety selection, crop rotation, timeliness of fungicide applications, selection of fungicides and rate of the fungicides applied.
“In UGA small-plot research trials from 2024, fungicide programs that were assessed for management of leaf spot generally performed as they have in previous years of study. However, growers are advised to carefully consider extended sprays if fields are at high-risk as from short rotations and/or a more susceptible variety,” he says. “In large plot, on-farm fungicide studies conducted by county agents, leaf spot was generally well-controlled by all programs.”
Extend White Mold Control
Although white mold was generally less severe in 2024 than in 2023, Kemerait says that with peanut maturity and harvest being stretched out to nearly 160 days, producers should protect the crop beyond the traditional four-block, 60-to-104 days after planting window ends.
Management of white mold can be improved by early season banded applications of Proline and by protecting the crop during the critical time 60-105 days after planting.
“Consider initiating a program prior to 60 days after planting and extending it beyond 105 days when conditions favor development of white mold or where disease is active in the field later in the season,” Kemerait says.
Be sure to use products known to be more effective against white mold, be timely with irrigation between eight and 24 hours after a fungicide application and consider applying fungicides for white mold control at night or pre-dawn when the peanut plant allows for the fungicide to reach the crown of the plant more effectively. PG
