Authors: Dr. Kiersten Fullem, Postdoctoral associate, UF/IFAS Dept. of Plant Pathology; Ethan Carter M.S., UF/IFAS Regional Specialized Agent III, Jackson County; Dr. Nicholas Dufault, Professor and Extension Specialist, UF/IFAS Dept. of Plant Pathology

Introduction to PeanutLink

PeanutLink is a new platform designed to support Peanut Extension by tracking reports of peanut diseases, insects, weeds, nutritional deficiencies, and other production issues across the Southeastern United States. Extension agents and experts submit observations from the field which are then used to create searchable records and real-time maps of production issues across the region. The project is led by UF/IFAS Plant Pathology and funded by the Southern IPM Center, with collaborators in Virginia, North Carolina, South Carolina, Georgia, and Alabama. The PeanutLink platform is part of the Bugwood system of data collection and management tools.

The following is the first article that summarizes data submitted to PeanutLink.

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Peanut Rust

Peanut rust has been reported recently in Seminole County, GA and Levy County, Florida. Peanut producers across Florida, Alabama and Georgia should be on the lookout for rust this season, including areas where the disease is not typically a concern. Rust caught several growers off guard during the 2025 season, particularly in parts of the Florida Panhandle. Based on recent reports, growers throughout Florida should remain vigilant and monitor fields closely for signs of rust as the season progresses.

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Scouting for this disease is particularly important as it can spread extremely quickly once introduced to an area, especially under rainy or windy conditions. Orange rust spores appear on the underside of peanut leaves and can be seen with or without a hand lens (Figures below).

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When rust is present in a field, it may be wise to shorten spray intervals from 14 to 10 days, especially in areas that are receiving frequent rainfall. Although not an exhaustive list, products including Abound, Headline, Priaxor, and Elatus have been very effective at managing rust. If using Abound or Headline to treat rust, it is important to mix them with another fungicide product to get good leaf spot activity.

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White Mold

PeanutLink users in South Carolina, Georgia, and Florida are reporting the appearance of white mold (Agroathelia rolfsii; AKA southern blight) in their areas. High daytime temperatures and high humidity favor white mold development, and warm humid nights (over 75 F) create the perfect growing conditions for the fungus.

Users should be on the lookout for white mold, especially if the weather in their area is currently hot and humid. Although not an exhaustive list, products including Convoy, Elatus, Excalia, and Fontelis provide strong white mold control. It is important to note that Convoy has no leaf spot activity, and an additional product would need mixed with it to provide control.

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Other Diseases and Issues Reported in Peanuts

Peanut Early and Late Leafspot

There have been several reports of early leaf spot from Florida and Georgia, and late leaf spot has also been reported in Florida, Georgia, and South Carolina. The predominant leaf spot type varies by geographic location, and both diseases may be present in some areas. Resistance has been documented to Group 11 fungicides (Headline, Abound, etc.) in leaf spot pathogens, and it is not recommended that this group of products be sprayed alone. They should be tank mixed with another additional product (chlorothalonil, tebuconazole, etc.).

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Tomato Spotted Wilt Virus

Tomato spotted wilt virus (TSWV) has also been reported from Florida, Georgia, and South Carolina. This virus is vectored by thrips and can be extremely destructive. The most effective management strategies for TSWV are preventative, leaving few to no options for this period of the growing season. However, knowledge of the presence of the virus and its vectors can help inform next year’s management decisions.

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Damping Off

Damping-off of peanut seedlings has been reported from one location in Florida. This disease is associated with a complex of fungi and oomycetes, but in this case, was found to be associated with Pythium.-

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Insects

Recent insect reports include lesser cornstalk borers in Florida as well as corn earworm and potato leafhoppers in South Carolina, and thrips in both states.

Feeding by potato leafhoppers causes “hopper burn”, the characteristic symptom of which is yellow v-shaped lesions on the ends of leaflets. Potato leafhoppers may move in and out of fields during the course of the season, but July is a common time to see severe hopper burn. There are no action thresholds for potato leafhopper and it is generally thought of as a cosmetic pest (causing the yellow leaf tips). However, under heavy pressure or stressed conditions (slow growth) an insecticide application may be warranted. When treating caterpillars, pyrethroid products will control this pest as well. Hopper burn symptoms remain visible and last long after the insect is gone from the field.

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Weeds

PeanutLink is currently receiving a great number of reports regarding weeds. Groundcherry, Benghal dayflower (AKA tropical spiderwort), wild poinsettia, yellow nutsedge, sicklepod, nightshade, and goosegrass have all been reported from Florida. Peanuts do not compete with weeds as well as some other crops and so, effective weed management throughout the growing season is important to protect yields.

Late season weed management can be difficult for many weed species, it is important to control weeds when they are small. Once weeds are grown, control options narrow to just a few products and even then, their efficacy ratings offer more fair-to-good control compared to excellent.  Products such as Ultra Blazer, Cobra, and Strom provide control activity for groundcherry and wild poinsettia. Cadre is the staple of any nutsedge control program in peanut and it also provides some activity on wild poinsettia and tropical spiderwort. Sicklepod is another perfect weed example with few post herbicide options, 2,4-DB (fair), Cobra (poor-to-fair) and Cadre (good-to-excellent). The same products that provide broadleaf weed control in peanut do not work on grasses. Grass weed control is limited to clethodim products (Select, Avatar, etc.), Poast, or Fusilade.

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Other Issues

Lastly, we have had a great number of interesting reports lately that fall into the “other” category.  There have been reports of nutritional issues, including boron and potassium toxicities (Florida) and manganese deficiency (South Carolina).

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While boron is an essential micronutrient for peanuts, it also has the potential to have toxic effects at even relatively low concentrations in the soil. Managing boron levels in sandy soils (like those of many Florida fields) is particularly challenging. High levels of potassium can also have toxic effects and interfere with the absorption of calcium, leading to reduced pod development and yields. Manganese deficiencies in peanut are associated with high soil pH and are often seen in sandy soils or those where excess lime has been applied.

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Herbicide Injury

Herbicide damage from valor, prowl, paraquat, and dual, as well as from 2,4-DB was reported from South Carolina, and aminopyralid damage was reported in Florida.

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Physiological Issues

Physiological issues, including chimerism and J-root have also been reported from Florida. Plants with J-root have curves in their taproot, and the condition is considered a result of poor seed quality and/or environmental stresses. Chimerism occurs when a single plant contains two types of cells each with different genetic material, usually as a result of mutation.

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Contribute to the collection

If you are an extension specialist, agent or consultant and would like to become involved with the PeanutLink project or submit reports, please contact Dr. Kiersten Fullem or Dr. Nicholas Dufault, of UF/IFAS Plant Pathology.