In this issue: Dry weather, tips for whitemold control, peanut irrigation, whiteflies, cotton and peanut marketing update, bermudagrass baleage and vaseygrass control.
It has been an interesting weather week. The US Drought Monitor this week shows that abnormally dry weather conditions area expanding in SW Georgia.
Rainfall amounts across the county ranged from 0.25 to a little over an inch for the period of July 20-26, 2025. The illustration below shows rainfall totals for the last week. The UGA Weather Station at Expo recorded 0.47 for the same period and the evapotranspiration ranged from 0.12 to 0.27 inches a day.
Since it has been so hot the last couple of weeks, I received a question or two about what the highest max temperature was recorded in Moultrie. According to CLI-Mate website, the highest max temperature recorded was 105 degrees on July 21, 1942. In 2022, the temperature reached 103 degrees on June 23.
Peanuts: The biggest challenge this week for peanut growers has been irrigation. A have came across a field or two with low levels of spider mite. Caterpillar pests have been low across the county. Caterpillar pests need to be scouted and treated when thresholds are reached.
Dr. Bob says that timely irrigation and/or rainfall is essential for maximum efficacy of a white mold fungicide. Without rainfall or irrigation, the fungicide tends to get trapped in the dense leaf canopy, and away from the crown of the plant and lower limbs where it is needed for white mold control. Timely rain and irrigation help to distribute the fungicide from the leaves to additional targets.
Key points to remember:
1. Depending on the fungicide, you need between 90 minutes and 8 hours of drying time PRIOR to rain or irrigation to ensure good leaf spot control.
2. If leaves are still wet from morning dew when you spray, you need even longer time to ensure adequate leaf spot control.
3. If using a center pivot, I would likely start the pivot by about 6 hours after application; amounts needed to move the fungicide are anywhere from 0.1 to 0.25 inches. This does not have to be “irrigation”.
4. The sooner the better (after appropriate drying time) for irrigation or rainfall to get a white mold benefit. The benefit diminishes quickly with time. After 48 hours there is no benefit.
5. Non-irrigated fields without rainfall can make white mold control tough. My advice- spray at night when leaves are closed or spray when dew is on the plants (recognizing this could negatively impact leaf spot control.)
According to Dr. Porter, “Once peanuts begin blooming and pegging, they will use roughly 0.2” of water daily for ~20 days. By the middle of July, those early/mid-May planted peanuts can use up to 0.3” of water per day on days that it is hot, windy, with low humidity, so it is important to not get behind on irrigation. It is also important to not let your soil temperature get too high with peanuts pegging as high soil temperatures can burn off pegs. Even though it feels like we are still early in the crop season, peanut will hit peak water usage during July, so do your best not to fall behind and lose yield, especially if we continue to remain in similar weather conditions as we have through the middle of June. I think it is important to note that the soil water holding capacity of most of our sandy loam soils falls in the range of 1.0 inches per foot of soil with 50% of that being plant available. Thus, even with a two foot rooting depth, you will only have 1.0 inches of water available to the crop and that will be utilized in three days at the rate of 0.3 inch usage per day.
Dr. Prostko mentioned this week that the rain-free period for 2,4-DB listed in the peanut section of the 2025 UGA Pest Control Handbook of 1 hour (page 222) is NOT correct. Not sure where I came up with the 1 hour since nothing specific is listed on any label nor is it consistent with other sources? After talking with technical folks at Albaugh, LLC (makers of Butyrac 175 or Butyrac 200), the rain-free period for 2,4-DB should be 6 hours.
I have received a few questions about controlling Florida Beggarweed in peanut. Dr Prostko mentions that when I first got to GA in 1999, Florida beggarweed was the #1 peanut weed. It became less troublesome when Valor (flumioxazin) was registered in 2001 (very effective) and when Palmer amaranth exploded. Florida beggarweed tends to be a later emerging weed and prospers during wetter conditions.
At this point in the growing season, there are not many good options for controlling Florida beggarweed in peanut. The first option is a POST (60 days after peanut emergence) application of Classic (chlorimuron). The other option is to use Gramoxone (paraquat) in a non-selective applicator (wiper, sponge, rope-wick). Both of these options are described on page 224 of the 2025 UGA Pest Control Handbook and/or listed below. Please carefully read the comment sections of these recommendations. Peanut cultivar tolerance to Classic is a major concern. If a newer peanut cultivar is not listed in the comment section (i.e. Arnie, TifNV-HG, etc.), that means I DO NOT have any tolerance data and have no clue what will happen.
Cotton: Whitefly captures have increased this week in sticky cards across the county. Dr. Roberts sends out a crew each week to monitor traps and Tanner Wilson also monitors traps in Colquitt County. Plant bug reports have seem to decrease as the crop moves through the bloom stage of development
I was in an agent training the other day discussing the current cotton and peanut marketing situation. Dr. Liu, UGA Cotton and Peanut Economist educated us on the subject. If you would like the information it is available below.
Corn: The corn crop is reaching black layer in numerous fields across the county. I have received a question or two about harvest aid applications for corn. Dr. Eric Prostko, a UGA Weed scientist, says that his usual recommendation is to apply a combination of Roundup and Aim. The PHI for glyphosate and Aim is 7 and 3 days, respectively, according to the Pest Control Handbook. This treatment will not miraculously remove the running morningglory plants, but it will desiccate them enough to facilitate harvesting (i.e., make the vines more brittle and less likely to wrap). For more specifics, please go to the 2025 UGA Pest Control Handbook.
Forages: I had several questions about bermudagrass baleage last week. Dr. Hancock, former UGA Forage Agronomist, had several points to think about on this subject. Struggling to Harvest Bermudagrass? Is Baleage an Option?
Is there control of vaseygrass? A week never goes by without a question about vaseygrass. According to Dr. Lisa Baxter, vaseygrass requires an integrated weed management approach for long term control. Regular mowing of vaseygrass before seed maturity can deplete root carbohydrate reserves and limit the spread of the weed by reducing seed spread. However, herbicides will be required for long-term control. Fall herbicide applications are often more effective than spring treatments for long-term control of vaseygrass. These applications should occur in late August or September when vaseygrass begins allocating carbohydrates from leaves to roots. During this period, the herbicide will be more effectively moved to below-ground plant parts and control should be improved. Dry weather will limit the effectiveness of the fall herbicide applications. Spring treatments can provide temporary control, but regrowth from roots is very common.
Preemergence (PRE) herbicides are not currently labelled for control of vaseygrass, but research is ongoing. These products will control annual grass weeds and remove competition from the vaseygrass, causing the weed to spread. Unfortunately, post-emergent (POST) herbicide options are limited for the control of vaseygrass.
There are no selective control options in bahiagrass (Paspalum notatum) or tall fescue (Lolium arundinaceum) forages, so spot-treatment is required. Glyphosate is a non-selective herbicide and cannot be applied to desirable grasses without severe injury. Glyphosate will translocate or move within any plant that encounters the herbicide. Use caution to avoid injury to non-target forage species. Wick-bar, or roller weed-wiper, applications of glyphosate are possible. University of Florida researchers recommend mowing the field and following 30 days later with the weed wiper (Sellers, 2019). For best results, use a 10% v/v glyphosate solution (12.8 fluid ounces per gallon) and wipe the mixture in two directions. Spot-treatments should be made with a labelled rate of glyphosate. There are many different formulations of glyphosate and actual rates will depend on the product used. Please refer to the herbicide label for mixing instructions.
Vaseygrass responds to applications of Pastora (metsulfuron and nicosulfuron) or Impose (imazapic). These products are only labelled for use in bermudagrass. Both products are only rated as providing fair control and may only provide suppression of the vaseygrass by reducing the population or plant vigor.
Pastora should be applied in a broadcast application with a boom sprayer at 1.25 to 1.5 ounces per acre. Spot-treatments of Pastora can be made by mixing 2.5 ounces of chemical with 25 gallons of water. This solution should be used to treat no less than 1 acre.
Applications should be made when the vaseygrass is 6 to 8 inches tall. This usually occurs approximately 7 to 14 days after a grazing or harvest event depending on rainfall amount.
The maximum application rate of Pastora is 2.5 ounces per acre per year.
Impose should be applied in a broadcast application with a boom sprayer at 6 to 8 fluid ounces per acre. Spot-treatments of Impose can be made by mixing 1% solution (0.2 fluid ounces) of chemical and 1% methylated seed oil (MSO; 0.2 fluid ounces) per gallon of water. All applications should be made when the vaseygrass is 4 to 8 inches tall. This usually occurs approximately 7days after a grazing or harvest event depending on rainfall amount. The maximum application rate of Impose is 12 ounces per acre per year.
Bermudagrass injury or stunting is expected with both Pastora and Impose. Pastora will delay the next harvest by 7 days and Impose will delay by 21 days. This delay caused by the Impose application will generally lead to at least one lost harvest in the season of application. Do not apply either herbicide during the transition period, from dormancy until 100% green-up. Follow all label instructions to avoid additional injury to the bermudagrass stand.
Multiple herbicide applications will be required to improve control of vaseygrass. Do not exceed the maximum annual rate of the herbicides per application or year. Improved cultural management of the pasture or hayfield can also improve suppression of vaseygrass and other weed species. Improved management practices to consider are:
- Correct nutrient deficiencies in the soil following soil sample recommendations
- Correct soil pH following soil sample recommendations
- Increase grazing or harvest height to 3 inches for bermudagrass, 3 inches for bahiagrass, and 4 inches for tall fescue
- Minimize soil disturbance by discontinuing vertical tillage or aeration
Improve soil drainage by clearing drainage ditches or installing drainage systems
Pecans: I’ve Been Spraying, So Why Do I Have Scab?
Have a safe week and if you have questions please call the office,
Jeremy M. Kichler
Colquitt County Extension Coordinator
The University of Georgia Cooperative Extension does not endorse or guarantee the performance of any products mentioned in this update.