Another exciting week in Colquitt County agriculture.
The 2023 Sunbelt Ag Expo Field Day is scheduled for July 20, and farmers are invited to join us to learn practical information from the region’s top agricultural scientists about the newest technologies that farmers can use to improve their operations.
The Sunbelt team looks forward to welcoming farmers and professionals in the ag industry to a Driving Tour of the Darrell Williams Research Farm. The half-day event will take place at the 600-acre Darrell Williams Research Farm, located at the Expo show site at Spence Field in Moultrie, Ga. Registration is free for anyone who works in agriculture. Visitors should arrive thru Gate 2 anytime between 8:00 am and 9:00 am to begin the tour. Directional signs will direct those in attendance to a red tent where they will register, receive a welcome bag including snacks, register for CCA credits, and begin the tour. They will never have to step out of their vehicle for this process. Once registered, visitors will then drive-thru the tour path while viewing pre-recorded segments featuring university researchers and company vendors. In addition, farmers can choose to pull aside at stops that particularly spark their interest to further investigate plots and visit one-on-one with the researchers.
Peanuts: Peanuts around the county are starting to green up and grow. A few reports of low levels of foliage feeding caterpillars in some fields. The threshold is 4 to 8 foliage feeding caterpillars per foot of row. Use lower threshold range when vines are small and/or stressed. Spraying when caterpillars are below economic thresholds is a waste of money.
I had a question or two about applying Dimilin in peanut insect programs. According to Mark Abney, we would rather scout fields and treat at threshold, Dimilin has long residual activity and does not flair secondary pests. Dimilin is really good for managing velvetbean caterpillars, but you will still need to scout for other species like the soybean looper, which is not controlled.
I am seeing a hit or two of white mold in earlier-planted peanuts. Rain over the last few days is going to make fungicide applications a challenge. Dr. Bob Kemerait thinks that the combination of warm daytime and nighttime temperatures is a good environment for white mold. He says white mold is smoldering on peanuts and is about to ignite. It was 74F at 4:45 AM this morning in T-town. Warm nighttime temps, especially warm nighttime temps, plus hot daytime temperatures are going to bring white mold in Georgia peanuts to a roaring blaze. Time fungicide applications to capture irrigation or rainfall within 8 to 24 hours following application.
Recognize that no fungicide program will eliminate individual “hits” of white mold but an effective fungicide program must stop white mold from spreading. An effective white mold program includes a) choice and rate of product, b) timing of application, and c) timing of irrigation or rainfall following the fungicide application. According to Dr. Kemerait, tebuconazole is cheap and can be effective against white mold, but it is not at good, sometimes not nearly as good as our newer (more expensive) white mold fungicides.
How much boron do I need for peanuts? For peanuts, 0.5 lb B/A is recommended, preferably split in 2 applications of 0.25 lb B/a each with early fungicide sprays. It takes 1.25 lb/a Solubor to get 0.25 lb B/a and 1 quart (32 oz) of 10 % Liquid Boron to get 0.25 lb B/a. Also beware of products recommended at very low rates. For example, 6 oz of a 5 % liquid boron only gives you 0.025 lb B/a.
Excessive foliar boron may be toxic to peanuts so do not exceed 0.5 lb B/a for a seasonal total
What about applying manganese in peanut? A tissue sample is a great way to detect manganese deficiency in peanuts. Manganese deficiencies may occur on sandy soils with a pH greater than 6.3. If Mn deficiency occurs, apply a broadcast spray of Mn using 1/2 pound Mn per acre as manganese sulfate or 0.15 to 0.25 pound Mn per acre as chelated Mn in 20 gallons of water per acre. If symptoms persist, the spray should be repeated at 2 week intervals.
The last two editions of “All about the Pod” is available.
In one of the episodes of All About the Pod, Dr. Monfort talks about UGA on farm peanut trials that numerous county agent conduct in their counties. We have two in Colquitt County. At these locations we are comparing varieties such as Georgia 06G, AUNPL-17, GA-16HO, FloRun 331, GA-21GR, GA-18RU, GA-22MPR, and FlorRun T-61. If you are interested in looking at one of the locations let me know.
Cotton: Cotton in the area ranges from squaring to 3rd week of bloom. Low levels of whitefly were reported in the east part of the county. The boll injury threshold for stink bugs should be adjusted up or down based on the number of susceptible bolls present. Use a 10-15% boll injury threshold during weeks 3-5 of bloom (numerous susceptible bolls present), 20% during weeks 2 and 6, and 30% (+) during weeks 7(+) of bloom (fewer susceptible bolls present). If Silverleaf whitefly (SLWF) is present in field do not use Bidrin for stinkbug control. If you have SLWF and/or spidermites use Bifenthrin.
Dr. Steve Brown, Alabama Extension Cotton Agronomist, wrote an interesting article about PGR management in cotton.
PGR Management. We had a recent in-field grower meeting which rightly focused on plant bugs, but the issue of PGRs was also a frequent topic of discussion … and perplexity. Yes, each year is different and thus requires in-season adjustment according to weather and crop conditions.
Information on PGR use can be found in the formal publication, How to Think about Cotton: Plant Growth Regulators and in a recent Cotton Specialists Corner Podcast, Thinking about PGRs — Differences and Similarities across the US Cotton Belt.
Making good decisions involves assessing Current and Near-Term Conditions. The questions below help tilt management towards being more aggressive, less so or passive altogether. Brown
Current Assessment
- Variety – aggressive or not?
- Crop growth stage, conditions?
- Field conditions – What is the fertility and growth history?
- NAWF at early bloom? If 8-9, be aggressive; if 4 or 5, wait
- Current internode lengths between 4-5thleaf down from the terminal? If 3 inches or more, apply or consider being more aggressive.
- Calendar date? For late crop, tend towards an aggressive approach if favorable growing conditions exist
- Is the field Irrigated or dryland? What is the recent rainfall patterns for your area?
Pending Weather Forecast
- Good to excellent rainfall, moderate temperatures (highs <90oF) — be aggressive unless growth is well in check
- High temperatures, little to no rain expected, minimal or no irrigation – be conservative or passive
What about layby options for cotton? I am glad you asked. A number of herbicide combinations are available for directed application to any variety of cotton. More common options include Caparol + MSMA, Cotoran + MSMA, diuron + MSMA, Fierce + MSMA, and Valor + MSMA. Aim, Dual Magnum, Envoke, ET, Outlook, Staple, Warrant, and Zidua may be added to some (not all) of these combinations; follow the most restrictive requirements for products in tank mixtures for application timings, cotton stage of growth, etc.
The postemergence-directed herbicides listed above are primarily for annual broadleaf weeds and nutsedge. MSMA in these mixtures will control annual grasses less than 1”. Except for Aim, ET, and MSMA, the options listed above will also provide some residual control of sensitive weeds.
Diuron + MSMA has many strengths and is the most commonly used of these options. The mixture really only has two weed control weaknesses. First, it lacks control of larger (>4”) morningglory. When both Palmer amaranth and morningglory need to be controlled then one should consider including Envoke with the diuron + MSMA; Envoke will also improve nutsedge control. Second, Diuron + MSMA lacks control of grasses larger than 1 inch. If Palmer amaranth is not problematic but grasses larger than 0.5” are an issue, Roundup mixtures in tolerant cotton will be more effective.
Corn: The area corn crop ranges from dough to 3/4 milk line. As of July 17, 2023, no southern rust has been confirmed in Colquitt County. Below is an example of Southern Corn leaf blight from a field in Colquitt County. Usually, this is more of a curiosity than anything else.
Below is an example of what Dr. Bob calls an “abiotic condition”. I am finding this in about every corn field in the county and this looks much like rust, but isn’t. Wipe a leaf with southern rust on something white and you will end up with an orange smear of spores. You won’t get a smear from this which, for now, we are calling an “abiotic condition”.
If you have questions please contact you local county Extension agent.
Have a great week.
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.