Pam Knox mentioned that chances of heavy rain go up slightly as tropical cyclone becomes better organized this up coming week. In her blog post, she mentions that the rainfall that is expected over the next week has increased slightly as the area of low pressure in the western Gulf becomes more organized. The low, now dubbed Investigation 91 (see related post for more on this), has a 70% chance of developing into a named storm over the next week as it moves first south and then north again under the variable steering currents. READ MORE
Rainfall totals over the last two days from the CoCoRaHS website. The monitoring sites usually check rain gauges at the same time every day, which is usually in the morning. At the time of writing this, I had over an inch of rainfall in the rain gauge (9/8/24, at 7pm).
The drought monitor changed this past week when it was released last Thursday, September , 2024. According to the Drought Monitor over 77% of Colquitt County is experiencing abnormally dry conditions. .
It is interesting to see the differences between accumulated precipitation for the month of August for Georgia. If you consider the storm during the first week of August, some parts of Colquitt County received 75 to 125% of normal rainfall.
If you look at rainfall patterns for the rest of the month, after August 7, 2024, Colquitt County is between 10 and 50% of normal for accumulated rainfall.
What about defoliating cotton this week? Dr. Camp Hand mentions that statewide it looks like rain is expected Thursday and Friday (in southwest Georgia looks like we even get some on Wednesday). This will affect our defoliation decisions similarly to what I mentioned in last week’s update – keep in mind rain free periods of all defoliants, particularly thidiazuron, which is 24 hrs (I read somewhere a couple of years ago that mixing thidiazuron with a phosphate – i.e. tribufos (Folex, Def, etc.) – reduces that rain free period to 12 hours). Looks like next week will be better.
Looking like highs are in the 80s on the days we can comfortably knock the leaves off, lows in the 60s. Still would be in the 3-4 oz/acre range on thidiazuron (Dropp/Freefall/Klean-pik, etc.) (could heat back up), comfortable with 10 oz/acre tribufos (Folex/Def) maybe even up to 12 oz, and 32 to 42 oz/acre of ethephon (Prep).
Will there be any peanut maturity clinics this week?
Yes, peanut maturity clinics will held this week at the Colquitt County Extension office. This past week, a few samples came into the Extension office for maturity checks. The maturity for Georgia 06G was running 140-145 days. We need to keep an eye on dryland fields, since we had rain over the weekend.
The clinics will be offered every Tuesday, Wednesday, and Thursday until the end of September from 8:30 a.m. to 10 a.m. at the Colquitt County Extension office.
Taking a good sample is CRUCIAL in determining the proper time to dig, so here is a reminder of how to pull a sample for profiling peanut maturity. A peanut hull scrape maturity check will be as accurate as the sample that you take. Pull or dig up at least 5 to 6 adjacent plants from at least three representative parts of a field that can be dug in on a day. Keep these samples from each area of the field separate. Pick ALL the peanuts off the plants until you get around 200 peanuts (a sample should contain between 180 and 220 peanut pods). Pick the vine clean. If it will be a while before you can bring the sample, then pick off the sample and keep the peanuts in a bucket of water to keep them fresh.
If you would like more information, please contact the Colquitt County Extension office at 229-616-7455.
Lots of good information was shared with growers at the Colquitt County Peanut Maturity and Cotton Defoliation meeting. I keep on getting questions about late season plant bugs. Plant bug populations have been spotty, but when populations are high, then we need to take corrective action. Drop cloths are instrumental in determining plant bug populations. According to Dr. Roberts, plant bugs feed on nickel-to-dime size bolls, which are 10–12 days old. If you exceed threshold which is 3 plant bugs per drop, then treatment is needed. Problem fields could have as many as 12–15 immature plant bugs per shake, per Dr. Roberts.
Dr. Hand discussed DD-60 accumulation in Tifton up until August 27, 2024, for multiple planting dates over the last four years. The slide shows that this year is comparable to 2022, and greater than 2021 and 2023.
Dr. Roberts called this week about a spike in whitefly captures in the sticky traps in Colquitt County. Dr. Roberts has been monitoring numerous sticky traps for whitefly at multiple locations in Colquitt, Tift and Worth counties since 2020. Below is trap data for whitefly at trap 115 in Colquitt County. At this location 1400 were captured this past week. We also seen the same trend when Tanner checked sticky traps on the west side of county. The dry weather helped populations build but hopefully the rain this week with help.
You can look at the map by visiting stopwhitefly.org
I received a call or two about burning corn stalks and what nutrients do you loose in the process. According to the MSU article Burning Stalks – What does it Really Cost? Nearly all nitrogen and at least 75% of sulfur contained in plant residues will be lost upon combustion. These nutrients could be especially beneficial for a wheat crop planted following corn harvest. Although phosphorus and potash are not theoretically lost due to residue combustion, considerable loss will certainly occur from smoke and ash that are not recoverable or recycled into the soil. Some of this occurs during the burn event when ash floats out of your field. Substantial loss may also occur thereafter from wind and rainfall displacing ash from your field. Therefore, if you don’t immediately perform a tillage operation capable of incorporating the ash in the soil, additional nutrients will likely be lost from your field.
Still getting calls about armyworms in both annual and perennial forages. The threshold for foliage feeding caterpillars in forages is 3 caterpillars per square foot that are 1/2 inch or longer. Information from Drs. Buntin, Hudson and Baxter about army worms was featured in a blog post last month. If you use Dimilin (diflubenzuron), remember that this product is an insect growth regulator (IGR). It only affects the worms when they molt the next time, so don’t expect to see them drop dead on the spot.
The winter annual forage and small grain recommendations are out and can be seen here.
The recommendations below identify varieties shown to produce above-average yields when planted within the recommended time period for their species and geographic area. Columns identifying “Early” yield represent forage growth from planting to around March 1, depending on location. “Late” columns represent production from after then until regrowth was of too low quality to justify further harvest. “Season long” columns represent varieties with the highest total season yields, which may be of most interest to those who intend a single end-of-season harvest for hay or ensiling or will be supplementing feed during lower forage growth periods. In 2023, the USDA revised its plant hardiness zones. In the new map, Rome (Limestone Valley region) and Griffin (Piedmont region) are very close to the colder and warmer edges of Zone 8a. For variety recommendation purposes, they are reported separately due to their temperature and soil differences. Plains and Tifton are located in Zones 8b and 9a, respectively, and represent areas sometimes referred to as the upper and lower coastal plain. Of the two, Zone 9a is warmer and more humid, increasing the risk of foliar diseases.
Can I still fertilize my hayfield? According to Dennis Hancock, former UGA Forage Agronomist, bermudagrass varieties such as Alicia, common, and (to some degree) Coastal and Russell, are more day length sensitive and slow down substantially after early Sept. It is unlikely one would see a yield response in those varieties to anything nitrogen management for hay fields this time of year more than 50 lbs/ac after mid-August. Tift 85 is much less day length sensitive and will keep growing well until the first. It remains response to N until daytime temps fail to reach 70 or so, but I wouldn’t add a lot of N to it after mid-Sept. (to minimize risk of winter kill).
Have a great week,
Jeremy M. Kichler
Colquitt County Extension Coordinator
The University of Georgia Cooperative Extension does not endorse or guarantee the performance any products mentioned in this update.