Irwin County Extension 107 West Fourth Street Ocilla, Georgia 31774-1401

Office Phone: (229) 468-7409 Cell Phone : (229) 424-2863 E-mail: pedwards@uga.edu

Webpage: https://extension.uga.edu/county-offices/irwin.html

IRWIN COUNTY EXTENSION AGRICULTURE NEWS - Vol. 14 Wed. Apr 15, 2020

Phillip Edwards Irwin County Extension Coordinator In this issue: Important Links, Recent, Preemergent Herbicides in Cotton, Corn Wind Damage, Row Crop Disease Update, Thrips Indicator, Planting Conditions Calculator, Row Crop Disease Update, Peanut Inoculant, Potential Seed Quality Issues, Recent

Ambrosia beetle damage in pecan Become an Irwin County 4-H Educator Pond weeds: alligator weed and primrose Important Links UGA Peanut Website find New Peanut Rx Calculator and Current Industry Peanut Rx forms https://peanuts.caes.uga.edu GA Pest Control Handbook https://extension.uga.edu/programs-services/integrated-pest-management/publications/handbooks.html UGA Pecan Blog with updated bud moth information https://site.extension.uga.edu/pecan/ NC State Thrips Infestation Predictor for Cotton (see below) https://climate.ncsu.edu/cottonTIP NC State Cotton Planting Conditions Calculator (see below) http://climate.ncsu.edu/cotton_planting Georgia Automated Environmental Monitoring Network (soil temperature monitoring http://www.georgiaweather.net/

What herbicides do I apply preemerge for Palmer amaranth control in cotton? Dr. Culpepper, UGA Cotton Weed Specialist, preaches that preemergence herbicides are the most effective tool to prevent resistance to post herbicides. Research conducted across GA during 2018/2019 showed that an effective preemergence herbicide mix reduced the number of pigweed needing to be controlled by the first POST or topical spray by 99.8%. Figure 6 below illustrates

the number of emerged Palmer per acre when Reflex, Direx, or Warrant is used along PRE. Please notice the decrease in Palmer emergence when tankmixes are used.

The figure below shows that tankmix combinations for preemerge cotton herbicides for the management of Palmer amaranth.

Corn Wind Damage Bryant I just wanted to provide some thoughts after last night’s and today’s storms across much of south Georgia. Many of you may be getting calls later today and this week or are already getting calls regarding wind damage to corn. The three main problems we want to watch for following severe wind events are greensnap, root lodging, and pinching.

• Greensnap is when the plant breaks at some point along the mainstem. This is most likely to occur in plants that have reached or exceeded the V8 growth stage, but should still be scouted for in younger plants. Most often, plants that have “greensnap” may not recover and potential yield losses may be correlated to the percent stand reduction.

• Root lodging from strong winds is most often found in plants that have surpassed the V13 growth stage and are nearing tassel. The roots on the windward side of the plant will be uprooted/exposed while the roots on the opposite side of the plant will be buckled below the soil surface. While this issue tends to effect more mature/heavier corn plants it should not be completely ruled out in younger corn plants. Past research has shown that root lodged plants can recover vertical growth, through “goosenecking”, without significant yield loss if the damage no later than 10 days prior to tasseling.

• Pinching is similar to greensnap but instead of actually breaking, the mainstem folds, or pinches. Corn plants will remain alive and can recover upright growth but yield loss may occur due to decreased efficiency in nutrient and water flow within the plant.

Overall, most of the corn in the state is young enough that it should recover without significant yield loss concerns. If you do find instances of greensnap, root lodging, or pinching, the grower should carefully consider the percent or stand affected, the original yield goal, value of inputs already applied, and potential yield loss from a later planting date prior to making any replant decisions. If you need anything from me please reach out through email or phone. NC State Thrips Infestation Predictor for Cotton and Plant Date https://climate.ncsu.edu/cottonTIP The location picked was for Ocilla yesterday. A pretty interesting tool to take a look at.

NC State Cotton Planting Conditions Calculator http://climate.ncsu.edu/cotton_planting

Row Crop Disease Update Kemerait One day closer to being back to "normal", whatever "normal" may be now. Thanks to strong efforts from Dr. Joe LaForest with Bugwood and Tracey Vellidis, we now have an automated version of "Peanut Rx 2020" on the UGA Peanut Extension website (see above links). I will be putting the current Industry Peanut Rx programs up there as well. A tremendous "thanks" to Joe for the programming and effort, and to Dr. Barry Tillman for his inspiration as well. More to follow.

1. Much, but not all, of our corn is planted now. Talking with Rome Ethredge yesterday, I recognize that some of our earliest corn is already at the V7 stage and "knee high". Please remember two things for our corn producers. First, now is an excellent time to observe early-season stunting and damage from nematodes. Fields where growth and vigor are suppressed, especially in sandier areas of the fields, could be affected by nematodes. Those areas should be sampled (at some point) this season to determine nematode populations. 2. The V8-V10 growth stages (when corn is generally between knee and chest high) is an important time to consider using a fungicide for management of northern and southern corn leaf blights. I would not automatically "spray" for these diseases; however I would put some "footprints" in the field and check for them. Wet weather, a warm spring, and a susceptible variety could add to a problem with these two diseases. If a grower does initiate a spray for control of early-season foliar diseases, they should insure timeliness, coverage, and choice of a fungicide with a mixed mode of action.

2. Cotton growers have their "fingers on the planting trigger" now. They should remember that this is their one, best chance to fight nematodes, bacterial blight, seedling diseases, and, perhaps, CLRDV (Cotton leafroll dwarf virus). I strongly encourage cotton growers (even as they despair about prices) to consider how they can use resistant varieties in their programs and also how they can use nematicides, seed treatments, and in-furrow fungicides, if need be. (I know, I hear you, "Bob, you sure like to spend our money...."

3. Asian soybean rust continued to ONLY be found in Seminole County on kudzu. We continue to scout. 4. Peanut farmers are soon to put seed in the ground. Remember that the one, best chance for nematode, seedling disease,

and Tomato spotted wilt management occurs at planting. Variety selection, use of a pre-plant or in-furrow nematicide, use of Peanut Rx, use of an in-furrow fungicide, if needed, are all opportunities available at, and only at, planting. Be informed.

When to Use Peanut Inoculant Monfort The use of inoculants is always recommended in fields that have not planted to peanut in 4 years or more. • Although inoculants are not always needed in fields planted to peanut in 3 years or less, it is a good insurance policy to apply inoculants each year. • Inoculants should not cost more than $8 to $10 per acre. • The use of ammonium sulfate or any other nitrogen source as the sole nitrogen source for the plants can be very costly compared to inoculants, roughly $30 + per acre. • The recommendation for ammonium sulfate (60 units N) has been as a rescue treatment only for an inoculant failure. • Do not add any other bio-stimulant or fertilizer product in-furrow with seed. All you need is the seed, inoculant, insecticide, and fungicide!!! Why take the risk?

“Potential Seed Quality issues in 2020 – What can I do to reduce the risk of having stand issues?” Monfort Seed Options • Growers should ask what the Germination % is on every lot they purchase. • If you purchase seed, it should be 75% germination or above. o You could send sample to get germination % from Department of Agriculture if you have time before planting • Farmer saved seed may be in any range. o Please make sure to take a sample and submit to the department of Agriculture to determine germination % before you plant. • You might want to treat with Rancona seed treatment to reduce issues with aspergillus flavus and niger. See Bob Kemerait’s article above. Agronomic Decisions • For Seed of all quality ---- plant at optimal conditions (soil temp over 68 degrees and good moisture). Planting marginal seed in subpar conditions will make the situation worse. • Do not plant seed with marginal seed quality more than 2.5 inches deep. • If you have multiple seed lots and/or numerous totes, use the ones with the best germination earlier in the season when soils are not quite as warm. • Make sure the soil has adequate moisture for germination and emergence. This is not the year to chase soil moisture! • Consider slowing down your planting speed. • Under dry conditions, make sure to irrigate before and after planting. • Use an in-furrow inoculant • Determine if in-furrow fungicide is needed. • Do not add any other bio-stimulant or fertilizer product in-furrow with seed. All you need is the seed, inoculant, insecticide, and fungicide!!! Why take the risk? Seeding Rates • Seed at 85% germination or above: plant at normal rates • High 70’s to low 80’s : increase seeding rate 1-2 seed per foot • Seed below 75% germination the outcome may not be very good if you do everything right. • You have more flexibility with twin row plantings to bump up the seeding rate. With lower germination- increasing seeding rate can be the way to compensate BUT if you stack too many seed on top of one another you can get the opposite result. Placing seeds on top of one another or touching in the furrow can increase the potential for seed rot. • It's best not to go over 8 to 8.5 seeds per foot on twin rows and not over 7.5 seed per foot on single rows. It is hard to plant more than 6 seed per foot with a single row planter with a large editable bean plate. You may need to use a virginia peanut plate. Thank You, God Bless You Phillip Edwards Irwin County Agent

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