Skip to Content

Bermuda Grass Stem Maggot

Published on 08/06/19

Drought changes management strategy for Bermuda grass stem maggot

By Clint Thompson for CAES News

Drought-like conditions this summer are forcing Georgia forage farmers to delay treatments for Bermuda grass stem maggot, according to Lisa Baxter, University of Georgia Cooperative Extension forage specialist.

It is normally recommended that farmers wait seven to 10 days after harvest, then apply a pyrethroid insecticide labeled for forages at the recommended rate, then repeat treatment seven to 10 days later.

A lack of rain across the state this summer calls for that treatment timeline to be tweaked, Baxter said.

“The problem is that, in a drought, we don’t have green leaves seven days after harvest. If there aren’t green leaves, there are no adult flies out there and that is what the pyrethroid is killing — the adult flies — not the other stages of the stem maggot,” she said.

For this reason, Baxter is recommending that Georgia forage producers hold off on the first treatment if they are experiencing below normal rainfall.

“It feels good to put out the chemical like it says to on the calendar, but if the grass doesn’t match that, we’ve got to wait,” she said.

Most producers harvest on a 28-day interval, while some try to stretch their harvest window to 35 days to attempt to harvest more hay, although the quality may drop, Baxter said.

According to the U.S. Drought Monitor, parts of Georgia are experiencing abnormally dry conditions, especially in middle Georgia around Houston County. Little rainfall equates to slow growth for forages, especially if they’re not being irrigated.

“The way the damage happens, the fly has to lay its egg on a leaf. When the egg hatches, the larvae go into the stem and chew around in there, which is what kills the top (of the plant). If there are no green leaves for flies to lay eggs on, the whole life cycle stops,” Baxter said.

Baxter has delayed some research trials and Extension demonstrations on lightly irrigated plots because there wasn’t enough growth to treat with insecticide.

Bermuda grass stem maggot was first discovered in southern Georgia in 2010 and is a persistent problem for hay producers. Baxter said that the pest appeared earlier this year because of unseasonably warm temperatures. The pest damages Bermuda grass hayfields and pastures throughout the Southeast U.S. and is regularly seen throughout the Coastal Plain region up to Macon.

“(The pest) kills the top two leaves of the plant. Once it damages the top, we don’t get any more upright growth out of the plant and it really hurts our yield. We can see as much as 80% yield loss if we’re not careful,” Baxter said. “It’ll look like you’ve frosted the top of your hayfield because of the dead stems at the top.”

For up to date information about Georgia’s climate conditions, see UGA agricultural climatologist Pam Knox’s blog, Climate and Agriculture in the Southeast.

Clint Thompson is a news editor with the University of Georgia College of Agricultural and Environmental Sciences based in Tifton.

Dieback of Pecan Branches

Published on 07/19/19

UGA Extension pecan specialist cautions growers about dieback of pecan branches

By Clint Thompson for CAES News

Nearly a year after thousands of trees were destroyed by Hurricane Michael, Georgia pecan producers are reporting the dieback of pecan branches and leaf burning in trees that survived the October 2018 storm, according to Lenny Wells, University of Georgia Cooperative Extension pecan specialist.

The conditions, which are occurring in trees ranging from 2 to 15 years old, are not uncommon following storms that feature high winds, Wells said, attributing the problems to delayed hurricane damage.

“The trees got knocked around so much in that storm, even if it didn’t blow them down, it shook them around enough that it broke some of those roots underground and they haven’t been able to regrow enough roots yet to support the growth that the tree is trying to make,” Wells said.

Now that the temperatures have risen and the water demand has gone up, those trees are basically “in shock,” Wells said, and don’t have the roots they need to support them.

Wells says growers whose trees are showing these symptoms need to improve the root to shoot ratio and keep the roots watered.

“Growers need to cut some of the tree back and try to get the top of the tree back in line with what the roots can support,” he said. “The more severe the dieback, the more you need to cut the tree back. The worst trees may need to be cut back by half if the cambium is still green under the bark.”

Wells has seen similar symptoms in older trees that were pushed down by high winds but stood back up and righted after the storm by farmers. When the trees were erected, the roots were broken on the other side of the tree. These trees had enough root to survive initially, but the combination of intense summer heat and high water demand led to their demise, he said.

Scab disease

Wells has also fielded his share of calls regarding scab, a fungal disease that infects the leaves or nuts of pecan trees. If it hits early enough, scab can cause the pecan nuts to blacken and fall from the tree.

After a late dry spell in May, Georgia has received adequate rainfall in June and July, which has increased instances of scab disease in some orchards.

“It’s pretty rough so far this year. We’re seeing it on ‘Desirable’ and ‘Pawnee’. We’re starting to see it on some varieties we haven’t seen as much in years past, like ‘Stuart’,” Wells said. “The rain has certainly given us a lot of disease pressure and we’re at the point in the season where, if growers do have a crop, they can’t let up at all on those varieties that are susceptible.”

Wells recommends growers space their spray treatments 10 days apart.

For up-to-date information about Georgia’s pecan industry, see site.extension.uga.edu/pecan.

Clint Thompson is a news editor with the University of Georgia College of Agricultural and Environmental Sciences based in Tifton.

Control of Cowpeas

Cowpea Control (Prostko)

Every so often, I get a few inquiries about herbicides for the control of cowpea (Vigna unguiculata) (Figure 1). Unfortunately, cowpea (also known southern pea, black-eye pea, or crowder pea) can be a very difficult plant to control and not much research data is out there.  In preparing our UGA Weed Science graduate students for the upcoming 2019 National Weed Science Contest, I was able to collect some good data for various herbicides (Table 1).

In summary, the following herbicides could be used for the control of cowpea depending upon the planted crop:  PRE = Atrazine, Balance Flex (isoxaflutole), and Tricor (metribuzin); POST = Classic (chlorimuron), Engenia (dicamba), Enlist One (2,4-D), Envoke (trifloxysulfruon), Gramoxone (paraquat), Liberty (glufosinate), Osprey (mesosulfuron), Roundup (glyphosate), Sharpen (saflufenacil), and Stinger (clopyralid).

Figure 1.  Cowpea

Table 1.  Cowpea (‘Top Pick Pinkeye Purple’) control with PRE and POST herbicides, TyTy, Georgia, 2019.1

Herbicide Rate/A

(oz)

Application Method

(PRE or POST)

Test 1

Control (%)

Test 2

Control (%)

15 DAT3

(Prostko)

20 DAT

(Culpepper)

14 DAT

(Prostko)

Harness 7EC 22 PRE 0 0 0
Atrazine 4L 64 PRE 100 100 100
Diuron 4L 26 PRE 0 0 0
Valor SX 51WG 3 PRE 0 10 20
Pursuit 2SL 4 PRE 0 8 0
Balance Flexx 2SC 6 PRE 100 100 100
Callisto 4SC 3 PRE 60 65 0
Prowl H20 3.8ASC 48 PRE 0 5 0
Zidua 85WG 1 PRE 0 10 0
Dual Magnum 7.62EC 21 PRE 0 12 0
Spartan 4L 1 PRE 0 0 0
Tricor 4L 24 PRE 100 100 100
Enlist One 3.8SL 13 POST 95 95 100
Buctril 4EC 12 POST 50 70 30
Classic 25DG + COC4 0.5 POST 95 95 85
Select Max 0.97SC + NIS 25 POST 0 10 0
Stinger 3SL 8 POST 95 100 80
Engenia 5SL 6.4 POST 95 95 85
Fusilade DX 2EC + COC 12 POST 0 10 0
Resource 0.86EC + COC 4 POST 0 0 0
Reflex 2SL + NIS 12 POST 50 50 50
Liberty 2.34SL +

N-Pak AMS (2% v/v)

22 POST 100 93 85
Sandea 75DG + NIS 0.66 POST 40 25 30
Osprey 4.5DG + MSO 4.6 POST 70 88 85
Accent 75DG + COC 0.66 POST 65 75 60
Gramoxone 2SL + NIS 32 POST 100 95 90
Facet 75DG + MSO 16 POST 50 60 55
Sharpen 2.85SC + MSO 2.5 POST 95 92 80
Laudis 3.5SC + MSO 3.5 POST 65 68 60
Envoke 75DG + NIS 0.09 POST 85 88 90
Roundup PowerMax 5.5SL 22 POST 100 97 90

1Test 1: Planting Date = May 28; PRE = May 29; POST = June 13 (~8” tall cowpea).

2Test 2: Planting Date = June 17; PRE = June 18; POST = July 8 (~8” tall cowpea).

3DAT = days after POST treatment.

4COC = Agridex @ 1% v/v; NIS = Induce @ 0.25% v/v; MSO = MES 100 @ 1% v/v.

Sunbelt Expo Field Day

By Clint Thompson for CAES News

Georgia farmers can learn about agricultural research while interacting with University of Georgia scientists during the annual Sunbelt Field Day in Moultrie, Georgia, on Thursday, July 25.

From 8:30 a.m. to noon, UGA agriculture specialists and other industry leaders will present their findings from various crop research projects conducted on the 600-acre farm.

Among the UGA experts whose research will be highlighted is UGA Cooperative Extension soils and hydrology specialist Glen Harris. He’s researched cotton and peanuts at Sunbelt for more than 20 years and believes the research done here is vital to the Georgia farming community.

“My research experience at the Sunbelt Ag Expo goes back to the days of Darrell Williams, who the research farm is named after,” Harris said. “It’s a place to be able to show the cutting-edge research that the University of Georgia is known for.”

Harris’ research this year focuses on soil nutrient needs on cotton, specifically how fertilizer impacts cotton’s growth. Sulfur-based fertilizer, foliar potassium and side-dress nitrogen fertilizer are part of his research, which is replicated every year.

Cotton, peanut, weed, vegetable and forage researchers will speak to field day attendees about the statewide impact of their research. Along with Harris, other UGA scientists presenting this year include Lisa Baxter, UGA Extension forage agronomist; Stanley Culpepper, UGA Extension weed specialist; Dennis Hancock, UGA Extension forage specialist; Jeremy Kichler, Colquitt County Extension coordinator; Monique Leclerc, Regent’s Professor on the UGA Griffin campus; Scott Monfort, UGA Extension peanut specialist; and Jared Whitaker, UGA Extension cotton specialist.

“The research partnership that we have with the UGA College of Agricultural and Environmental Sciences researchers gives us a healthy blend of university and corporate research plots on our Darrell Williams Research Farm at the Sunbelt Ag Expo. Working with the UGA researchers, we are able to stay on the cutting edge of the latest agronomic research as it pertains to seed and forage varieties, crop protection, irrigation and water management, soil fertility, and precision agriculture,” said Chip Blalock, executive director of the Sunbelt Ag Expo.

For more information about the Sunbelt Field Day, see https://sunbeltexpo.com.

Clint Thompson is a news editor with the University of Georgia College of Agricultural and Environmental Sciences based in Tifton.

Two Weaning Methods

Jason Duggin, PC Southeast Update, July 2019

 

One of my dad’s favorite sayings was, “There’s more than one way to skin a cat.” When it comes to types of calf weaning methods, this phrase could easily be used.  However, my dad tended to tell me this when I was using the wrong method.  In the South, operations are often times limited in terms of space, pens, and sufficient fencing to hold curious calves.  Thus, weaning in the Southeast can be a challenge.

 

For demonstration purposes, let’s look at 2 weaning types.  Option 1: Gather the calves, load them on the trailer and ship them to the closest market or buyer.  If your jaw just dropped out of your mouth, I don’t blame you.  I’m not suggesting this is a good strategy, but it is a method that is commonly used.  This is the old standard from days gone by, but some cattle are still managed this way. What’s the cost of using this method? Well, the biggest cost is not being able to capitalize on selling a “weaned” product.  Weaned calves are worth $20 to $40 more per head.  You might ask, “Why are Option 1 calves cheaper?” This is an important question to consider.  To ask it another way, who wants to buy bawling calves?  It’s certainly not the feedlots. Those are train wreck scenarios riddled with respiratory breakouts and increased death loss.  The answer: Those looking to cash in on the cheapest calves on the market.  These buyers are willing to take on the risk of a highly stressed calf at a cheap price in hopes of “straightening” them out health wise, and then over the course of a couple of months, selling them at heavier weights.

 

So, what method is better than option 1?  Just about anything!  Now let’s consider another option which can consist of weaning with nose to nose contact between calf and dam.  This is ideal for reducing calf stress, bawling, and sickness.  After a typical 45- or 60-days preconditioning period, these calves will have an advantage at the market.  They should also gain another 2.0 lbs. per day, conservatively.  Combine that with a good deworming protocol, and there can be some serious payweight added to your sale ticket.    Good weaning management is important and includes- abundant, clean water; quality forage; a good growing diet; good shade; secure fencing; sanitary pen conditions.  It’s not the only way, but it’s the best way.

Row Crop Disease Update

Corn:  Southern corn rust is now confirmed in 7 adjoining fields in Baker County.  I don’t think it is a coincidence that we are finding it now; development is following the rain periods of recent weeks.  I expect (stay tuned) to have more identified very soon.  Bottom line:  I think that the amount of southern rust is fairly low in the state right now, but that could change fairly quickly.  Wind and more wind yesterday and rains certainly were PERFECT for moving spores.

 Recommendation:  Any corn in the dough/dent stage as of now, i would likely not advise spraying for rust in SW Georgia, or anywhere else.  Corn in  late milk stage, I would likely not spray either, because, again, the amount of rust is low.  Any corn in SW Georgia that is at early milk, silking or tasseling stages in SW Georgia, I would certainly think about protecting with a fungicide.

 IF YOU THINK YOU FIND SOUTHERN RUST, PLEASE LET US KNOW

 Peanuts:  We are in a combat situation I believe now with white mold.  I am getting pictures of young plants that are affected.  Very warm soil temperatures followed by moisture followed now by hot temperatures creates PERFECT white mold conditions (southern stem rot, Nickie).  Typing this at 7:30 AM, it is already 79 degrees and 100% humidity.  I can almost hear the white mold…..

 Recommendations:  Now is not the time to be timid on white mold control.  The weather is here, teh crop is developing, protect the crop with fungicides from leaf spot and white mold.

 Cotton:  No target spot or areolate mildew, but conditions are favorable.  Please advise your growers to pay attention and scout.  FIRST BLOOM is an important time to check your crop for target spot.  Even if you don’t spray, be aware.  Also, keep your eyes open for reddened, stunted, distorted plants that COULD be our new viral disease.  If you find plants like that, please let me know so we can check them out.

 Soybeans:  Asian soybean rust is present in kudzu across the Coastal Plain.  Conditions (windy and passing storms) are PERFECT for moving it to soybeans.  IF THEY WERE MY BEANS, I WOULD DEFINITELY APPLY A FUNGICIDE BY R3, POD SET STAGE, especially if I was putting out dimilin and boron, and even if I wasn’t.  GOOD INSURANCE.

By  Bob Kemerait 

Slippery Algae in Turfgrass

Published on 06/13/19

Rain, overwatering can cause slippery algae to pop up in turfgrass lawns

By Clint Waltz for CAES News

Recent dry weather encouraged the use, and possible overuse, of irrigation systems. Followed by tropical conditions characterized by heavy rainfall and humidity, there have been reports of a jelly-like substance growing in turf.

The jelly-like matter is Nostoc, a genus of cyanobacterium formerly classified as blue-green algae. The algae — commonly known as star jelly and witch’s butter, among other names — may appear suddenly in lawns and other turf areas in warm temperatures following a period of rain, and the algae can also be an indication of overwatering.

In turf, Nostoc generally emerges on a site where the grass is growing poorly due to severe compaction, overwatering or both. It does not cause the turf to decline or die, but it does colonize areas where it has favorable growing conditions and the grass was already thin.

Poor drainage and compacted soils create a favorable environment for Nostoc. It dries out when moisture or rainfall diminishes, but it has only gone into dormancy. With enough moisture, it will come back to “life.”

In its hydrated, gelatinous, green state, it can be a safety hazard because it’s slippery — so be careful walking on it.

However, when it dries out, it can restrict turfgrass growth. Nostoc dries into a black crust that can prevent stolons from rooting, or “tacking,” into the soil. This delays the growth and spread of turfgrass.

Nostoc can be difficult to control. To discourage its growth, encourage the growth of the grass. Algae is less of an issue with an actively growing turfgrass canopy.

The first step is to check the irrigation system to make sure it is watering properly (i.e., not too often or too much). The turfgrass species grown in Georgia perform better when grown on the slightly dry side, so scaling back irrigation and adjusting the irrigation schedule will benefit the grass and can discourage algae.

The second step is to improve the internal soil and surface drainage. Core aeration opens the soil, allows oxygen into the root system and reduces compaction.

Allow the soil surface to dry out, then break up the Nostoc “crust” by cutting the upper ¼- to ½-inch. Breaking the algae into pieces will encourage it to spread. This also permits the turfgrass stolons to root into thin areas and outcompete the Nostoc.

With proper irrigation and core aerification, the grass can cover, and eventually predominate, the area where the Nostoc was present.

For more information about turfgrass in Georgia, go to www.GeorgiaTurf.com.

Clint Waltz is a Cooperative Extension turf specialist with the University of Georgia College of Agricultural and Environmental Sciences.

Sunscalding on Fruits and Vegetables

Published on 06/14/19

High temperatures, few clouds lead to sunscalding concerns for Georgia producers

By Clint Thompson for CAES News

Even with the welcomed rain Georgia farmers experienced this week, sunscalding on certain fruits and vegetables remains a concern as producers continue with this year’s harvest, according to University of Georgia Cooperative Extension vegetable specialist Andre da Silva.

When temperatures are high and the sun is able to shine for weeks at a time with very little cloud cover, which had been the case in mid-to-late May, certain crops are vulnerable to developing sunburnt conditions — notably watermelons, tomatoes and bell peppers.

“The sun has definitely been too aggressive for some of our vegetable crops, especially with bell pepper, tomato, and watermelon. Growers have been asking for products to protect their crop from the sun,” da Silva said. “Unfortunately, there is not much research on this topic for us to make a recommendation. However, the first UGA research trial is being conducted this season.”

Watermelons are most susceptible to sun damage if they endure a prolonged dry period. Without moisture, the vines will begin to wilt and the fruit will be more exposed to the sun. When watermelons burn, the rind will appear yellow, rendering the crop unmarketable.

“Growers that need to exercise the most precaution are the watermelon growers who are using plastic mulch with overhead water application. If they haven’t been applying enough water, they will see their plants shrink. It’s hard for the root systems of those plants to get the water that the growers are applying,” da Silva said.

If watermelon producers can protect their crop from the sun, they’ll extend their harvest window into late June and around July 4 when watermelons are at peak demand and prices for farmers are at their best.

“We don’t expect temperatures to get this hot, this early,” da Silva said. “We need a little bit of rain every day with a little bit more clouds to avoid future sunburning, and then we’ll have good soil moisture.”

Prior to the June 8 weekend, the last substantial rainfall in south Georgia was during the weekend of May 11. According to the United States Drought Monitor, (www.droughtmonitor.unl.edu) drought conditions are considered moderate, though da Silva believes they’re still likely much worse. Along with fellow UGA vegetable scientists Bhabesh Dutta and Stormy Sparks, da Silva has traveled across south Georgia to survey the damage inflicted by the weekslong drought.

“If growers hadn’t been pumping up their irrigation this spring, they could very easily lose their crop this year,” da Silva said.

Direct contact of fruit to sunlight can cause blossom end rot disorders. Previous research trials from da Silva and colleague Tim Coolong on the UGA Tifton campus showed that fertilizer strategy, mainly those consisting of calcium nitrate, is key to reducing blossom end rot, a calcium-related disorder that affects mostly peppers and tomatoes.

For up to date information about weather events in Georgia, see the UGA Weather Network website at www.georgiaweather.net.

Clint Thompson is a news editor with the University of Georgia College of Agricultural and Environmental Sciences based in Tifton.

App Helps Fruit Growers

Published on 06/18/19

App helps fruit growers in Eastern U.S. diagnose disease and insect problems

By Denise M Hatcher for CAES News

Walking through his peach orchard, a farmer notices something he has not seen before on the leaves of a few trees. He quickly pulls out his cell phone and accesses the MyIPM smartphone app.

Through a series of descriptions, audio and images, the free mobile app and tool can help users diagnose crop diseases, insect pests and disorders of fruit crops grown in the Eastern U.S., including apple, blackberry, blueberry, bunch grape, cherry, cranberry, peach, pear and strawberry.

The app was first developed by plant pathologists at Clemson University to give growers a “one-stop shop” to access all of the resources they might need for disease management, says Brett Blaauw, an assistant professor and peach specialist with the University of Georgia Department of Entomology. A couple of years later, two more apps were created: one focused on insect pests and another geared specifically for the Northeastern region of the U.S.

“When I came to UGA, I worked on merging the three separate apps into one master app, which included new tools, crops and functionality,” Blaauw said. “The single MyIPM app currently has nine crops with disease diagnostic tools and six crops for insect diagnostic tools.”

To date, the app has been downloaded more than 2,100 times. Designed to promote integrated pest management in commercial fruit crop production, one of Blaauw’s favorite aspects of the app is that it’s full of useful information for users of both Apple iOS and Android mobile operating systems.

“Not only is there a large list of chemistries that are labeled for each disease or insect pest, but users also have the ability to view high-resolution pictures to identify symptoms and signs of disease and insect injury,” he said. “With that said, my real favorite aspect is that the app is free.”

The app is continually being updated by leading Extension specialists at seven land-grant universities and the Southern IPM Center.

Feedback from users has been overwhelmingly positive. Of the users surveyed, 65% say that the app has helped them manage pests and 70% say that it has increased their knowledge of pests and IPM, according to Blaauw.

“Nearly everyone I talk to about the app is pleased with its functionality and ease of use,” he said.

The app has been downloaded to more than 70 different countries, including India, Mexico and Canada.

Blaauw is currently working on adding a section on beneficial insects to help growers identify “good bugs” using the app. He hopes to see the app expanded to include more crops.

For more information on the MyIPM app, visit https://apps.bugwood.org/apps/myipmseries/.

Michele Hatcher is the editor of the Hexapod Herald, the newsletter of the University of Georgia Department of Entomology.

Bermudagrass Stem Maggot in Hayfields

By Will Hudson, Lisa Baxter and Dennis Hancock

We’ve had a number of calls from growers and agents in the last week or so concerned that they should be spraying for BSM.  Even in south GA, the flies are just now starting to show up.  You may be able to find some damaged stems, but most of the widespread browning of the grass is probably due to the extreme heat and dry weather following an unusually cool and wet spring.  BSM damage kills just the last 2 leaves, and does not turn the tips of the leaves brown.  They generally do not affect leaves lower on the tiller than the top 2.  Even in our well-watered research plots in Tifton, we are only seeing 10-20% damage in the most susceptible varieties.  The current drought situation has many producers delaying their hay harvest.  This means we have more mature bermudagrass than usual (and so there appears to be more damage).  There is likely no need to spray yet, but growers should be alert and be ready to spray after the next cutting if there is a noticeable amount of damage.