Monthly Archives: June 2016

June 24, 2016 · 3:29 PM

Corn-Leaf Aphids

Corn-LeafAphid (7)

Grain sorghum is now booting and we applied initial insecticide sugarcane aphids (SCA) last week. This week we are seeing another aphid – corn-leaf aphid (CLA) in sorghum. Unlike the SCA, this aphid was seeing on the top of the leaves and near the whorl of the plant.

UGA Extension Entomologist Dr. David Buntin says (CLA) normally occur in the whorl leaves but can be found lower down on the plant too. They are not a significant pest unless they build to large numbers, but they do not cause the feeding damage that SCA do. Usually rain and beneficial insects will control them. Our SCA insecticides should kill them.

How do we know exactly when to treat for corn-leaf aphids if they become a problem? Dr. Buntin says, we do not have a definite threshold for corn leaf aphid, so just treat when aphids are numerous and leaves begin to look damaged (or chlorotic, yellowing).  If only in 2 spots I would wait and see if they get worse.

Corn-Leaf Aphids

Corn-Leaf Aphids

Sugarcane Aphids

Sugarcane Aphids

 

 

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Filed under Entomology, Grain Sorghum

June 23, 2016 · 2:25 PM

Cotton Aphids

Parasitized Aphids - Photo by Jodie Stringer

Parasitized Aphids – Photo by Jodie Stringer

We are seeing aphids in cotton now. Based on my last few years in Thomas County, this is earlier than normal. Jodie sent me this picture of aphids that were parasitized by wasps. The aphids turn a reddish color, then more white color. Sometimes you can see a hole on the backside where the larvae exit.

Here is some 5 – 6 leaf cotton that had ants crawling up the stalk. When we looked under the leaves, aphids are present. The reason these ants are crawling around the aphids, is that they are ‘farming’ the aphids. The aphids produce honeydew as they feed on the plant. The ants are after this sweet taste.

Ants 'farming' aphids

Ants ‘farming’ aphids

UGA Extension Entomologist Dr. Phillip Roberts says right now, we do need to be looking for aphids in fields. But one of the most important things we can do is watch for the naturally occurring epizootic fungus that cause aphid populations to crash. We generally see the aphids crash sometime between the last 2 weeks of June and first 2 weeks of July.

Before the crash, we may see some very small hits of aphids in ‘hot spots’. In these places, we may see honeydew (sticky, shiny material), yellowing in the terminal.  We look for gray, fuzzy aphid cadavers. As aphids build, the fungus multiplies, and aphids crash. The crash happens fast and kills all aphids within a week or so. Here is a picture of the fungus on an aphid.

Aphid Fungus

Aphid Fungus

Aphids in terminal - 2015

Aphids in terminal – 2015

Dr. Roberts has completed lots of research on cotton aphids and has not seen a consistent yield response from controlling them. Controlling aphids remains a judgment call. A few points to consider if making this decision on spraying for aphids is:

  1. If terminal has turned yellow.
  2. If the whole field has aphids (instead of just hot spot.)

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Filed under Cotton, Entomology

June 21, 2016 · 5:22 PM

Bermudagrass Stem Maggot

BremudagrassStemMaggot

We are seeing damage from bermudagrass stem maggot (BSM) at this time and will have to start treating fields. I looked at this hay field in Boston last week. Colquitt County Agent Jeremy Kichler is reporting BSM in Alicia plots at the Expo.

The hay field will have a frosted appearance after the larvae (maggot) of the fly feed inside the shoot affecting only the top shoots (usually top 2). The lower shoots are not affected. The shoots stop elongating after feeding occurs. In the U.S., only bermudagrass is a host of BSM. Below are points I try to summarize from Biology & Management of Bermudagrass Stem Maggot. Click that link to read more detail.

Bermudagrass Stem Maggot - Adult

Bermudagrass Stem Maggot – Adult

Identification

The fly is small and yellow colored with dark eyes. The fly lays its eggs on the bermudagrass stem near a node. The maggot is yellowish in color and grows to be about 1/8 inch long. It may be hard to find the maggots, because they have usually left the stem by the time the plant shows symptoms of damage. There are multiple generations each summer. The fly has a life cycle that usually lasts about 3 weeks, but can be as short as 12 days.

Management

One cultural option we have is to go ahead and cut the hay. UGA Extension Specialists Dr. Will Hudson and Dr. Dennis Hancock say if damage is found within 1 week of the normal harvest stage, go ahead and harvest the crop as soon as weather conditions allow. Once the damage becomes apparent, the crop is unlikely to add a significant amount of yield. If damage is observed within 1 to 3 weeks after the previous harvest, it is also likely that the crop will not add a significant amount of yield. The damaged crop should be cut and (if the yields are substantial enough to warrant) baled and removed from the field as soon as weather conditions allow. Leaving the damaged crop in the field will only compete with any attempts by the plant to regrow and decrease the opportunity that the next cutting will have to accumulate mass.

Control

The most important insecticide spray is the first one which should occur 7 – 10 days after cutting. We then follow up with another application 7 days following this. Below is from Dr. Hancock:

We still do not have an insecticide that can successfully eradicate the invasive bermudagrass stem maggot (BSM). However, we have been able to suppress the fly population and the associated damage by the maggot when affected bermudagrass fields received two applications: 1) applying a pyrethroid (any labeled pyrethroid seems to work) as soon as the harvested bermudagrass begins to regrow (7 – 10 days after cutting) and 2) a second application 5-7 days later. Because of the expense of these treatments, these applications should only be made if a history of BSM damage would suggest that greater than 25% yield loss from the BSM is to be expected.

BermudagrassStemMaggot (2)

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Filed under Entomology, Forages

June 17, 2016 · 8:43 PM

Plant Bugs

 

Tarnished Plant Bugs

We will now begin scouting for tarnished plant bugs. TPB have piecing/sucking mouthparts (like stinkbugs). Adults have a yellowish triangle behind the thorax with 5 distinct black dots. We want to retain 80% of our squares. Sometimes, less retention can occur even when plant bugs are not present. We need to monitor both square retention and plant bugs. Plant bugs are mobile and can move in and out of fields fast. They can be present and not causing square loss. Here is a threshold from UGA Extension Entomologist Dr. Phillip Roberts:

TarnishedPlantBugThreshold

Adult Plant Bug - Photo by Jenna Brock

Adult Plant Bug – Photo by Jenna Brock

Plant Bug Nymph

Plant Bug Nymph

At cotton scout school this week, Dr. Roberts showed us plant bugs and other insects he is seeing at this time. Colquitt Ag Agent Jenna Brock is seeing some and also some reported by Jodie Stringer down here. I ran a sweep net through one field, and did not see any plants bugs. In a field where I looked, I did find a bigeyed bug. These are not problem insects. They actually feed on small caterpillars and eggs. Minute pirate bugs look somewhat similar and are beneficial also.

Bigeyed Bug

Bigeyed Bug

 

 

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Filed under Cotton, Entomology, Irrigation

June 17, 2016 · 8:11 PM

Pond Scum

PondScum-J.Surles

Some pond scums are showing up after heavy rain from the tropical storm.. There was some in the pond behind our house as well. These blooms usually appear during the summer and fall. We do have to beware of blue-green algal blooms (cyanobacteria). These produce toxins that can be lethal to most fish and livestock. Other aquatic weeds called pond scum are duckweeds and watermeal, Euglena, diatom blooms, filamentous algae, bacterial, protozoan, and zooplankton scums.  This photo is likely blue green algae scum which was sent to me last week.

UGA Extension Aquatic Scientist Dr. Gary Burtle says, “The hot temperatures make most algaecide applications dangerous to the fish due to possible oxygen depletion. However, low dose applications of copper may thin this bloom. Try one quart to one half gallon of cutrine plus per surface acre. Then repeat each week to thin the bloom. That would be about 0.2 lb to 0.4 pounds of copper per surface acre.  Dilute 1:10 in water for application to the scum.

An alternative is to use sodium percarbonate (many different label names) at 25 lbs per surface acre and repeat weekly. Spread evenly over the pond surface with a granular spreader and boat.”

Pond Scum

Pond Scum – Photo by John Surles

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June 17, 2016 · 12:55 PM

Peanuts: Fungicide Programs Begin

Peanuts-30DAP

The Tropical Storm Colin came from the Gulf of Mexico and traveled the most important peanut production areas of the state. We had between 3 and 7 inches reported around the county. The subsequent rain will have impact on diseases affecting peanuts (and other crops). This also coincides with the time when growers are beginning their fungicide program. Also, it is the time when the peanut plant is shifting from vegetative growth to reproductive growth (flowering).

UGA Extension Plant Pathologist Dr. Bob Kemerait has this information:

Within a month after planting, the peanut crop enters the window where a traditional disease management program begins. An important principle of disease management on any crop is to apply fungicides prior to disease onset.

Aspergillus Crown Rot

Aspergillus Crown Rot

The most important disease observed in 2016 has been Aspergillus crown rot, a fungal disease that is our most common seedling disease. It is often diagnosed by the abundant black/sooty sporulation on the crown of the plant, typically just below the soil surface. The disease is most common in very hot and dry soils where the tender taproot and shoot is scorched by the surrounding soil, thus creating injury that is exploited by the fungus. The disease is also found where lesser corn stalk borers are a problem. Fungicide seed treatments are effective in managing this disease but can suffer when conditions favor crown rot. In-furrow applications can also reduce outbreaks of Aspergillus crown rot. Foliar fungicide applications after disease is observed have not been especially helpful.

Tomato spotted wilt is showing up more and more on young peanuts. It was my observation that feeding injury from thrips was severe on both cotton and peanuts this year; I am concerned that we may see more TSWV this year than we have in the recent past. While there is nothing to be done at this point, being able to diagnose the problem and to explain why the disease has occurred in a field is helpful.

TSWV 017

Tomato Spotted Wilt Virus

White mold: I have not seen white mold on peanuts thus far in 2016, but strong early-season growth of the peanut plants coupled with very warm soil temperatures can set the stage (as in 2015) for a “white mold year”. The 2016 year may also be problematic for white mold because A) many growers are on shorter rotations and B) because of the price of peanuts, growers may be reluctant to spend more money on “premium” products.

WhiteMold 003

White Mold

Growers can begin a white mold fungicide program earlier than the traditional “60 days after planting” in a number of different ways. Two popular ways include banding a white mold fungicide like Proline early in the season and also by mixing a fungicide like tebuconazole with early leaf spot fungicide applications.

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June 14, 2016 · 9:46 PM

Early Season Irrigation In Peanuts

We have been getting sporadic rainfall and periods of hot and dry weather. The early rainfall was good, but then the periods of hot dry weather have really hurt some of the dryland crops and caused some pivots to be operated near continually. Here is some information from UGA Extension Irrigation Specialist Dr. Wes Porter:

Ideally, peanut planting has finished up, and crops should be emerged and growing well. If you were able to take advantage of the early warm weather and get peanuts planted in the April throuh early May time frame, you are moving into peak water requirements in about a month. You are currently (throughout the month of June) around requiring 1 to 1.75 inches per week. If you missed the first window and have just finished up planting your peanuts in the month of May, then you are still at a low water use stage. You are ranging somewhere between 0.2 and 0.8 inches required per week.

Overwatering can hurt just as much as under-watering. Focus on keeping a record of local rainfall events and especially your irrigation applications. Just blindly irrigating a set number of times per week throughout the season will not aid you in properly meeting your requirements for the crop. Irrigating blindly will also not help in maximizing yield potential nor profit potential. Remember this requirement is IRRIGATION and RAINFALL. Irrigation may not even be required in the first few weeks.

Good record keeping and a sound irrigation scheduling strategy can aid significantly in increasing profitability in multiple ways, including reductions in irrigation applications, correlating to reductions in energy requirements, and potentially increases in yield.

WaterUsebyPeanut-2016

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Filed under Irrigation, Peanuts

June 10, 2016 · 4:07 PM

2016 Sugarcane Aphids

SugarcaneAphids 001

On Wednesday, Stephanie Holliefield in Brooks County confirmed sugarcane aphids in grain sorghum. I got calls from two growers in Thomas County today reporting SCA also. In both fields reported, no honeydew is present. Last season, we observed that once honeydew was present on the top of leaves, populations spread fast. Here is a picture of an adult and immatures under a leaf in a field today.

Sugarcane Aphids

Sugarcane Aphids

Threshold

At pre-boot, we really don’t treat until 50-100 aphids are found in 20% of the field. Last season, we found ourselves pulling the trigger later than we should have. Each situation will be different. It can be difficult to asses. We need to remember that if aphids are present in one corner of the field, they may be present in another corner, and in another spot.

Treatment

Here is updated information on our Section 18 in GA from UGA Entomologist Dr. David Buntin:

We have 2 products available, Sivanto Prime and Transform.  Things we should know about application and use of these products include;

  1.  Sivanto Prime – can be applied at 4-7 oz/acre.  The 4 oz rate will do a good job and last for at least 21 days.  Sivanto Prime last a little longer than Transform.  This product is full labeled on sorghum with a supplemental label for the 4-7 oz rates.
  2. Transform WG – has been approved again by a Section 18 for Georgia, at the 0.75 to 1.5 oz rate/acre.  However, one big change from last year is Transform CANNOT be used during flowering.  Also, we need to remember that there are only 2 applications per season.  Dr. David Buntin, UGA Entomologist recommends at least the 1 oz rate and the 1.5 oz rate is even more effective and will provide approximately 14 days of control.

Both of these products can be used on grain, silage,  forage type sorghums, and sorghum/sudangrasses.  But please remember that these products can not be used on sweet sorghum.

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Filed under Entomology, Grain Sorghum

June 8, 2016 · 8:31 PM

Morningglory Identification

I posted this last year from UGA Weed Scientist Dr. Erick Prostko. There are many species of morninglory weeds to learn in the field. We have to make sure we have proper ID for control.

Why is this important? Not all morningglories are controlled equally by certain herbicides. Here are a few examples:

  • Gramoxone (paraquat) is generally good on most morningglory species but not smallflower. 
  • Basagran (bentazon) is generally not effective on most morningglory species but will control smallflower.
  • Staple (pyrithiobac) is generally considered to be an excellent morningglory herbicide but not on tall.
  • 2,4-DB is less effective on pitted morninglory than other species.
  • Aim (carfentrazone) is considered a good morningglory herbicide but not on smallflower.

Here are some photos of morninglory UGA Extension Weed Scientist Dr. Eric Prostko shared from LSU and Virginia Tech.

Cypressvine-MG Tall-MG Red-MG SmallFlower-MG PurpleMoonflower-MG Pitted-MG Palmleaf-MG Ivyleaf-MG Entireleaf-MG

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June 8, 2016 · 7:26 PM

Cotton Ginning Assistance

USDA Provides Targeted Assistance to Cotton Producers to Share in the Cost of Ginning 

One-time Payments to Begin in July to Assist with 2016 Ginning Season 

WASHINGTON, June 6, 2016 – Agriculture Secretary Tom Vilsack today announced that the U.S. Department of Agriculture (USDA) Farm Service Agency (FSA) will provide an estimated $300 million in cost-share assistance payments to cotton producers through the new Cotton Ginning Cost-Share program, in order to expand and maintain the domestic marketing of cotton.

“Today’s announcement shows USDA continues to stand with America’s cotton producers and our rural communities,” said Vilsack. “The Cotton Ginning Cost Share program will offer meaningful, timely and targeted assistance to cotton growers to help with their anticipated ginning costs and to facilitate marketing. The program will provide, on average, approximately 60 percent more assistance per farm and per producer than the 2014 program that provided cotton transition assistance.”

Through the Cotton Ginning Cost Shareprogram, eligible producers can receive a one-time cost share payment, which is based on a producer’s 2015 cotton acres reported to FSA, multiplied by 40 percent of the average ginning cost for each production region. With the pressing need to provide assistance ahead of the 2016 ginning season this fall, USDA will ensure the application process is straight-forward and efficient. The program estimates the costs based on planting of cotton in 2015, and therefore the local FSA offices already have this information for the vast majority of eligible producers and the applications will be pre-populated with existing data. Sign-up for the program will begin June 20 and run through Aug. 5, 2016 at the producer’s local FSA office. Payments will be processed as applications are received, and are expected to begin in July.

Since 2011, cotton fiber markets have experienced dramatic changes. As a result of low cotton prices and global oversupply, cotton producers are facing economic uncertainty that has led to many producers having lost equity and having been forced to liquidate equipment and land to satisfy loans. The ginning of cotton is necessary prior to marketing the lint for fiber, or the seed for oil or feed. While the Cotton Ginning Cost-Share program makes payments to cotton producers for cotton ginning costs, the benefits of the program will be felt by the broader marketing chain associated with cotton and cottonseed, including cotton gins, cooperatives, marketers and cottonseed crushers and the rural communities that depend on them.

The program has the same eligibility requirements as were used for the 2014 Cotton Transition Assistance Program, including a $40,000 per producer payment limit, requirement to be actively engaged in farming, meet conservation compliance and a $900,000 adjusted gross income limit.

To learn more about the Cotton Ginning Cost-Share program, visitwww.fsa.usda.gov/programs-and-services/CGCS/index or contact a local FSA county office.

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