Seminole Crop E News

Agricultural News for Farmers and Agribusiness in SW Georgia

Archive for December, 2013

Aphid Numbers Rising

Posted by romeethredge on December 24, 2013

I’m finding a good many aphids in some grain fields, others have moderate to low numbers. I’ve mainly been looking at wheat and oats. In the photos below that I took you can see 2 types of aphids. Also you can see that they are reproducing.  The green aphids are usually greenbugs and they cause discolored lesions on the leaves.
Dark reddish-brown aphids are most likely bird-cherry oat aphids.  These aphids do
not cause feeding lesions but they do transmit barley yellow dwarf.  Aphids suck juices from the leaves and cause some growth problems.

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Aphids vector a viral disease named barley yellow dwarf (BYD) and a related disease called cereal yellow dwarf. Wheat and barley can be severely damaged, but oats are most susceptible to this disease. BYD is present in most fields in most years throughout Georgia. Yield losses of 5-15% are common but losses can exceed 30% during severe epidemics. Infection can occur from seedling emergence through heading, but yield loss is greatest when plants are infected as seedlings in the fall. Although all aphids can potentially transmit certain strains of the virus, infections in the Southeast are mostly associated with infestations of bird cherry-oat aphid and rice root aphid. Planting date is the single most important management practice, with early plantings generally have greater aphid numbers and greater BYD incidence than late plantings.

A single, well-timed insecticide application of the insecticide lambda cyhalothrin (Karate Zeon, Silencer, and similar products) or gamma cyhalothrin (Declare) also can control aphids, reduce the incidence of BYD and increase yields.  In southern Georgia, the best treatment time usually is at full-tiller stage in early to mid-February. But, scout fields for aphids at 25 – 35 days after planting and during warm periods in January to determine if an insecticide application is needed. A lambda cyhalothrin or gamma cyhalothrin treatment at full tiller can be applied with top-dress nitrogen. OP insecticides, such as dimethoate and methyl parathion, also will control aphids but are not effective in preventing barley yellow dwarf infection.

To sample aphids, inspect plants in 12 inches of row in fall and 6 inches of row in winter. In spring, inspect 10 grain heads (+ flag leaf) per sample. Count all aphids on both the flag leaf and head for making control decisions. Sample plants at 8 to 16 locations per field. Treat when populations reach or exceed the following thresholds:

Seedlings: 1 bird cherry-oat aphid per row foot, or 10 greenbugs per row foot.

2 or more tillers per plant: 6 aphids per row foot.

Stem elongation to just before flag leaf emergence: 2 aphids per stem.

Flag leaf emergence: 5 aphids per flag leaf.

Heading emergence to early dough stage: 10 aphids per head.

Do not treat for aphids after mid-dough stage.

 

Thanks to Dr. David Buntin, UGA Entomologist, for the aphid information.

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Posted in Agriculture, Entomology | Tagged: | Leave a Comment »

2014 Costs and Net Returns

Posted by romeethredge on December 24, 2013

Here is an estimate of 2014 costs and net returns for the major row crops grown in Georgia, prepared by UGA Extension Ag Economists listed on the sheet.

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Posted in Economics | Tagged: | Leave a Comment »

Weeds in Wheat

Posted by romeethredge on December 23, 2013

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This wheat has 2 or more tillers per plant, so It’s ok to use MCPA mixed with Harmony Extra on it. It needs it, as there is a high population of wild radish in this field.

 

Here’s some good wheat weed management info from UGA.

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Posted in Weeds, Wheat | Tagged: , | Leave a Comment »

Question of the Week – Stinging Nettle

Posted by romeethredge on December 23, 2013

 Last week I had a photo of Stinging Nettle I found in a pasture. Marvin Stewart, Dow Agrosciences Representative from Tallahassee had the first correct answer. It has tiny short hollow needles with poison in them that will affect you if you brush up against it. So do not touch it. It will cause a burning rash. Here’s a closeup where you can see the needle-like structures.

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This week I have something different to ask you about. We were traveling near Live Oak Florida last week and I saw dozens of these mounds, about 6 inches across, at a rest stop. I thought at first they were fire ant mounds but there was no…… nevermind, I may give away the answer. What caused these mounds?

photo (7)

Posted in Weeds | Tagged: | 1 Comment »

Oat problems

Posted by romeethredge on December 20, 2013

We are having some oat problems. Oats are grown mainly for cattle to graze but we also grow it for grain, mainly to use for seed the next year, and for a covercrop. Cattle love to graze oats and they have nice wide leaf blades. Our newer varieties have had genetic resistance to rust but last year that broke down and we saw it come into our oats.

We are seeing that again. Today, I found some rust here in Seminole County. What to do about it is the question. If you are grazing it you can’t put on fungicides or you could but you would have to wait for the required time before you put the cattle back into the oat patch. If you are growing oats for seed then a fungicide may be warranted if rust is nearby.

Before you spray , check for aphids as they are abundant now and can carry Barley Yellow Dwarf Disease.

Here’s a close up of the rust on the leaf that  I found today.

oat rust1

Here’s a further off shot.

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Dr. Alfredo Martinez, UGA Plant Pathologist provided me this information concerning fungicides.

Wheat and oats fungicide chart common questions

FUNGICIDE WHEAT grain OATS GRAIN OATS FORAGE OBSERVATIONS
Propiconazole(tilt) YES YESTilt can be applied up to 45 days prior to harvest Yes.Do not apply within 30 days of harvest for forage or hayPage 8 of label  
Metconazole(Caramba) YES YES30 days minimum time from application to harvest. No   livestock feeding restrictions) NOT sure, no clear label for forage. It says “no livestock   feeding restrictions”  
Pyraclostrobin(Headline) YES YESApply no later than the beginning of flowering (Feekes   10.5; Zadok’s 59) YESDo not harvest grain or feed green-chopped oats within 14   days of last applicationPage 20 of label Up to feekes 10.5 no more than this growth stage
Azoxystrobin(Quadris) YES NO NO  
Prothioconazole(Proline) YES YESDo not apply within 30 days of harvest NO  
Propiconazole + triflouxastrobin(Stratego) YES YESDo not apply after Feekes growth stage 8 (the ligule of   the flag leaf emerges). Do not apply within 40 days of harvest YESOnly one app. Do not graze treated area for 30 days; do   not harvest in 30 days for forage or 45 days for hay page 8 on label  
Prothioconazole + triflouxastrobin(Stratego YLD) YES NO NO  
Propiconazole + azoxystrobin(Quilt) YES Yes Yes  Do not apply within 7 days of harvest for forage or hay
Quilt XL YES Yes Yes  Do not apply within 7 days of harvest for forage or hay
prothioconazole  +   tebuconazole(Prosaro) YES NO NO  
Pyraclostrobin + metconazole(Twinline) YES YESApply no later than the beginning of flowering (Feekes   10.5; Zadok’s 59) Not sure. It says do not harvest BARLEY for hay  14 days of last application. No directions   for oats.  
Tebuconazole + trifloxystrobin(Absolute) YES NO NO  
Tebuconazole(Folicur) YESNot for powdery mildew

NO

NO

 

 Here’s another informational chart provided by Dr. Dennis Hancock, UGA Forage Scientist.

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Posted in Agriculture, Entomology, Forages, Plant Pathology | Tagged: , | 2 Comments »

Leyland Cypress Problems

Posted by romeethredge on December 20, 2013

Leyland Cypress Dilemmaleyl

The Leyland cypress (x Cupressocyparis leylandii) is a beautiful evergreen tree that has become one of the most widely used plants in commercial and residential landscapes as a formal hedge, screen, buffer strip, or wind barrier.  However, because of its relatively shallow root system, and because they are often planted too close together, Leyland cypress is prone to stress. Once the plants become stressed, disease may follow.

 Best management practices minimize stress to the tree; and subsequently a healthier tree. The Leyland cypress is best suited for fertile, well-drained soils.  They will not stand wet soils and will respond to ‘wet feet’ by getting sick or dying.  Mulch is desired after planting, but do not mulch deeper than four inches.

Do not water any more than twice a week even during a drought – once a week would be best.  Water soils to a depth of twelve inches and then let them dry out. Soils need to dry out between watering to protect the roots. Three-quarter to one inch of water per week is recommended.

Do not plant Leyland cypress trees closer than eight feet apart.  This is a common problem in the landscape.  Trees may reach 50 feet in height and 20 – 30 feet in width.  When limbs touch, they cause wounds that can be infected by these diseases.

 Okay, Leyland cypress trees may get infected with both root rot and foliage diseases.  Phytophthora root rot and Annosum root rot are important root diseases.  In the landscape, Phytophthora root rot primarily affects smaller plants; larger, established trees are rarely affected by this disease.

Annosum root rot is uncommon in the landscapes.  Leyland’s at new construction sites are more susceptible to Annosum root rot – especially where pine clearing has taken place.  This is because this disease develops through fungal spores infecting freshly cut pine stumps.  The fungus then grows through the stump and its root system, infecting adjacent Leyland cypress trees through root contact.

No fungicides are recommended for root rot diseases. There is no effective control once the tree is infected.  To avoid Phytophthora root rot, establish Leyland cypress in tilled and well-drained soils. Avoid over-irrigating, especially during establishment.

Leyland cypress can also be infected with foliar diseases such as Seiridium Canker and Botryosphaeria (Bot) Canker.  However, UGA Pathologists consider these diseases as more secondary diseases resulting from other stresses.  Seiridium canker can infect any age and size tree with no cultivars known to have resistance. Fungal spores spread from infected trees by water splashing (rain) and pruning tools. In the landscape, fungicides are seldom used and they provide no control once infection has taken place.

Bot canker symptoms resemble Seiridium canker as yellowing or browning of shoots and branches.  The main trunk may develop cankers that produce ‘ooze’ from the infected area. The only method of control, as suggested for Seiridium canker, is cultural control.  Avoid environmental and cultural stresses that predispose the plants to infection.  Also, remove disease twigs and branches to prevent disease spread.

Note from the beginning of this article, stress is the culprit.  UGA Extension Pathologist, Dr. Elizabeth Little described the myriad of Leyland cypress problems all across the state.  Dr. Little provided one underlying message:  Don’t spray.  UGA does not recommend fungicides (even though some fungicides are labeled) for the diseases of Leyland cypress because of little fungicide effectiveness and the fundamental association of disease to cultural problems.

But wait!   What is one common environmental factor across Georgia this year?  Rain! Leyland cypress typically has problems with drought; however, they can also have problems with wet soil.  Dr. Little agreed that the high number of Leyland cypress issues today are likely a delayed response of the environmental impact of rain this season.

Can we control the environment? Nope.  What should you do if your Leyland cypress gets disease?  First, cut out dead limbs ONLY. Clean your shears periodically.  Second, note cultural practices which induce stress your Leyland cypress trees.  This may be too much mulch, overwatering, or not allowing sufficient canopy space.  If tree limbs touch, remove every other tree to allow for space.  Solving Leyland cypress problems usually come down to cultural practices since there is little else we can do.

Most of this post is from an article by Andrew Sawyer, Thomas County Extension. Information from this article was taken from UGA Publication, “Diseases of Leyland Cypress In The Landscape.”

Posted in Agriculture, Horticulture, Plant Pathology | 1 Comment »

Question of the Week – Millionaires and Tobacco

Posted by romeethredge on December 20, 2013

Yes, the north Florida town of Quincy had a banker at Quincy State Bank,  Mr. Pat Munroe, who encouraged folks to buy Coca Cola stock when it first went public which turned out to be a very good time, it was 1919. The value went up and they had many “Coca Cola millionaires” in this farming community that grew a lot of tobacco. “The Leaf”, from tobacco leaf,was and is a theater in downtown Quincy and was important to the community and has been renovated with benevolent donations from the millionaires, it has been told.

Now for this week’s question: What is this weed I found in a pasture and is it anything to worry about?

photo[1]

Posted in Agriculture, Weeds | Tagged: , | 2 Comments »

2014 – What to Grow?

Posted by romeethredge on December 13, 2013

What are our planting options for 2014?

Here’s a good Ag economic return outlook by our UGA Extension Ag Economists.

Thanks to Dr. Nathan Smith.

One chart is Non irrigated and the other is for irrigated production.

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Posted in Economics | Tagged: | Leave a Comment »

Corn for 2014?

Posted by romeethredge on December 13, 2013

We are trying to figure out what to plant in 2014. It looks like we will have a mixture as usual but the crop mix of acres allocated is the question. Here’s some information and some slides about corn from Dr. Nathan Smith UGA Extension Ag Economist.

“Corn is not going to bring the prices we’ve had
but I still think it will be above $4.00 next year so maybe $4.50 to $5 for
South Ga.   Acreage will slip some next year but unless drop by more
than 1 million in the US, probably will have same 14B bu
production.   In that case, need more exports and feed
use.   Ethanol use is somewhat limited in growth.  The 10% blend
wall has been reached and price has to compete with gasoline.  I think
lower prices will help grow demand in these areas but if we overproduce it will
depress prices as demand won’t be able to keep up. “

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Posted in Corn, Economics | Tagged: , | Leave a Comment »

Rattlesnake Weed

Posted by romeethredge on December 12, 2013

Florida betony, also called rattlesnake weed is a problem weed in both turfgrasses and ornamentals. We are not 100 percent certain of the origin of this plant.

Florida betony is a “winter” perennial and,  has a square stem with opposite leaves. Flowers are usually pink. It has the unique characteristic of producing tubers that look like the rattles (buttons) of a rattlesnake, hence the name “rattlesnake weed” .

                  Betony1  Flower and foliage of Florida betony.

betony2

 Tubers of Florida betony that look like the rattle of a rattlesnake, hence the name “rattlesnake weed.”

The tubers are edible and some people relish their crisp, succulent flavor — who knows, maybe one day we will be figuring out how to grow Florida betony instead of killing it! Florida betony actively grows in the mid- to late fall and spring months. During the extreme heat of the summer months, growth of Florida betony slows and the plant may become dormant.

Atrazine is recommended for use on centipedegrass, St. Augustinegrass, zoysiagrass and dormant bermudagrass. Spot treatments of glyphosate (Roundup, others) also can be used to control Florida betony. The turfgrass will be severely injured or killed, however, if glyphosate contacts green turfgrass leaves.

The preferred time to treat Florida betony with sprayable formulations of atrazine is mid- to late October during the fall growth flush. An additional atrazine application in mid- to late February should coincide with the spring growth flush on warm season turfgrasses. Do not apply fertilizer-based atrazine products such as Scotts Bonus S to centipedegrass during late fall or late winter as applications of fertilizer to centipedegrass can predispose this warm-season turfgrass to winter injury.

Few herbicides are available to control Florida betony in ornamentals. Several cultural practices, however, can provide good control of Florida betony in landscape situations. Coarse textured mulches such as pine straw or pine bark applied to a depth of 2 to 4 inches, will smother the plant and help limit the establishment of Florida betony. Landscape fabrics also may be used under various types of mulches and will help prevent Florida betony emergence. Other non-chemical control options include hand-pulling and hoeing. Since this weed reproduces from underground tubers, you must completely remove all tubers when hand-weeding.

In ornamentals, dichlobenil (sold under the trade name Casoron®) provides excellent control of Florida betony in most established woody ornamentals. Dichlobenil is labeled for use in a wide variety of woody shrubs and trees, roses and English ivy, but it is not recommended for use in either annual or perennial flowers. Dichlobenil is a volatile herbicide that readily escapes as a gas under high air and soil temperatures. The ideal time to apply dichlobenil to control Florida betony is from early November through mid-February. Cool temperatures at this time of year will help prevent dichlobenil loss from the soil and will improve Florida betony control.

Products containing the active ingredient glyphosate (i.e., Roundup®, numerous other brand names), can be used to control this plant if applied as a post-directed application (spray or applied directly to Florida betony plants without contacting desirable plants). Also consider using glyphosate if you are going to establish a new ornamental planting in an area containing Florida betony. For best control, apply at the time of Florida betony flowering. Glyphosate can cause severe injury if the spray mist contacts either the green bark or foliage of ornamentals. Avoid applying glyphosate near ornamentals on windy days.

Most of this information comes from a UGA publication that can be accessed here, http://www.caes.uga.edu/publications/pubDetail.cfm?pk_id=7648

Posted in Horticulture | Tagged: | Leave a Comment »

 
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