Weed of the Week: Hairy Bittercress

Authors: Ashley Averitt, Wes Dyer, Coleman Torgersen

Description

Hairy bittercress, Cardamine hirsute L., depending on its location, is a winter or summer annual weed. It is most often found in landscape areas, container-grown plants, and greenhouses. Its stems branch at the base and can achieve a height of 12 inches. Growing on the central leaf stem is 2 to 4 pairs of leaflets that are alternately arranged. Each leaf occurs on a petiole that is distinctly hairy. One should take note that the upper leaves will be noticeably more hairy than the lower leaves. This weed flowers in clusters while each individual flower is small (2-3mm) and composed of 4 white petals. The fruit (seed capsule) is a silique, which is a long, narrow capsule with many seeds. Siliques can explosively spread the seed as far as 10 feet from the parent plant. It tends to grow in disturbed soils and will form dense mats of rosettes over an area.

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Identifying Characteristics

Hairy bittercress has long, narrow siliques and round leaflets that are alternately arranged. Also, this weed has white flowers with 4 petals in dense clusters at the end of the stem.

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Management

Improving drainage can be a great way to deter this moisture-loving weed. If you have severe infestations of hairy bittercress, it may require chemical treatment. Post emergence herbicides such as 2-4 D, triclopyr, clopyralid, dicamba, or MCPP should be used.

Finally, don’t forget that wild hairy bittercress is edible! It is best to gather in early spring or late fall when the leaves are tender. It adds a peppery bite to raw salads, and can be cooked and added to soups.

Lawn Care Operators – Application Data Management

As Lawn Care Operators (LCO’s) you’re managing numerous properties – each somewhat different. And as part of your state’s pesticide applicator regulations, you’re responsible for keeping up with a minimum amount of information concerning every application. IMG_0721 (2)

So take a few notes about what you should be noting! You can do this via smart phone app, or just create a paper trail for every account – as long as you can show it to the inspector and regulators. Read here for Mississippi’s Bureau of Plant Industries regulation of professional services.

Here’s the main ones I think are pertinent:

Street Address
Latitude and Longitude
Date of application
Time of application
Applicator Name
Contract Number
Application Type (ex: preemergence, broadleaf and/or grass postemergence, fertilizer, fungicide, insecticide … )
Granular or Liquid Application
Spot Spray?
Complete Coverage?
Application material active ingredient
Trade Name
Reason for Application
Rate of each material applied
Area covered with treatment
Use restrictions for material and how directions were followed
Whether product was irrigated in
Next rain event
Soil Temperature
Air Temperature
% Cloud Cover
Whether Soil moisture was dry, adequate, high, excessive
Humidity
Turf stage of growth
%Turf green cover
When was the property last mown? Is mown a word or is it mowed?
And then just notes about the property:
What weeds, disease, insects were present
In what stage
Recommend follow up, Yes or No?
Always take some pictures of problem areas.
Some others that might prove helpful for your logs would be:
whether the homeowner was present
were they informed of application
if so, how: phone, email, person? when?
Can you think of other info that might be useful?

 

Yes, there’s an app for that. In fact, there are several. One of which is DoForms (there are several others). Most are an online database accessible via smart phone. You basically make a new form that asks you to fill in responses to different types of questions. Ideally, your applicator would fill in questions at each site.

Grow Grass,

Jay

Weed of the Week: Chamberbitter

 Authors: Jed McCoy, Corey Garrison, Justin Hickman

What is Chamberbitter?

Chamberbitter (Phyllanthus urinaria) is a member of the Spurge family (Euphorbiaceae), sometimes referred to as gripeweed, leafflower, or little mimosa.  It is native to Asia, but has found its way across the southeast and into Texas. Chamberbitter is a warm-season broadleaf annual and usually emerges around May or June when the soil temperatures have warmed to approximately 70oF.  It spreads by seeds that are located on the bottom side of the branch.  Ornamental beds and turfgrass are the two most common places to find Chamberbitter.  In South America, this plant is believed to be good for medicinal purposes; specifically, treatment of kidney stones.

Chamberbitter Overview Blog

What does Chamberbitter look like?

Chamberbitter can grow tall and thin, which can be aesthetically unpleasing.  The leaves grow in two alternating rows.  Leaves are thin and smooth which resemble the seedling of a mimosa plant.  It is best identified by the fruiting structures on the underside of the branch which produce numerous seeds.  These seed capsules can explode and spread seeds over a large area.  Also, like some spurge, if you break the stem, it will produce a milky white sap.

Chamberbitter seeds Blog

How do I control Chamberbitter?

Chamberbitter can be a difficult weed to control.  It is drought tolerant and grows rapidly.  Seeds on the underside of the plant can be produced in as little as two weeks.  If making a pre-emergent herbicide application, Chamberbitter control is often unreliable because it germinates later in the spring than most summer annual weeds.

Cultural Practices:

  • Frequent mowing
  • Hand pulling
  • In landscape beds, 1-3 inch mulch layer will block seed from receiving light

Chemical Control

  • Atrazine
  • Three-way herbicides containing dicamba, 2,4-D, mecoprop (MCPP)
  • Isoxaben (Gallery 75DF)

 

Concerned about Bermudagrass Winterkill?

Turf managers across the Southeast are all aware that temperatures in 2014 have been lower than winters in the recent past. This has brought about renewed concern for winterkill of bermudagrass.  Will the turf survive the winter? Will spring green-up be delayed? Will replanting be necessary?  Research conducted at Mississippi State University has shown that newly planted bermudagrass is more susceptible to winter injury than mature stands. Seeded varieties, when planted in May or June, had a better chance of surviving the first winter than when seeded in July through September.  If you don’t wish to wait for spring to find out, perhaps there is a faster way to estimate the damage.  Bring turf samples indoors today.

At MSU a new bermudagrass variety trial was planted on June 28, 2013. This experiment contains 35 varieties (17 were planted vegetatively and 18 were seeded).  The plots were visually well established before fall dormancy. Then, just like probably many of you in the middle of this long winter, we started anticipating.  Our low temperature here was 8 degrees. Will we have to replant?  We decided to sample.  On February 19 we pulled one two-inch plug from each plot of one block of the field experiment. We set these plug samples into pots filled with sand and placed them in a 75 degree greenhouse (photo 1).  On February 26, after one week, 31 of the 35 plugs samples were displaying at least one green shoot (photo 2). After two weeks, on March 5, 33 plugs had shown new growth (photo 3).  The two samples that have not yet shown signs of life are from seeded varieties.

Of course this sampling exercise was not a scientifically valid test for winter survival. The real test will come later on this spring when each entire plot is rated for percent survival.  This is a good indication however that the experiment will not need to be completely replanted. We can rest a little easier. Good luck to all you real turf managers out there who are losing sleep over the threat of winter injury.

Photo 1. February 19, 2014

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Photo 2. February 26, 2014

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Photo 3. March 5, 2014

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Spring Has Sprung

Being a turfgrass extension specialist, I get calls and questions ranging from basic to bizarre – I got one the other day pertaining to growing grass on fish pond banks irrigated with salt water. But the one I get most often is this: “what should I spray on my lawn to prevent weeds.” There’s no simple answer, and the conversation always twists and turns depending upon the person’s agronomic background and whether they have a pesticide applicator’s license.henbit

Before I make a recommendation, I try to gather as much information as possible. What type grass do you have? What’s your location? Do you have an applicators license? What it comes down to is usually this: time and money. But that’s not a quick and easy answer like most folks expect.

Grow Grass First – I suspect that 90% of the homeowner issues I encounter aren’t going to be solved by applying something from a jug. Proper fertility is important, and so is proper grass selection. But if you’re trying to grow bermudagrass under a live oak, herbicides aren’t going to help. I recommend this publication for a starter guide to homeowners. For coaches and athletic field managers, I recommend managing sports fields in MS. Inevitably, I get asked to come and visit. If it’s an emergency, and you’re dying to know what disease you’ve got, you’d be best off sending some high quality images and a sample to Clarissa over in the diagnostics lab.

Timing – The issues surrounding spring preemergence are too numerous to mention. Careers have been built upon understanding the most minute detail of single herbicide chemistries. Ultimately, timing is the major obstacle. It’s important to understand that not all pre’s work the same way, and they generally have very limited postemergence activity. That’s to say, if crabgrass has already germinated, guess what, you’re not going to preemergently control it. For most of MS, it’s not too late to apply a pre. Crabgrass has barely started to break in Starkville, and even if it already has down on the coast, you’ll have germination for the rest of the spring. If you are getting out there late, choose a pre/post combination, such as Barricade (prodiamine) tank mixed with Drive (quinclorac), or choose a herbicide that has both pre and postemergence control, such as Dimension (dithiopyr) or Specticle (indazaflam).

Mode-of-Action – If you’re battling resistance, or just trying to prevent it, you ought to be rotating modes-of-action (MOA’s). All of us need to be proper stewards of the chemistries we’ve got. Be aware that herbicides have different MOA’s. That is, they kill weeds differently. Some inhibit photosynthesis (atrazine and simazine); others inhibit cellulose biosynthesis (Specticle); still, others inhibit mitosis (DNA herbicides like prodiamine and pendulum). Here’s a list of common MOA’s. Notice that some are solely preemergently active (Pre). Others are pre/post active. And others are only post. Always read the label when applying any type of pesticide.

Common Turf Herbicide MOA's

Keep an eye out for future publications with more detail. And keep in mind that root pruning is a serious issue with almost all of the pre herbicides. Ronstar may be the safest to new roots of bermudagrass, but it’s expensive. If you suspect winter kill, you might want to avoid applying a pre to bermudagrass if you can keep from it. That said, you’ll have very few herbicides available for post control of problematic weeds like goose and crabgrass.

Finally,

FormulationIf I were a homeowner and a DIY’er, I’d choose a granular weed and feed type application. It’s effective, as long as one gets good coverage, and it doesn’t require special spray equipment. DNA herbicides, such as prodiamine and pendimethalin, often come impregnated on both corn cob and/or fertilizer. I don’t typically recommend fertilizer prior to full green up, so buyer beware: fertilizer application isn’t needed until almost 100% green up. Look for the pre herbicide coated on an inert carrier like corn cob or fertilizer free granular.

There are numerous other variables, but these are the low hanging fruit.

Enjoy the warmer weather,

Jay

 

Yellow Woodsorrel

Christo Sullivan, Doug Martin, Jordan Billingsley 

AboutYellow Woodsorrel (Oxalis stricta) is a medium-sized edible plant that thrives in lawns and woodlands across the United States and Canada. It can also be found in Europe, Africa, Asia, Japan and New Zealand. The flowers can be used to make yellow, orange, red and brown dyes. Another common name is “Oxalis”, which means “sour” due to its oxalic acid content. Oxalic acid can be toxic when consumed in large quantities because it inhibits the absorption of calcium. Yellow Woodsorrel is a cool season perennial in the Woodsorrel family (Oxalidacea), but may act as a summer annual in certain environments.  It reproduces by seed and occasionally stems.

Rose Garden by Oak tree (Small)

Identification – Yellow woodsorrel introduces itself from a taproot and forms small, erect, bushy plants up to 20 inches tall. The stems are slender, gray-green, pubescent, slightly ascending, and branched at the base. They will occasionally root at the nodes. The leaves of yellow woodsorrel are alternate with three heart-shaped leaflets. They are pale green, up to 4/5 inch across with long petioles. The flowers are yellow with five petals and are up to ½ inch across. It is often mat forming and more common in cools-season turf species, such as tall fescue. It can be very common in greenhouses and container nurseries because its seedpods can distribute seeds up to several feet.

MSU GC (Small)

Control

Cultural– Hand-weeding is effective before seeds are formed.  As always, the best weed control is a dense turf sward. Proper mowing, fertilizing and irrigation ensure vigorously growing turf.

Chemical –

Many pre and post-emergent herbicides are effective.

Pre-emergent herbicides include:

Pendulum
Atrazine
Ronstar
Barricade
Balan
Dimension

Post-emergent herbicides include:

Basagran
Confront
Dicamba
Atrazine
Turflon
2,4-D
Monument

And many 3-way mixtures sold at in lawn and garden sections  (often labelled as Trimec Southern or for Broadleaf weed control).