Thursday, May 23, 2013

Louisiana Master Naturalist Program-Greater New Orleans Chapter

Spiders and bats and gators...OH MY!
Alligator mississippiensis  at Jean Lafitte National Park

Impacts of Katrina on Bayou Sauvage lesson
The Louisiana Master Naturalist Program in the Greater New Orleans area is upon completion of a successful intensive series of naturalist workshops. 

What is a naturalist? A naturalist is an individual who studies natural history of the world, and attempts to understand the ecology, biology and ecosystem functions of living and non-living things. Through careful observation, students were trained how to look at nature in its complexity, in an attempt to understand and capture the beauty of ecosystems of Southern Louisiana. The training sessions spanned from late February and will continue to early June, and many ecosystems have been the palette for study. These included Jean Lafitte National Park, Bayou Sauvage Wildlife preserve, Northlake Nature Center & Big Branch, Turtle Cove, UNO Cerf, The Louisiana Nature Center, and Bayou Dupont. Students have learned a plethora of systems ranging from botany, mycology, zoology, hydrology, geology, and lichenology. 
Steminitis sp. at 2013 BioBlitz at
Jean Lafitte National Park
The ultimate goal is to "prime" students to look at nature and make connections with specific observations. The class is not designed to create world renowned experts, but to educate students about the natural history of Louisiana. 

There will be a class offered every Spring and Fall, and chapters in other areas of the state are in the works. More info to follow on the future classes. If you would like to get on the La. Master Naturalist-GNO list serve please email lamasternatgno@gmail.com.

Wood ear fungus, Auricularia sp. at Louisiana Nature Center





Wednesday, May 8, 2013

Blossom-end rot of tomatoes

Lately, I have received a lot of phone calls about this particular disorder, so I thought I would share some information and management strategies for this particular disorder.

Blossom-end rot is not caused by living causal agent, like a pathogen, but rather, a deficiency in calcium. This disorder is common in tomatoes, peppers, squash, and watermelons. If you had your soil tested, and the results suggested you have an adequate level of calcium in your soil, how did your tomatoes get a deficiency in calcium?

NCSU PDIC_Lookabaugh
Calcium moves quite slowly in plants and even slower in fruit, so adequate levels of calcium could still result in this deficiency. Indirectly, this disorder is caused by excessive levels of moisture or not enough moisture. Considering the excessive rainfall New Orleans received last month (about the time your tomatoes were in flower), it is not surprising to see a lot of blossom end rot. This disorder can affect all ages of plants, but is more common in 1/3-1/2 grown tomatoes. 

It begins as a small, water-soaked spot and develops into a dark brown, leathery spot that may involve half the fruit. The surface of the spot shrinks and becomes flat or sunken. Blossom-end rot is caused by a lack of calcium in the developing fruit. The uptake of calcium from the soil by the tomato plant can be reduced by fluctuations in soil moisture – either excessively wet soil or excessively dry soil.

The disorder commonly occurs when plants are growing rapidly and luxuriantly early in the season and are then subjected to prolonged dry weather. The disorder may be more serious on the windward side of a garden and on staked tomatoes rather than on unstaked or bushy plants
.

Prevent blossom-end rot by maintaining a soil pH around 6.5 and uniform soil moisture by irrigating and mulching, and avoid heavy applications of nitrogen.


Control blossom-end rot by spraying foliage with 2 level tablespoons of 96 percent calcium chloride in 1 gallon of water at seven- to 10-day intervals. Do this for three to four applications. Begin spraying with first appearance of symptoms. Overdosing plants with calcium chloride may result in leaf burn. Spray on cloudy days or wait until the sun is low.

Calcium nitrate also may be used. Use 1 rounded teaspoon per plant. Apply calcium nitrate into the soil about 8 inches from tomato plant stems. A second application may be needed several weeks later as well. If foliar applied, use 2 level tablespoons per gallon of spray applied late in the day.

Monday, May 6, 2013

Spring is here and so are plant diseases!

Azalea gall caused by Exobasidium
Many times I receive phone calls from the public concerning plants in the landscape or vegetable garden becoming sickly, showing symptoms of some kind. The first feeling I get when receiving these phone calls is a feeling of excitement, as if I am a detective assigned to a case.

First things first, gather and organize the clues. The clues are the in the form of symptoms, signs and environmental condition in which the victim, I mean plant, is found. The symptoms are defined as any abnormality in “normal” growth of the plant. Signs are evidence of a pathogenic agent on the symptomatic plant; a few examples are mycelium (white fuzzy strings) and spores for fungi, and ooze for bacteria. The signs in combination with symptoms and pattern of symptomology on individual plants and/or groups of plants can paint a beautiful story for the detective or plant diagnostician.

Plant pathologists utilize the disease triangle as their hierarchical concept to determine the disease. Within the disease triangle, there are three parameters that work in a matrix to determine level of disease; they are susceptible host, pathogen, and environment. The level of each parameter will work in synchrony to determine the output, which is disease progress and severity.

I will survey some common problems I have seen this Spring:

Fire blight of pear and relatives:



Shepherd's crook symptom on flowering pear.
Fire blight is a disease common in Southern Louisiana caused by the bacterium Erwinia amylovora. Over 130 species of plants including: pear, apple, quince, hawthorne, contoneaster and mountain ash, are susceptible to this pathogen. Symptoms are observed as Shepherd’s crook necrotic foliage, in which the leaves appeared scorched and remain on the petiole or stem. This disease has been observed on Pyrus spp. including ornamental and fruit species. This disease is favored by warm, wet weather and spread by pollinators and wind driven rain. Improper fertilization, either too much or too little also favors this disease. Managing fire blight in the landscape is mostly management of fertilizer, planting resistant cultivars, pruning infected wood and lastly, chemical control.
Fire blighted pear tree
When pruning out diseased tissues, cuts should be made 12-14” down from the symptomatic tissues in the growing season and 8-10” down from symptomatic tissue in the dormant season.  Pruning shears should be sterilized with isopropanol between cuts to prevent the spread of the bacteria between cuts. Copper fungicides, such as Kocide 2000, can be sprayed following the label recommendations for the particular plant; keeping in mind copper can be phytotoxic to some plants. You should always read the label before spraying fungicides.

Powdery Mildew on rose

Powdery mildew on rose leaf

Conidia in white mat on rose flower
Powdery mildew is a disease caused by a fungus and can affect many plants including roses, crapemyrtles, dogwoods and many cucurbits. The disease is usually favored by warm dry weather by day, and cool damp weather by night, usually falling in or around the spring and fall for southern Louisiana. The disease is observed with new growth being distorted and dwarfed often covered in a mat of white “fuzzy stuff”, and old growth and flower buds appearing twisted and distorted also covered in white fuzzy growth. The white fuzzy material are the asexual spores of the fungus called conidia. The conidia are produced in chains and are abundant. This is how the pathogen spreads so quickly under favorable environments. Proper pruning to thin out the canopy, proper fertilization, and avoiding overhead irrigation can help prevent this disease. This disease can be managed with the following sprays:  3% baking soda and horticulture oil solution, noting the temperature limitations on oils, chlorothalonil, and copper sulfates. You should always read the label before spraying fungicides.
Conidia on rose leaf magnified at 4.5x with dissecting microsope










Daylilly Rust

streaking yellow symptom on laylilly
Daylilly rust is a disease caused by the fungus Puccinia hemerocallidis. The most obvious symptoms of this disease are yellow streaks  turning brown with age on the upperside of the leaf coupled with orange pustules of spores found on the underside of the leaf observed as yellow to orange raised areas at individual lesions. The disease was first identified in the United States in 2000, and quickly spread to 30 states by 2001. The disease is spread by wind carried spores that are developed on lesions. The rusts are a particularly interesting group of diseases in that many of the species of fungi that cause rusts require two completely distinctive hosts to complete their life cycle. In the case of daylily rust, daylilies are the primary host, where species of Patrinia  are the secondary host where sexual reproduction occurs and new genetics are generated. The best preventative method of management is by using resistant cultivars, and avoiding highly susceptible cultivars. Lists of resistant and susceptible cultivars can be found at this website: http://plantclinic.cornell.edu/factsheets/daylilyrust.pdf.  Another management strategy to limit the severity of this disease is to remove infected, dead tissues in the winter and burning or sending them to a landfill. In addition, daylily growers should avoid close proximity plantings of Patrinia spp. and Daylillies so the rust cannot complete its life cycle. Preventative fungicide sprays can help reduce the devastation of this rust disease. A few sprays available to the home owner are under the chemical names neem oil, potassium bicarbonate, sulfur, or Bacillus subtilis (Serenade, Plant Guardian). You should always read the label before spraying fungicides. 
Rust pustules on underside of daylily leaf.



Phytophthora foot rot of citrus

One sided blight of citrus typical of foot (root) rot

foot rot at graft union on navel orange tree
Phytophthora foot rot is the most frequently encountered disease on trunks of citrus trees in Louisiana. The disease is caused by a soilborne fungus, and wet conditions during the spring favor fruit rot development. Initial symptoms include water soaking of the bark that appears as a dark spot on the trunk. At first, the bark appears firm, but with age it becomes cracked an may shred as it dries. This disease is managed indirectly by managing good drainage of the planted area. Citrus trees should be planted in a well-drained area, and weeds and mulch should be avoided under the tree. Planting in raised beds with adequate drainage and pruning low hanging branches to allow air movement around the tree are the best management strategies for the homeowner.


Tuesday, April 30, 2013

Become a Master Gardener

2013 Louisiana Master Gardener Program (Greater New Orleans Area) 


The 2013 Louisiana Master Gardener Program in the Greater New Orleans Area (LMGP-GNO) is coming up--are you registered yet? The LMGP is a series of educational courses on "all things gardening" from pest management to propagation to vegetable gardening to home lawns. The classes are 3 hours in length and will surely give you applicable knowledge that will help your "green thumb" become a greener shade of green!

The Master Gardener Program, which began in the '90s, is a program that is an extension of the university. There is a lot of good information generated by scientific research at the university level, and students who go through the Master Gardener Program serve as an extension, or bridge, if you will, of this information to the public.

The schedule of topics are seen here. To find the application for the 2013 LMGP-GNO go to this link and follow the instructions carefully. The class will be held at the New Orleans Botanical Garden "Garden Study Center", which is located in City Park. The classes will be from July 30-September 24 from 9-12 (noon), on Tuesdays and Thursdays. Two out of town field trips to Burden Research Station and the Southeast Research Station in Baton Rouge and Hammond, La, respectively. For further inquiries please contact Andrew Loyd at 504-483-9471 or aloyd@agcenter.lsu.edu.





Friday, April 12, 2013

The Scoville Unit Garden at the New Orleans Botanical Garden

Louisiana cooking is known for its extra kick of heat, either by the addition of cayenne pepper in gumbo or a nice coat of hot sauce on a shrimp poboy. Peppers range in the amount of spice based on the level of capsaicin produced, which is largely dependent on the cultivar and partially dependent on the environment in which the pepper is grown. We know how hot peppers are based on word of mouth, or by trial and error, but did you know there are actually units that can estimate the level of spice that an individual pepper may yield. A garden will be put in at the New Orleans Botanical Garden in City Park in the next couple weeks that will showcase a range of peppers spanning the entirety of the Scoville scale.

What is a Scoville unit?
In 1912, Wilber Scoville developed a unit of measurement that would semi-quantify the level of heat, or concentration of capsaicin in peppers. The Scoville unit is named after the American pharmicist, and is still used today as a general unit correlating to the spiciness of a pepper. The organoleptic test is the procedure utilized to obtain the Scoville unit of peppers. In Scoville's method, a measured amount of alcohol extract of the capsaicin oil of the dried pepper is produced, after which a solution of sugar and water is added incrementally until the "heat" is just barely detectable by a panel of (usually five) tasters; the degree of dilution gives its measure on the Scoville scale. Thus a sweet pepper or a bell pepper, containing no capsaicin at all, has a Scoville rating of zero, meaning no heat detectable (http://en.wikipedia.org/wiki/Scoville_scale).


What will peppers will be in the garden?
All American Selection Bell Peppers 'Cajun Bell' and 'Orange Blaze' will be displayed on the low end of the Scoville scale, while on  the pepper spray side of the scale (see figure) we have the last three years Guiness Book of World Records world's hottest peppers, being: Ghost, Scorpion and Carolina Reaper. The Scoville Units of the peppers range from 0-1,474,000.


For more information contact Andrew Loyd at aloyd@agcenter.lsu.edu


Thursday, February 28, 2013


Basic flower gardening for warm season plants


The Basics

First things, first, bed preparation for your summer garden is the most important practice that will ensure your plant thrives. Soil specialist and cooperative extension groups throughout the country live on the motto, “Don’t guess, soil test”.  LSU AgCenter soil testing and plant analysis lab provides a routine soil testing service for a fee! Pre-stamped soil test boxes can be picked up at your local extension office or at many garden centers. These tests will allow you to know how fertile your soil is, and the results also provide recommendations for the particular crop you are interested in growing. The next step is engineering your bed by applying amendments that will enhance drainage, manage weeds and pathogens, improve soil tilth, which ultimately, creates a good environment for your plants.

To prepare your bed, remove any unwanted plants and turn your soil 6-8”; keeping in mind that there is a large weed seed bank in this soil, and turning the soil will create an optimal environment for these weeds to thrive. So when you ask yourself, “how these weeds got here?” you will know that they may have been in the soil all along. Next, you want to add a 2-4” layer of compost, rotted leaves, aged manure, composted finely ground pine bark or peat moss over the bed. The compost has many functions; it improves the soil texture, provides nutrients, but most importantly it introduces beneficial microbes into the living ecosystem, which is soil! Atop, the compost you will apply all-purpose fertilizer, such an osmocote 10-10-10, according to the label. All of these amendments should be mixed well into the existing 6-8” of native soil. If drainage is in question you can build your bed up more by adding additional organic matter and/or topsoil (or garden soil).

Plants can be purchased as seed or transplants can from your local garden center. This is where selection of plant material plays a key role. If purchasing transplants make sure you are buying pest-free plants; check the roots, making sure they are white and healthy. Avoid buying plants with roots that are brown or sloughing off, or plants that don’t’ have established root systems; could imply stressed or infected plants. Garden centers usually grow plants that are high in demand, so your selection could be limited to what people in your area want. If you want additional plants, seed can be purchased and easily started in your house. There are some great seed starter kits available at garden centers, but you can start seeds in just about anything—be creative; just make sure the containers are rinsed and sterilized before using them. Keep in mind, some plants do better when they are direct seeded into the garden, such as sunflowers.

When choosing plants, make sure you have taken a step back and perused the environment and observed key things like amount of sunlight an area gets, how much rain or water an area receives, and the growth habits of the selected plant material. Sun-loving plants require 6-8 hours of full sunlight a day to thrive, while shade-tolerant plants will grow optimally in areas that receive 2-4 hours of morning sun. Caladium tubers are a good choice for fully shaded areas, and provide great texture and color to a bed.

Transplants should not be planted too deep, but rather to a depth where the crown (or where the stem meets the root ball) is level with the soil. Bedding plants should generally be planted 8” apart, but be sure to be mindful of the particular growth habits of selected plants. Seeds of bedding plants should be sowed at a depth 2-3 times the thickness of the seed so seeds that are ¼” thick should be sowed at a depth of ¾”.  To create a beautiful bed and utilize space efficiently in your garden, bedding plants should be staggered in a diamond pattern, grouping colors and textures

Watering plants in during the early stages of growth is key in the hot summer months, but caution should be taken not to over water your garden because the environment will be conducive for pathogens and root rots. It is better to water the plants for long periods of time 2-3 times a week than to water for short periods of time often. Pine straw or hardwood mulch applied as a 2” layer will help retain moisture and suppress weed populations. Over the course of the growing season, gardens should be weeded and watered well. Watering plants with overhead irrigation will apply excess water to the foliage and flowers opening up your garden for a lot of problems such as disease and short flowering time. Soaker hoses are a good alternative and easy to use. In the heat of the summer plants should be watered often, because water is continually evapotranspirated, or sucked out of the plant.

If plants begin to show symptoms of stress or problems, don’t freak out. The key to controlling the your plant health issues is proper diagnosis. Disease is usually observed in “hot spots” with varying degrees of symptoms in plants, while nutrient deficiencies or water logging will be widespread and throughout. If the problem is poorly diagnosed, you will spend a lot of time scratching your head while your plants continue to suffer. You can contact your county cooperative extension agent for questions on plant health problems.


The art within the science

Plants can be planted for all sorts of functions. In regard to landscape design, the first place to start is a functional design. What “functional” plants or groups of plants do you want in certain areas? We will assume that everyone wants beautiful colors. Color isn’t the only functional type of plant. We also want to look at texture, wildlife attraction (i.e. butterflies), shape, and level of maintenance.

It is better to group colors and textures together within a bed than to plant many colors and textures in one bed. The human eye will be drawn to beautiful color that is embellished with fantastic textures. Planting “drifts” of colors, meaning groups of different harmonious colors will create a more profound product. This is the art in gardening. Every eye will want something different, which is good because it makes each garden unique and interesting. I like to think that gardening is an art within the boundaries of science. We always have to understand the biology of the plants that we work with, and with maintaining the environment optimal for the plant the application of art will make your bed unique and beautiful.

Happy Gardening!

For more information on plant selection for color, be sure and sign up for the workshop entitled “Color in the Landscape” taught by NOBG horticulturalist Melinda Taylor. (Details below)
Tuesday March 26th, 6:30 p.m. - 7:30 p.m. “Color in the Landscape”
Melinda Taylor is the color expert at the New Orleans Botanical Garden. She will talk to you about how to make fantastic containers as well as the use of color in your landscape. $10
To register: Call Susan Capley at 504-483-9473 or email scapley@nocp.org







Friday, February 15, 2013

Vegetable Workshop: for parents and teachers


See the latest news from LSU AgCenter Communications at www.LSUAgCenter.com.

02/08/13
AgCenter schedules vegetable workshops for parents, teachers
Writer: Pamela Hodson at 225-763-3990 or phodson@agctr.lsu.edu

BATON ROUGE, La. – The LSU AgCenter Botanic Gardens at Burden is holding a series of vegetable workshops on a variety of gardening topics beginning in February.

The workshops will provide information to help parents and teachers establish and maintain a vegetable garden.

“Gardens at school or home provide environments for effective learning,” said LSU AgCenter gardening specialist Kiki Fontenot. “The workshops will provide gardening basics that parents or teachers can use to plant seeds of knowledge in children.”

“The workshops will include hands-on activities, and everyone attending will be getting their hands dirty while learning basic principles of gardening that can be applied in the home or school garden,” director of education at the Botanic Gardens Kyle Huffstickler said.

The workshop dates and topics include:

– February 21 – How to construct raised vegetable garden beds.
– April 11 – Starting and growing your own vegetable transplants.
– June 13 – What is a weed, what is a plant?
– August 8 – Insect identification.
– October 10 – Is it ready to harvest/eat?
– November 14 – Preparing your fresh vegetables.

All workshops will be held at LSU AgCenter Botanic Gardens at Burden, located at 4560 Essen Lane in Baton Rouge from 6 p.m. until 7 pm. There is no charge for admission, but registration is required by contacting Huffstickler at 225-763-3990.

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Kyle Huffstickler can be reached at 225-763-3990 or khuffstickler@agcenter.lsu.edu
KiKi Fontenot can be reached at 225-578-2417 or kkfontenot@agcenter.lsu.edu