Archive for July, 2013

Spittle Bugs – the Mystery Foam Source

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Spittle Bugs – the Mystery Foam Source

By George Giltner, Master Gardener

two lined spittle bug

Two lined Spittle bug (Prosapia bicincta), Clemson University Coop Extension Service photos

spittle

Spittle (bubbly froth mass with larvae), Clemson University Coop Extension Service photos

From the name, spittle, you know what to look for – a spit-looking mass on vegetation.  This frothy mass is excreted by yellow-brown nymphs mainly on grasses and ornamentals as defensive protection against predators and desiccation.  Below the froth, the nymphs insert piercing mouth parts into the plant consuming large amounts of plant juices.  They go through 4 instars before reaching adulthood.  Populations expand during wet humid climate periods and retract during drought.

In Louisiana, they can be found on grasses like St. Augustine, centipede, rye, Johnson, coastal Bermuda, and small grain crops.  Usually spittle bugs are not a problem, unless large populations develop under wet environmental conditions.  Pyrethroids can be used for control.  Also look for them in vines like honeysuckle and morning-glory and in ornamentals like holly, aster, and redbud where their feeding results in white blotches on the leaves.  They are most active in the morning to avoid the heat and drying conditions of hot afternoons.

The common two-lined spittle bug adults look like large black leafhoppers.  They are easily identified with two large red or orange stripes across their triangular-shaped body.  If you get close enough, notice the small red eyes.

The adults only live for three weeks, with females laying eggs during the last two weeks of their lives.  Eggs laid in the fall, overwinter in grass sheaths and ground debris.

The Pecan spittlebugs, Clastoptera achatina, are more of a problem insect, especially where pecans are grown.  The nymphs become active after bud break in the spring by feeding on young buds and later on tender shoots and nutlets.  Heavy populations can cause terminal bud death and immature nut shedding.  Infections can be recognized by white bubbly masses on terminal buds to dried yellowish masses on young nuts.  The adults are small, 4 to 5 mm, and yellowish brown in color.  Therefore they are hard to detect in pecan trees.

So the next time that you see those frothy masses on your plants, shrubs or trees, look for the larvae spittlebugs underneath.  At least you will know the source was not a rabid animal or from human origin.

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Unique Educational Opportunity in Central Louisiana

Unique Educational Opportunity in Central Louisiana

            Educational training for the second largest industry in Louisiana is offered right here in central Louisiana. The specialized forest technology degree was instituted in 1976 at the Oakdale Campus (117 Highway 1152) of Central Louisiana Technical Community College in Allen Parish and continues to prepare students to work in the forest industry at the technician level. The program is 18 to 24 months and features classroom instruction coupled with significant hands-on (60%) training, labs and field trips. The opportunity for internships and work-based partnerships are presently in development.

            CLTCC Forestry is accredited by the Council on Occupational Education and is monitored by an advisory committee composed of forestry professionals from private industry, government, and forestry related support organizations. Courses in the program include Dendrology (tree identification), forest surveying, GPS/GIS applications, forest fire protection, and prescribed burning, insect and disease control, wildlife management, forest harvesting, and forest products.

Graduates are employed throughout Louisiana and beyond for both private industry and government agencies. Forest technicians are still in demand and the CLTCC Forestry Technology Program is a broad-based, comprehensive curriculum that can provide students with the skills to address the needs of the forest industry.

For more information on this program call: Brian Thompson at (318)335-3944 ext. 3118,

Email: brian.thompson@cltc.edu, or go to www.cltc.edu

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Boost Soil Health for Great Gardens

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Boost Soil Health for Great Gardens

By George Giltner, Advanced Master Gardener

How do you improve soil health?  Simply, manage the life in the soil.  It is just like growing grazing animals, however the life forms are much smaller.  You need air, water, food, a suitable temperature, and certain other environmental factors that favor their growth.

Air, yes the soil needs to breath.  Gases must be able to freely move through the soil for healthy soil.  A good healthy soil is fluffy and light with aggregates that are formed from fungal glomalin, the “super glue” of soil.  This mycorrhizal glue accounts for 27% of the carbon in the soil which may last up to 40 years.  It provides soil structure to harbor beneficial microbes, retain water, and reduces soil compaction.  The mycorrhizae form mutualistic relationships with plants in which nutrients and water is transported.  Therefore the gardener or farmer would want to encourage this fungal growth.

The best way to encourage mycorrhizal growth is with no-till practices.  Tilling or plowing chops up the fine mycelial strands between the plant and surrounding soil which is detrimental to fungi and plant.  Cover crops (especially mixed plant types), less use of cabbage and mustard family plants that do not use mycorrhizae, and less phosphorus applications will result in favorable conditions for glomalin-producing fungi.

Know your water!  Check the pH of the water that you are irrigating with.  Some regions have major problems sodium carbonates and bicarbonates which raise the pH up to the high 8’s and even above a 9 pH which is above EPA waste water limits.  This can cause soil compaction, reduced plant grow, and salting of the soil.  Also use a water meter to test soil moisture instead of guessing.  Sometimes we become very busy, so use drip irrigation on a timer as the best way to control watering.

The soil needs to be fed.  Composted animal manure to a plant is like giving steak to a starving teenager.  The mineral and organic nutrients of good compost enhance the soil growth of bacteria to worms to soil arthropods. Each time these critters poop or die, their wastes become available as nutrients to plants and other organisms of the soil.  Cover crops are another major food source of the soil.  As these crops grow, they provide exudates of carbohydrates that feed beneficial microbes around their root systems.  This activity initiates a soil food chain.  Also crop residues are also beneficial to decomposers in the soil.  The soil should never be without food (some organic matter to feed on).  Yet some people leave the soil bare for months until spring, but by then most of the soil life has starved or moved.

Soil temperatures will affect microbial populations.  Summer temperatures on bare ground can exceed 120 deg. F.  With this heat extreme, plants and soil literally have the moisture and life cooked out.  Photosynthesis goes downhill at 95 deg. F.  In order to cool this heat environment, add a two inch mulch insulation layer to reduce soil temperature 20 to 30 deg. F.  Another approach is to have multiple layers of leaf height to shade the soil from all angles.  This will result in a 20 degree cooler soil.

The secret of good soil is to treat it like a living organism.  As it grows – so does your plants.

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Soil Fertility Factors

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Soil Fertility Factors

By George Giltner, Advanced Master Gardener

You don’t have to battle through botany, chemistry, cellular biology and physics to understand that when essential nutrients are not available to plants, they will not grow.  Common garden logic is in the “Law of Return”.  When plants are removed from a garden, along with them goes a portion of the nutrients in the soil.  Therefore the gardener must return that complement of nutrients in the form of fertilizer back into the soil to maintain its fertility.  Other nutrient-loss factors like water leaching, volatile gases lost in decay, pest grazing, mineral insolubility, even removing weeds, and others contribute to fertility losses.

Soil testing can identify these losses.  Also soil test results supply information on soil mineral corrections.  Soil test sample boxes are available in a convenient mail-in form that can be obtained from the AgCenter.  Results are usually emailed or mailed within a week.

Organic matter additions are an excellent means returning nutrients and minerals back to the soil.  Consider making compost year round for garden amendments.  The compost is important to the soil structure, the microbes to insects in the soil-food web, moisture and mineral retention, and to the environment.  Mineral fertilizers do return mineral nutrients quickly to the soil, but it is in a leachable form that is destructive to soil life and the long term detriment of soil fertility.  Organic fertilizers provide a wide range of macro and micro nutrients that chemical fertilizers do not have.

Plant nutrient intake is influenced by temperature, mainly from 42 to 95 deg F for most plants, due to limits on photosynthesis and microbial produced nitrogen.   Also mycorrhizal fungi are very important for most of plant’s phosphorus uptake.  During early spring, one may notice purple leaves on tomatoes exposed to cool temperature soils.  This is probably due to lack of phosphorus transport activity of the fungi due to cool temperatures.  In summer, exposed soil around plants can reach temperatures around 120 deg F, thus limiting photosynthesis.  Mulching can reduce these temperatures by a significant 30 degrees, thus allowing for moderate temperatures for photosynthesis.

Problems with pH are typical with chemical gardeners.  Additions of ammonium are converted to nitrates by nitrogen-fixing soil bacteria, resulting in a lowering of the soil pH.  As the soil pH goes more acid, less and less of soil minerals are available to plants.  If lime is added during the plant growth cycle, “lime shock” occurs which leads to further problems with nitrogen loss, and a lock up of phosphorus in insoluble (unavailable) calcium phosphate.  Plant microbes are affected and other minerals become unavailable for plant absorption.  With a healthy organic soil, plants synthesize and release exudates that adjust the pH through action of the microbiological community.  Therefore organic soils are much less pH complicated to the gardener.

Poor soil aeration can devastate beneficial microbes in soils.  A compacted soil results in trapped carbon dioxide reacting with water to form carbonic acid. Excess carbonic acid then reacts with organic matter to form deadly alcohols and other noxious chemicals that kill root cells.  Aerobes in the soil are replaced with anaerobic life which ties up nutrients that would be going to plants.  Organic soil will hold its loose structure even after rains, whereas mineral soils will collapse and become compacted. A fluffy soil that can allow oxygen and water to flow easily is ideal. Water and oxygen movement is necessary to maintain the microbes and to transport soluble nutrients to plant root systems.

Chemical balances influence availability of individual mineral nutrients.  There is completion among ions of minerals for absorption on root sites.  Example: If you have too much potassium, magnesium, or sodium in your soil, plants will take up less calcium.  As a result, blossom-end rot would be much more common in your tomatoes, squash, and other plants.  This is why frequent soil tests are very important to chemical gardeners, but less so to organic gardeners.

Many people want to become gardeners, especially with rising food prices, problems with food safety, and reports of lack of nutrients in food items.  Too many are taking the “modern path” by pouring on N-P-K fertilizer without knowing how the fertilizers work.  These people use three times the nitrogen that farmers use.  This results in excess nutrients (esp. nitrogen and phosphorus) that are washed into waterways and harm aquatic environments, plus their garden is a flop.  To become a responsible and knowledgeable gardener, take the Master Gardener Classes at the LSU AgCenter. For more information about Master Gardeners, call the AgCenter at 337-463-7706 or email khawkins@agcenter.lsu.edu.

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