The Daily Southerner, Tarboro, NC

March 15, 2013

"Ask A Master Gardener"

"Ask A Master Gardener"
FOR THE DAILY SOUTHERNER

TARBORO — Buddy H. (Tarboro) asks: I discovered this unusual substance wrapping the stems on all of my compacta holly when I was pruning them last week.



Answer: We have identified this to be "FELT FUNGUS," Septobasidium — it is brown, soft, leathery, felt-like perennial, lichen-like in appearance and may frequently surround small tree branches. Species of this genus are usually on trees and associate with scale insects. The fungus is superficial on the plant, but parasitizes the insects which are feeding on the plant host.  Within the fungal thallus is a labyrinth of tunnels and chambers.

Each chamber contains a single scale insect directly in contact with the tree bark. Tunnels open to the surface. Septobasidium may involve entire colonies of scale insects whereas other genera of felt fungi parasitize single insects.



Insects act as sole agents of fungus dispersal. They also feed on medullary, ray cells in the woody tissues of their host plant. Nutrients are then assimilated from their blood by fungal hyphae. In nature, Septobasidium burtii is obligately associated with scale insects.  



Damage to the plant has been attributed to certain species of Septobasidium; however, it is probable that this damage is due to the activity of feeding insects, not direct parasitism of the plant host by the fungus.



If warranted, control may be achieved by pruning affected branches and spraying with a copper fungicide as a preventative.



Debra P. (Tarboro) asks: What is a good way to control grass and weeds around my grapevines?



Answer: Grape Vines are sensitive to weed killers and herbicides but because the grapes are eaten, great care must be taken to ensure safe application of any chemicals. Weed control helps to prevent soil moisture and nutrient loss at the base of the vines. Limiting competition from weeds is more important in drought conditions. Most effective control methods use herbicides along with cultural and mechanical strategies. No one herbicide will control every type of weed so treatments are targeted to the species and often combined in staged applications.



Pre-Emergent Herbicides

• Preemergent herbicides are applied to the raw soil in the late

winter or early spring well before grape vine buds break through. These halt the growth of weed seeds that are not yet germinated. Application methods and doses vary by brand, but most are incorporated into the soil and then irrigated or applied during rain. Some safe grape vine herbicides are Napropamid, Ortyzalin, Oxyfluorfen and Glufosinate.

Post-Emergent Herbicides

• Postemergent herbicides are applied to the weeds and the

immediate surrounding soil to kill the weed plant itself. These are often applied in limited spot treatments during the growing season and more broadly during times of vine dormancy. Some common grape vine safe postemergent herbicides are Simazine, Diuron, Norfurazon and Dichlobenil.



Read more:

 HYPERLINK "http://www.ehow.com/way_5208785_weed-killer-grape-vines_.html#ixzz2NQjSn7M9" http://www.ehow.com/way_5208785_weed-killer-grape-vines_.html#ixzz2NQjSn7M9



What Is the Best Weed Killer for Grape Vines?

http://www.ehow.com/way_5208785_weed-killer-grape-vines_.html#ixzz2NQjSn7M9



Nancy H.(Tarboro) asks: What is causing the leaves on my camellia to yellow?



Answer: Tea scale is an insect that causes leaf yellow that matches your description.  Tea scale has been reported on camellias throughout the Deep South (and in California). It probably originated in southeast Asia. In the Southeast, tea scale is a serious pest of camellias as well as Chinese and Japanese  ( HYPERLINK "http://ipm.ncsu.edu/photogallery/tscale5.jpg" http://ipm.ncsu.edu/photogallery/tscale5.jpg) hollies. It has

also been reported on bottlebrush, dogwood, ferns, euonymus, mango, Satsuma orange, tea plant, orchids, and yaupon.

Tea scales occur primarily on the (http://www.ces.ncsu.edu/depts/ent/notes/O&T/shrubs/note50/teascaleunder.jpg) undersides of leaves. The most conspicuous characteristic of an infested plant is (http://www.ces.ncsu.edu/depts/ent/notes/O&T/shrubs/note50/teascaletop.jpg) yellow splotching on the upper leaf surfaces, an effect of feeding insects underneath. The whole plant may appear unhealthy, and the leaves drop prematurely. The number of blooms decreases or cuttings may die before roots develop.  



Learn more at: http://www.ces.ncsu.edu/depts/ent/notes/O&T/shrubs/note50/note50.html



Treatment:

Various oils have been used for centuries to control insect and mite pests. Oils remain an important tool to manage certain pest problems (e.g., scales, aphids, mites) on fruit trees, shade trees and woody ornamental plants.

Several recently developed oils extend this usefulness to flowers,

vegetables and other herbaceous plants. Oils also can control some plant diseases, such as powdery mildew. Oils used to protect plants have been called by many names, but perhaps horticultural oils best describes them. Find them at your favorite garden center.

Horticultural oils pose few risks to people or to most desirable species, including beneficial natural enemies of insect pests. This allows oils to integrate well with biological controls. Toxicity is minimal, at least compared to alternative pesticides, and oils quickly dissipate through evaporation, leaving little residue. Oils also are easy to apply with existing spray equipment and can be mixed with many other pesticides to extend their performance.  



Learn more at: http://www.ext.colostate.edu/pubs/insect/05569.pdf



"Ask A Master Gardener" is a weekly column providing our readers solutions to common problems concerning horticulture, gardening, and pest management. Trained Extension Master Gardener Volunteers have access to the research that provides answers.  



Submit your questions by email to: askemgv@gmail.com. Or call the local Extension Center at 641-7815 and tell them you have a question for a master gardener; a volunteer will return

your call with a solution to your problem, or write to "Ask A Master

Gardener", c/o The Daily Southerner, P.O. Box 1199, Tarboro, 27886.