Conifer diagnostic app is the first of the UD Pocket Farmer App series for UD Cooperative Extension. A group of students began development of the app in January, with availability expected in the Apple Store in mid-summer. See the article on UDaily: http://www.udel.edu/udaily/2015/may/pocketfarmer-app-051115.html
and on DelMarVa Morning Ag Clips:https://www.morningagclips.com/enewsletter/delmarva-edition-for-may-14-2015/
Category: Commercial Horticulture
New Invasive Insect Pest – Spotted Lanternfly
The spotted lanternfly, a poor flying but strong jumping moth-like pest that attacks grapes, apples, tree of heaven (Ailanthus), and other hosts has been found in Berks County Pennsylvania. The inch long insect is a potentially devastating pest. Please see the PA Department of Agriculture web site at: http://www.agriculture.state.pa.us/
The Spotted Lanternfly (Lycorma deliculata), an inch-long black, red and white spotted pest, is native to China, India, Japan and Vietnam. It’s an invasive species in Korea, where it has attacked 25 plant species which also grow in the U.S.. In the U.S. it has the potential to impact grape, fruit tree and logging industries. The pest attacks many hosts including grapes, apples, pines, stone fruits and more. This time of year, look for adults and egg masses on trees such as Ailanthus, and please collect samples and report any suspect finds to your local Cooperative Extension office or Delaware Department of Agriculture.
Fringe Tree Possible Host for Emerald Ash Borer
On October 14, 2014, the USDA Systematic Entomology Laboratory (SEL) at the Smithsonian confirmed partial adult and larval specimens recovered from a white fringetree (Chionanthus virginicus) as emerald ash borer (EAB) (Agrilus planipennis Fairmaire). EAB larvae and a partial adult specimen were collected from four white fringetrees up to 20 miles from one another in the Dayton, OH area. D-shaped exit holes and fully developed galleries in wood were identical to those caused by EAB.
Based on these findings, APHIS PPQ is conducting studies whether EAB is able to complete its lifecycle on white fringetree as a host, which will take several months. APHIS is also revisiting research on whether other members of the Olive family can serve as hosts of EAB and whether this is a local phenomenon. APHIS will engage national, state, and industry partners as part of the regulatory decision making process should APHIS officially declare white fringetree as an EAB host and the plant and its parts as regulated articles under the regulations, quarantine, and detection aspects of the EAB program.
White fringetree is in the olive family, as is the genus Fraxinus (ash). Other members of the olive family, including lilac and privet, were tested, and are not considered suitable hosts for EAB. Further study and evaluation of white fringetree’s suitability as a host will be undertaken. White fringetree is native to the United States and grows wild from New Jersey south to Florida and west to Oklahoma and Texas. It is a popular ornamental tree that has been planted in other parts of the country.
10/23/14 NFG
Phytophthora Resistant Plants for the Landscape
Phytophthora Resistant Plants
Phytophthora root rot, a soil borne disease caused by a fungus-like organism, is a widespread problem which can affect many woody and herbaceous landscape plants. Azalea, holly, rhododendron, and juniper are the most frequently affected plant groups in the eastern landscape. Submit a sample including roots to the Plant Diagnostic Clinic and it can be tested for Phytophthora. An infested site should not be replanted with susceptible hosts. Increase drainage and plant a more resistant shrub or tree. The best control for Phytophthora is to avoid getting it started in the first place. Phytophthora is favored by planting susceptible species and cultivars in poorly drained soils, or by overwatering in sites with adequate drainage. Once a Phytophthora problem is established in a landscape site, the best option is to remove the affected plants and replace with resistant species. Some good choices include Clethra alnifolia (summersweet), Itea sp (sweetspire), Physocarpus opufoliius (Eastern ninebark), and Leucothoe fontanesiana. Examples suggested by extension agents in North Carolina include Nandina, Chinese holly (cultivars including 'Rotunda', 'Dwarf Burford' and 'Carissa'), liriope, Indian hawthorn, and Camellia sasanqua cultivars (Camellia japonica is highly susceptible). The rhododendron hybrids: ‘Caroline’, ‘Martha Isaacson’, ‘Professor Hugo de Vries’ and ‘Red Head’ are considered resistant. In addition, the azalea cultivars 'Formosa', 'Fred Cochran', 'Fakir' and 'Corrine Murrah' are considered highly resistant. Other resistant azalea cultivars include Rhododendron poukhanese, ‘Formosa’, ‘Fakir’, ‘Corrine Murrah’, 'Merlin', 'Hampton Beauty', 'Higasa', 'Pink Gumpo' and 'Delaware Valley'. Susceptible cultivars include 'White Gumpo', 'Hinodegiri', 'Hershey Red', 'Coral Bells', 'Pink Pearl' and 'Hino Crimson'. Susceptible cultivars are the most widely planted, due to desirable horticultural characteristics. Resistant hybrids are not immune to disease, but more tolerant. Chemical control is generally not practical for the homeowner, and involves a drench or injection by a certified applicator.
NFG 10/2014
Healthy Christmas Trees Before and After
Christmas Tree Planting Tips
The lifting, storage, and transport involved in shipments of evergreen planting stock can have long lasting effects. Planting stress affects root quality, and those effects can last beyond planting and can cause plants to not recover completely. Water is probably the most important factor. The system can be thought of as keeping a checkbook. Each stress subtracts from the quality balance remaining for tree health. Some tree nurseries allow for freezer storage of seedlings that may help preserve moisture in the plants and plant roots. Plugs need different care than bare root stock. Proper planting and care to have roots set properly can avoid J root which will cause long term stress on trees.
- 2012 Gregory Diseases of Christmas Trees [presentation]
- Rick Bates PSU_2013 Christmas Tree Production and Rhabdocline Needlecast [presentation]
- Olson Delaware Christmas Tree Workshop April 23, 2013 [presentation]