Native as well as introduced tree species face a host of alien pests and many environmental challenges in Hawaii. New insect pests, diseases and other plant problems are imported regularly. Staying current on diagnosing plant problems, being able to identify causes and control the issues is important if you are to help keep our trees healthy.
Several organizations have put together a full-day workshop for those interested in tree health for Hawaii. The Aloha Arborist Association and the Western Chapter of the International Society of Arboriculture have joined with Maui Green &Beautiful (formerly Maui Outdoor Circle), Kauai Landscape Industry Council, Hawaii Island Landscape Association and the University of Hawaii Cooperative Extension Service to bring speakers, presentations and hands-on experiences relating to Hawaii’s unique trees and pests to four Hawaii locations. One in West Hawaii is scheduled for this Friday.
The workshop will cover many aspects of tree health, starting with basic tree biology that can help our understanding of how to protect trees against potential insect, disease or environmental damage. In depth information on insect pests that threaten woody plants and palms in Hawaii will also be offered. The pest identification will include a chance for field identification. Some hand lenses will be available for sale, but attendees who have magnifiers are encouraged to bring them.
The diagnostic process, as well as helpful cultural practices and some control techniques will also be covered. Selecting the most appropriate trees for a site will be emphasized as one of the best pest management practices.
The keynote speaker is Bruce Hagen from Sebastopol, Calif. Hagen is editor for Western Arborist, the publication for the Western Chapter of the International Society of Arboriculture. The association and its magazine serve WCISA members involved in arboriculture, urban forestry and the tree care industry in Arizona, California, Hawaii and Nevada. Hagen brings a wide range of knowledge and experience to his presentations.
Joining Hagen, two women from UH will give presentations on pests and their control in Hawaii.
Susan Cabral, who is based at UH-Manoa, serves on the College of Tropical Agiculture and Human Resources staff in entomology research support. Ruth Niino-DuPonte, also from UH-Manoa, works in technical support and will add information on local insect pests. These three are scheduled to speak before noon at the conference.
A hands-on field pest identification will follow the lunch that is included in the registration fee. The three experts will assist in the collection and identification process. Hagen will close the workshop with a talk on diagnosing problems in Hawaii’s trees. Attendance at the entire workshop can qualify participants for Continuing Education Units in several fields. Six units are available for ISA certified arborist and certified tree workers as well as Landscape Industry Certified Technicians (LICT or CLT graduates). Restricted Use Pesticide Applicators can receive four CEUs as approved by the Hawaii Department of Agriculture.
This learning opportunity for anyone interested in tree health in Hawaii will take place in the Queen’s MarketPlace meeting room starting at 7:30 a.m. Friday. The meeting room is on the second floor adjacent to Sansei Restaurant, at the mountain end of the complex where close by parking is available behind the shopping center. The workshop is planned to run until 4 pm.
A complete schedule of the event is available at wcisa.net/meetings/meetingdisplay.aspx?MeetingID=5565. The cost of the workshop for members of WCISA or a partner organization is $105. The nonmember fee is $130. A special rate of $55 is available for WCISA student members or seniors by contacting WCISA Executive Director Rose Epperson in Porterville, Calif., at 559-784-8733 or repperson@wcisa.net. Walk-in registrations will be accepted at the door on a space available basis.
Tropical gardening helpline
Dorothy asks: I found some of this fruit growing on vines on my property. What is it and is it useful or shall I take it out?
Answer: The fruit in your photograph is bitter melon or bitter gourd (Momordica charantia) and is in the Curcubit family. It is a viney weed that can become invasive since it obviously has lots of seeds to create new plants as you can see. The fruit is edible but very bitter.
It grows on herbaceous vines with tendrils and climbs over walls, bushes and trees, sometimes obliterating sunlight from the plants it covers. The fruit has a bumpy rind and an oblong shape. It is usually eaten when it is green or just beginning to turn yellow. At this point it has a crunchy and watery texture and is quite bitter. The seeds are white in young fruit but are not intensely bitter. As the fruit ripens, the rind becomes tougher and too bitter to eat. The seeds, however, sweeten as they ripen to red and can be eaten raw or used in salads. When fully ripe the fruit splits and exposes the bright red seeds and pulp.
The seeds are viable when they drop on the ground or are eaten by birds and carried to other locations and germinate quickly. Unless you want to cultivate some of the vines and eat the fruit, you should probably pull out the plants by the roots and collect all the fruit and dispose of it so that the seeds are destroyed to prevent them from starting a new generation of bitter fruit, perhaps in an unwanted place.
Email plant questions to konamg@ctahr.hawaii.edu for answers by certified master gardeners. Some questions will be chosen for inclusion in this column.
Diana Duff is a plant adviser, educator and consultant living on an organic farm in Captain Cook.