The term agroforestry is a relatively new word in the English language that describes agricultural practices, such as many of those employed by Pacific Islanders for millennia. The word refers to the practice of growing trees combined with crops and/or animals in ways that create benefits from their interactions. The term agroforestry applies to food forests, shade-grown cropping, windbreaks, timber trees with livestock, trees for coastal protection, and many other practices. All of these agricultural systems can increase productivity compared with conventional agriculture. Agroforestry systems tend to have less pest and disease problems, provide natural weed control, and require less fertilizer and other outside inputs compared with conventional agriculture. They also provide long-term benefits for the soil and watershed.
Food forests are an enduring example of agroforestry. Traditional Pacific Islander’s homes are commonly surrounded by fruit, nut, timber and medicinal trees. These trees are grown together in a multilayer forest-like planting that includes annual crops and even small livestock. Often ornamental, native and lei flower plants are also included in the mix. Homegrown food forests have been called “the epitome of sustainability” by researchers, as they have provided abundantly for families over very long periods of time. Their self-sustaining productivity is still a mystery to scientists.
Shade-grown cropping is an agroforestry practice with promise for Hawaii farms. Certain crops such as coffee, cacao and vanilla benefit from moderate shade (about 30 to 40 percent) under trees. Selecting shade trees that produce high-value timber, fruit, nuts or other products diversifies crop yields and increases farm income. As a much-appreciated side benefit, growing crops under shade also makes a much more comfortable working environment for people.
Windbreaks are another popular form of agroforestry that can be used in Hawaii. Their purpose is to shelter crops, animals and structures from damaging winds. They can also mitigate airborne dust, salt spray and other pollutants. Certain fruit, nut and spice trees are suitable for use in windbreaks. With a long-term plan, even high-value timber species can be included.
The art of agroforestry is experiencing a renaissance in Hawaii because of our newfound passion for eating local food that is grown sustainably. Drawing upon the long traditions of agroforestry in the Pacific, a new workshop, “Creative Agroforestry for Food Production in Home, Farm, and Community Landscapes” will be presented at Amy B. H. Greenwell Ethnobotanical Garden in Captain Cook on June 20 and 21. The workshop brings together agroforestry expertise from around Hawaii to offer participants an introduction to best practices in agroforestry or enhance their skills in establishing and maintaining a custom-designed agroforestry landscape.
The workshop will help participants understand traditional Pacific Island, as well as modern agroforestry systems and demonstrate ways these can be adapted to Hawaii Island environments. Many local experts have been invited to speak. University of Hawaii graduate student Natalie Kurashima will discuss the unique and highly productive traditional agricultural systems of Kona. Neil Logan of FARM Center will share his decade-long experience converting pasture land to a food forest that also offers protection from trade winds. Natural methods for establishing and maintaining food-producing agroforestry landscapes will be presented by Tom Baldwin. Sara Moore, with extensive experience raising livestock, will share her experience integrating tree crops with animals. How risks for pests and diseases can be reduced in diverse agricultural systems will be presented by Dr. Hector Valenzuela of UH-Manoa. Dr. Amjad Ahmad, also from UH-Manoa, will present recent research about how locally available materials can enhance soil function, thereby replacing imported soil inputs. Finally, Laura Nelson of the USDA Natural Resources Conservation Service, will explain federal assistance programs that can be used in association with planning and implementing agroforestry systems.
The second day of the workshop will be devoted to field tours, including a Polynesian-style food forest, an award-winning agroforest that combines native Hawaiian and introduced plants, and an open pasture that has been converted to a food-producing agroforest landscape.
Participants in the workshop will receive a copy of the new book, “Agroforestry Landscapes for Pacific Islands: Creating Abundant and Resilient Food Systems.”
For more information about the workshop and for information on registration visit agroforest.info
Craig Elevitch is a local author, agricultural researcher and director of the nonprofit organization Agroforestry Net.
Tropical gardening helpline
Dan asks: Can you tell me what’s eating my ti plant and how to care for it? See the photos of my ti leaves with large ragged holes.
Answer: From looking at your photos, it is apparent that a chewing insect is feeding on your ti leaves. Although Chinese rose beetles or caterpillars (the leaf eating larval form of several insects) could be responsible, the ragged holes look more like grasshopper or katydid damage. Chinese rose beetles generally feed just after sunset. Take a flashlight and go check for them around 8 p.m. If you don’t see them you can rule them out. Caterpillars are slow moving and usually hide on the undersides of the leaves. You can rule them out if you don’t find any. Grasshoppers and katydids usually feed in the day so look for them on the leaves or see if you find any of their small black eggs tucked into the edges of leaves. If you discover a pest, knock it into a resealable plastic bag, shut it and put it in the freezer. If you can bring it in to the Master Gardener Help Desk at the Kainaliu Cooperative Extension Service on a Thursday morning between 9 a.m. and noon, we can probably provide positive ID. Emailing a photo of the pest might also work.
Once grasshoppers find a tasty food source they are hard to get rid of but you can try several things. Many birds eat grasshoppers. Put out a bird feeder near your ti plants. Grasshoppers and katydids thrive in hot, dry sunny locations. Shading your ti plants and keeping the leaves moist could discourage them. Neem products can also be effective when sprayed on the leaves. Neem will deter feeding and disrupt the development of grasshopper nymphs.
Remove as many of the damaged leaves as possible but not more than one-third of the plant’s leaves. This will eliminate the pest attractant emitted by damaged leaves and give you the opportunity to see if the pests are still present.
In the interim you might want to check a CTAHR publication that could offer some help at ctahr.hawaii.edu/oc/freepubs/pdf/of-33.pdf. Ti plant pests are listed on pages 8 through 11 with recommended control measures. The article also gives some good care and maintenance information on growing ti plants.
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.