Past Projects


Demonstration of tree selection and silviculture to optimize restoration success with koa (Acacia koa)

A new extension project will demonstrate increased koa growth and productivity gained from planting selected koa trees using the best silvicultural practices. We will establish accessible demonstration plantations and develop a practical user-guide.

Psyllid Study

Can control of acacia psyllids reduce the formation of multiple stems on koa saplings?

We hope to discover whether controlling acacia psyllids can reduce the amount of forking in koa seedlings. If so, this may be a silvicultural solution for growing single-stemmed trees that could someday be made into traditional canoes.

Psyllid Study

Acacia koa gene expression along elevation and precipitation gradients

Successful reforestation of native Hawaiian forests requires using genetically appropriate seed sources. This study aims to identify the genetic adaptations of koa trees to environmental conditions in different ecosystems in Hawaii.

Psyllid Study

Effects of koa moth defoliation on Acacia koa plantations

This study will help us to better understand the effects of the koa moth, Scotorythra paludicola, how long it takes for a koa stand to fully recover, and to expand the knowledge about koa stand dynamics.

Wilt Resistant Acacia Koa

Developing wilt resistant Acacia koa for Hawaii

Research developments from the Hawaii Agriculture Research Center to develop koa varieties resistant to the deadly koa wilt disease.


Acacia koa pollination biology and genetic markers for koa wilt resistance

Cross-pollination of koa flowers to develop population of known parentage for studying koa wilt genetic markers at the University of Hawaii.


Parent tree selection and wood quality of a 9-year-old Acacia koa stand

Research on the genetics of koa growth, form, and wood quality by Purdue University graduate student.


Caterpillar outbreak hits Hawaii Island forests

Information on the recent outbreak of native koa looper moth from the Division of Forestry and Wildlife.


Subirrigation as an innovative new technology to reduce water consumption for native plant nursery production

Purdue University silvicultural experts working with local nurseries to develop new techniques to produce better koa seedlings.

A delay in leaf form transition as a shade avoidance response in two populations of Hawaiian Acacia koa from contrasting environments

New research project to understand phenotypic plasticity and adaptation of koa trees by Purdue graduate student.
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