WSU Tree Fruit Research & Extension Center

Tree Fruit Research & Extension Center

Saturday, January 19, 2019


Washington State University's Tree Fruit Research and Extension Center is well situated to meet the immediate and future needs of Washington's fruit industry.

  • A multi-disciplinary team integrates knowledge and expertise to solve complex biological and ecological issues in agricultural production and environmental stewardship.
  • The faculty and staff develop new information as well as focus existing knowledge and technology on local, state, and regional problems of agricultural and urban ecosystems.
  • They also provide unbiased evaluations of technology and implement it to protect the environment.
  • The Center has physical facilities (laboratories, greenhouses, research farms, etc.) designed for both applied and basic science.
  • The Center's geographic location is strategic to fulfilling the University's Land Grant Mission in most regions of the state.

The Center, created in 1937, has a long history of meeting the needs of the tree fruit industry and played a key role in its success.

The impact of research and education are sometimes overlooked, and the payoff in the investment the state and fruit industry has made in the Center. Below are selected examples of the Center's impact.


Integrated  Mite Management

has saved Washington growers $90 million in pesticide costs since 1970.

Established in 1969 by Dr. Stan Hoyt, Integrated Mite Management combines chemical control of pests with biological control of spider mites. Because of this practice most apple growers do not apply miticides to control spider mites. WSU-TFREC continues to screen new insecticides not recommending those that kill predatory mites. Info...

Biological control of Leafminers

is effective in 75% of the apple acreage, saving growers more than $2 million per year in insecticides sprays, which also had the potential to kill predatory mites.

Western tentiform leafminer became a serious pest in the 1980s when high populations reduced fruit size and quality. Research at the WSU-TFREC demonstrated the value of a parasitic wasp in controlling this pest and produced sampling plans and treatment thresholds for growers to assist in maximizing the parasite's activities. Info...

Orchard Design

using tall spindle, one of the simplest and cheapest systems, is the best for Washington conditions

Dr. Bruce Barritt's research based upon data on apple yield and fruit quality over several years has provided Washington apple growers the knowledge base to make informed decisions on how to most efficiently plant the modern apple orchard.

Pheromone Mating Disruption

allows for a reduction in broad-spectrum insecticide use of up to 70% while at the same time reducing crop losses.

The use of pheromones as a control for codling moth, the key pest in apple production, has been in large part due to efforts at WSU-TFREC. In 2008 growers used pheromones on approximately 80% of Washington's apple acreage (120,000 acres). The resultant reduction in pesticide use makes the orchard safer for farm workers and lessens risks to the environment from apple pest control practices.

Cherry  Fruit Fly Model

saves growers anually $200,000 and, possibly more importantly, it represents a reduction in pesticide use because of better timing.

The cherry fruit fly model to predict emergence of the key pest of cherry helps growers to know precisely when to begin to apply protective insecticides. The model was developed in 1991 and, based on information from Tim Smith, Chelan County Extension Pest Management Agent, it has saved growers at least one spray per year. Info...

Apple Sunburn


prevention has the potential to save $50 million annually for Washington State.

Losses due to sunburn in Washington State are typically 8 to 12% of the crop. Dr. Larry Schrader's research has identified three types of sunburn in apple (necrosis, browning, and what's called Type 3), and their causes. A chemical protectant, RAYNOX, that decreases sunburn about 50% was developed in Schrader's lab, and was successfully commercialized during 2003 in Washington State. Info...

Orchard Soil Arsenic Contamination

may pose risks to human health. Approximately 677,000 acres of land are contaminated with lead and arsenic in Washington State, of which 188,000 acres are old orchard soils.

Arsenic-containing compounds were the most commonly used insecticides during the first half of the 20th Century leaving many agricultural soils with residues of lead arsenate and other arsenical pesticides. Dr. Frank Peryea’s research program examines the biogeochemistry and management of lead and arsenic in contaminated soils, and has been used in Washington state guidelines for addressing area-wide contamination. Info...

Tree Fruit Research & Extension Center, 1100 N Western Ave, Washington State University, Wenatchee WA 98801, 509-663-8181, Contact Us