Development of Organic Hop Production in the Pacific Northwest

Project Overview

Project Type: Research and Education
Funds awarded in 2009: $123,465.00
Projected End Date: 12/31/2012
Region: Western
State: Washington
Principal Investigator:
Dr. Kevin Murphy
Washington State University

Annual Reports


  • Agronomic: hops


  • Production Systems: organic agriculture


    As Proposed

    Seventy-five percent of the hops produced in the U.S. are grown on 28,000 acres by approximately 65 farmers in the Yakima Valley of Washington State. Oregon represents another approximately 15% of the U.S. hop acreage. Hops are a perennial high-value crop that, under current production standards, requires large quantities of pesticides and nitrogen fertilizer to achieve high yields and good quality. In response to increasing demand for organic hops and the rising costs of fertilizer and crop protection chemicals, hop growers in the Pacific Northwest have begun to plant organic hops. Hop yields, however, often show dramatic decreases under organic or low-input management due to increased insect and disease pressure. Research in low-input and organic systems is needed to identify suitable hop cultivars and evaluate the ability of cover crops to suppress weeds, build soil quality, supplement nitrogen, provide habitat for beneficial insects and optimize nitrogen fertility and irrigation management. The tasks of this project include: 1) evaluate hop varieties in organic and low-input systems for insect (aphids and mites) and disease (powdery and downy mildew) resistance, cone quality and yield; 2) evaluate different in- and between-row cover crop options to enhance soil fertility, enhance weed suppression and provide habitat for beneficial insects; and 3) develop an educational handbook for hop growers that focuses on sustainable hop production.

    Field trials focusing on hop agronomy and varietal selection will occur on certified organic ground on several cooperator farms in Washington State. These field trials emphasize a whole systems approach that includes the use of cover crops, intercrops, fertility and irrigation treatments, beneficial insect monitoring and diverse hop varieties to optimize hop cone yield and quality while suppressing weeds, disease and detrimental insects. We anticipate that results from this trial will have positive short-range outcomes, including the identification of varieties that perform well in organic systems and the increase in producer familiarity with and knowledge about sustainable hop production. Medium-range outcomes will be evaluated through the successful development of integrated hop farms, a change in acreage of organic hop production and a documented exchange of chemical usage in conventional hop production for biological disease and insect control methods. Field days will complement trade, extension, online and academic journal publications in an effort to reach the maximum number of producers, extension, researchers and industry professionals. This project was conceived and designed by PNW hop farmers in close communication with Washington State University researchers and extension personnel. Significantly, the hop growers in the area intend to use portions of this research on their conventional ground to reduce inputs in their quest toward regional agricultural sustainability. This project offers a multi-institutional, multi-state team of farmers, scientists and extension specialists the opportunity to improve the production of low-input and organically grown hops.

    After Implementation

    The demand for organically grown hops represents a small, but increasing, amount of total hop (Humulus lupulus L.) demand in the United States. This is due in part to legislation recently passed by the National Organic Standards Board which, as of January 2013, requires certified organic hops to be used in beer labeled organic. Hops, like many crops, face greater challenges when grown under organic practices. High nitrogen requirements, along with disease, weed and pest pressure all contribute to these challenges. Cover crops are an important component of aiding in weed control and increasing soil quality in organic production of many annual and perennial crops, but little research has investigated the use of cover crops in organic hop production. The objective of this study was to evaluate different cover crop treatments for their ability to suppress weeds and alter the weed populations within a certified organic hopyard in the Yakima Valley of Washington State. The experiment examined seven different interrow cover crop and tillage strategies against a control of existing vegetation to determine their effect on weed populations. A split-plot design with three replicates was used. The design included four hop variety treatments and eight total groundcover treatments. The response to different groundcover management strategies were examined for biomass, plant density and percent groundcover for both cover crops and weeds in the interrows of the hopyard. Cover crop treatment varied in their effect on weed biomass, weed plant density and groundcover. The control treatment consistently had among the highest weed biomass, weed plant density and percent groundcover by weeds than that of the applied cover crop or tillage strategies. Groundcover treatment had no effect on hop yield. Results indicate that cover cropping systems are a viable strategy for assisting with the control and management of groundcover within an organic hopyard.

    Project objectives:

    1. Formalize an advisory committee of organic and low-input hop growers and establish grower roundtable discussions in Washington State.
    2. Identify high quality hop varieties optimally adapted to low-input and organic production systems.
    3. Evaluate in-row cover crops for weed suppression, disease and insect control, fertility enhancement, creation of beneficial insect habitat and positive varietal interactions.
    4. Evaluate drive-row intercrops for fertility management, beneficial insect attractants, impacts on disease and insect pressure, drought resistance and soil quality effects.
    5. Conduct effective outreach through field days on growers' fields in Washington and publication of results in a wide range of media.
    6. Develop an educational product for growers focusing on organic, low-input, biologically diverse hop production.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.