Developing Effective Alternative Pest and Disease Management Strategies for Sustainable Hop Production

Project Overview

Project Type: Farmer/Rancher
Funds awarded in 2016: $6,472.00
Projected End Date: 01/30/2018
Grant Recipient: Wosoba Farms Hops
Region: North Central
State: Iowa
Project Coordinator:
Carla Wosoba
Wosoba Farms Hops

Annual Reports

Information Products

Field Day Brochure (Bulletin)


  • Agronomic: hops
  • Animals: poultry, sheep


  • Pest Management: biological control, field monitoring/scouting, integrated pest management
  • Soil Management: soil quality/health



    This project aims to manage hop pests and diseases without the use of commercial chemicals.

    Insects were ordered from Buglogical and released into the hop yard beginning June 4. Green Lacewings and Lady Bugs were released on this date. Nematodes were applied to the soil beginning Wednesday, June 8. I applied the nematodes again on June 28.

    I purchased 25 Red Star chicks for the project through a local hatchery, but they were not ready to be released in the hop yard until near the end of the growing season. I did not want to purchase the chicks in winter or early spring as I did not have a suitable place for them to be kept warm as chicks. Thus, an additional 40 Red Star hens were purchased from a local farm. These chickens were released into the hop yard on June 13, 2016. The hens were initially kept in a portable enclosure during the day that could be moved every 1-2 days. After they had been at the farm for two weeks, they were gradually allowed to range freely during the daylight hours. They are always housed in the coop overnight. The chickens are fed a ration of layer feed each night, and allowed to range during the day eating bugs, grass, and weeds. It did take some time for the chickens to begin to forage. They had not been free range in their original environment. I recommend purchasing chicks well in advance so they can be accustomed to foraging before you need them for pest control. I will admit that there were times in the beginning that I felt like a chicken farmer instead of a hop farmer. It took some time to train the chickens to come out of the coop in the morning and to go back in at night. It was great to have the eggs. Of course I eat some of them, but mainly I have used the eggs to barter with neighbors who have helped me out in some way with the hop farm. The chickens reduced the need for fertilizer applications around the hops as well.

    I purchased organic starter plants that would attract beneficial insects. These plants went into the ground in late May. The plants had a few weeks to establish themselves before the beneficial insects were released. Some varieties were perennials, but others were annuals that will need to be reordered for 2017. 

    Habitat for beneficial insects was increased greatly in year two. Permanent planting beds were established using old materials laying around at the farm. Large tractor tires and old wooden feedbunks were used to plant seeds and seedlings that would attract and retain beneficial insects to the hop yard. The focal plants were lavender, dill, fennel, lemon balm, and coriander. Early scouting prior to release of new insects showed large numbers of ladybugs in the yard. In previous years, we just were not seeing the beneficial insects in the hop yard.

    Before the release of insects and chickens, there was noticeable pest damage on the young hop leaves. I determined the damage at that time, in May, had come from hop flea beetles. Within a week of releasing the beneficial insects, hardly any flea beetles could be found in the field. By the end of June, the plants had healthy new leaf growth. All of the hop flea beetles were gone. The ladybugs were prevalent throughout the hop yard.

    Japanese beetles began to arrive in the hop yard in late July. At first there were only a few, and they were monitored closely. It was difficult to find beneficial insects that would have an impact on Japanese beetle populations. Applying beneficial nematodes may have helped to limit the larvae in the yard, but it is difficult to tell. Any Japanese beetle pheromones will attract more beetles, so it’s hard to tell if they came from other locations. Beneficial nematodes are rather expensive, so more closely monitored data collection is necessary to determine their effect before drawing conclusions.

    The chickens did have an impact on the Japanese beetles. However, most of the beetles stayed high enough on the plants that the chickens were unable to reach them. When the bugs were knocked off the plants by a person, the chickens would eat them immediately. Next year, I will apply soapy water with a sprayer to knock the beetles to the ground. This will make it easier for the chickens to do their work. Several plants did sustain significant beetle damage to the leaves. However, the beetles did not damage the delicate hop cones. It is worth noting that large populations of Japanese beetles will decimate the leaves of hop bines if left to do so. Japanese beetle populations must be monitored daily to ensure the health of plants.


    I was able to share information regarding this SARE project in several ways during year one. Wosoba Farms Hops has a Facebook page with approximately 250 viewers. Throughout the growing season, I posted pictures and project updates to share what was happening. I also post updates on Twitter for just over 120 followers to see. I was asked to speak at the November meeting of the Baldwin Women’s Club, where I shared this SARE project with 20 local women. Also in November, a local journalist joined me at the farm to hear more about growing hops in Iowa and how the SARE project can play a role in the industry. His article was published in the November issue of Country Life, and was read by some 9,250 subscribers.

    WORK PLAN FOR 2017

    There were a lot of things happening with this project in the first year, and year two of the project will be even more eventful! I have plans to improve this project in year two, and I feel confident that I will continue to see results.

    I plan to release the same numbers of beneficial insects, this time about two weeks earlier. I also plan to use a much larger number of attractant plants to provide habitat for the beneficial insects so that the plants are surrounding the entire row of hop plants that are part of this project. In late June, another application of beneficial insects may be necessary as well to be sure that populations remain strong throughout the hops.

    The chickens will begin their work in the hop yard much earlier in 2017. Depending upon the growth of the bines, the chickens may be released as early as May 1. Once the bines have begun to thicken around the crown of each plant, they will be able to withstand the foraging of sheep. I expect this to happen in late June or early July, allowing for the sheep to be introduced into the project. The sheep will be allowed to graze in and around the hops using a portable fence. This enclosure will be moved as needed to ensure that the sheep have enough to eat but are not overgrazing. Soil sampling will be done to monitor nutrients and determine additional fertilizer needs. Insect traps will be used throughout the hops to monitor populations of both pests and beneficial insects, as well as regular scouting of the field.

    In July, I will host a field day at the farm and invite the public to see this project in action. I also plan to continue working with Lowell Carlson, local journalist, who has asked if he could follow me during the project. I will work with a filmmaker to create a short documentary of the SARE project using photo and video clips collected throughout years one and two. I am excited to share the outcome of my work with SARE, and hope that the results of my project will benefit other hop growers who wish to grow a quality product without the use of harmful chemicals.


    Project objectives:

    Herbs and flowering plants that attract beneficial insects will be introduced around the entire row of hops. These plants will keep the good bugs in the hop yard by providing shelter and additional food. It is important to have plants that flower at various times throughout spring, summer, and fall. Dill, caraway, fennel, coriander, Queen Anne’s Lace, lavender, parsley, lemon balm, and zinnia will be planted each spring. Lacewings, ladybugs, hoverflies, parasitic mini-wasps, and tachinid flies will then be released into the hop yard. These insects will feed on the hop pests as well as their larvae and eggs.  The combination of insects and plants will keep the beneficial insects coming back to the hop yard in future years.

    Chickens will be introduced into the hop yard in the first year of the grant. Chickens eat grasshoppers and other flying insects while scratching the soil to improve airflow between plants.  They also provide fertilizer and aeration.  I am using a cover crop of alfalfa in between all rows to improve nitrogen levels, help minimize weeds, and control erosion. In the second year of the project (year 3 in the life of the plants), I will introduce sheep to the hop yard. The sheep, like the chickens, will fertilize the hop yard. The grazing sheep will control weeds, eat cover crop in the alleys to minimize mowing, and eliminate the need for cultivating. The sheep will prune the hop plants by stripping off the lower 2-3 feet of leaves from each bine. This will improve air flow and reduce the risk of downy mildew and powdery mildew, which can heavily damage the entire hop yard if unmanaged. Stripping of the bines also means removing leaves where pests could reside.

    Economic benefits 

    Total yield will be measured and compared to the results from year 1. In Year 1, nothing was done to control pests, downy mildew, or powdery mildew. Therefore, Year 1 harvest results serve as our control. Year 1 (2015) produced 1 pound of dried Centennial hops. This was not enough crop to sell. The total weight of dried hops from Year 2 and Year 3 will be compared to Year 1. This will show improved yield, as a result of effective pest and disease control and natural fertilization. Samples of the crop will be sent to a test lab after each harvest to determine levels of alpha and beta acids. These acids will determine the marketability and price of the crop.

    Using livestock to fertilize the soil and control weeds will reduce labor costs for weeding and mowing. During Year 1, two people spent 8 hours per week weeding and 2 hours per week mowing around one row of hops. Outreach efforts will give more exposure to the newly growing hops industry in Iowa, increasing marketability for small hops growers.

    This is a unique project, especially in a state where agriculture is dominated by corn and soybeans as crops. The conversations this project has initiated have been priceless. Seeing results will help other farmers gain confidence to employ practices that are environmentally friendly. I hope that the results of this project will help to ease the process of gaining organic certification for hops farmers in future years. I want other farmers and hops growers to join in my excitement for sustainability.

    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.