Beneficial Insects in the Vineyard

Progress report for RGR20-001

Project Type: Research to Grass Roots
Funds awarded in 2020: $43,515.00
Projected End Date: 12/31/2022
Host Institution Award ID: G113-21-W7906
Grant Recipients: Walla Walla County Conservation District; Walla Walla Community College Institute of Enology and and Viticulture
Region: Western
State: Washington
Principal Investigator:
lynda oosterhuis
Walla Walla County Conservation District
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Project Information

Abstract:

Valuable information was gained from WSARE project SW10-052, Native Habitat Restoration, IPM and Beneficial Insect Conservation, providing the groundwork for viticulturists in Washington's Columbia Valley to implement conservation biological control into their vineyard management strategies.  The research  concluded that several of the native shrub-steppe species provide quality habitat for beneficial insects that can control the most problematic vineyard pests.  Vineyards and wineries have a direct relationship with the end consumer.  More and more these consumers are demanding that agriculture producers are good stewards of the land and are willing to pay more for these products. This can lead growers to interest in implementing more sustainable practices on their land. There is a need to sort through the research and narrow down the best practices for the Walla Walla Valley.  Having clear guidelines, designs, plant list and a step by step guide could provide the missing link to the implementation of habitat plantings in area vineyards.  Planting native species adjacent to and in vineyards not only provides habitat for insects that prey on vineyard pests, it also provides habitat for pollinators, game and songbirds that have lost habitat from the increase in acres of land cultivated for grape production. 

The Walla Walla Community College's Institute of Enology and Viticulture is a key member of the Walla Walla Valley wine making community.  A partnership between the college and the Walla Walla County Conservation District is a way to reach area viticulturists and soon to be vineyard owners and managers graduating from the College's wine program.  Many of the students have never been involved in agriculture or in making land use decisions and may not be aware of the impacts these decisions can have. Implementing habitat plantings in and around vineyards can be an approachable first step into being more in tune with the ecological processes on the land.

Project Objectives:

Increasing awareness of the benefits of using  conservation biological controls in the vineyards around the Walla Walla Valley is the main objective of this project. A secondary objective is to promote agricultural biodiversity in vineyards to develop a stronger, more adaptable ecosystem in the face of a changing climate.  The dry, hot climate of Walla Walla makes it an ideal location for implementing conservation biological controls.  The research and empirical evidence exists to support the value of increasing vegetation diversity in vineyards and surround landscapes, allowing non crop species to grow in and around the grape blocks. "One of the known problems with monoculture is the diversity, abundance and activity of natural enemies of pests is drastically decreased due to the removal of vegetation that provides critical food resources and over wintering sites necessary for the longevity, reproduction and survival of many predators and parasites" ( Alteri, et, al, 2010)

  The grant funds will be used to connect viticulture students, area vineyard managers and agricultural professionals with the best information needed to  implement these practices. Collaboration between the Enology &Viticulture program, the Walla Walla County Conservation District and the area  grape growers committed to sustainable farming practices provides a direct connection of those currently making land use decision,those that will soon be making these decisions the agency that can provide the resources needed to implement these practices.  Roughly 30 students graduate from the E&V program every year.  Many of those students will go on to own or manage vineyards in Walla Walla. These new land managers may be open to preserving existing habitat or incorporating new habitat into their operations if  given a clear path to adopting biological controls.

Altieri, M., Nichols, C., Wilson, H., Miles, A., 2010. Habitat Management in Vineyards; A growers manual for enhancing natural enemies of pests. Laboratory of Agroecology, Berkeley, CA. p.4

Introduction:

The previously funded WSARE grant. Native Habitat Restoration, Sustainable IPM and Beneficial Insect Conservation,  was an in- depth study of the potential value of conserving or restoring the shrub-steppe of eastern Washington " improving and sustaining biologically-based pest management, while providing essential resources for threatened pollinators like butterflies and bees" (James, 2014).  The study was successful at showing the value of the areas natives species and  narrowing down the potential plants from 103 to 10 that are most attractive to beneficial insects. These native plants had abundant populations of generalists and specialist predators.  This gives strength to the argument that vineyards around the Walla Walla Valley can reduce reliance on pesticides but  to do this there needs to be diverse food resources and overwintering habitat for the predators that will keep pest pressure below the economically tolerable threshold.   The study also found that these same native species provided habitat for many of the threatened pollinators and butterflies native to this region. 

There are  only a handful of vineyards in the Walla Walla Valley that incorporate habitat plantings into their vineyards but this study shows the potential for this to become the norm. The dry, warm, windy climate of eastern Washington, keeps pests populations down and are less likely to be problematic as in the western side of the state.  This makes using biological controls, a realistic prospect. What is lacking is guidelines and a step to step approach to implement these practices in the different sub AVA's of Walla Walla Valley.

"In general, on going research conducted nationwide demonstrates a strong link between conservation of natural habitat and reduced pest problems on farms" (Morandin et al, 2012.)  The knowledge and experience with biological controls is plentiful, it is a matter of connecting those findings to the growers interested in restoring agricultural biodiversity on their farms.  Grape growing is a risky business venture, and it is only the few that are willing to invest manpower and resources in practices that do not yield tangible financial gain.  Much of the native sagebrush-desert steppe habitat has been removed from the expansion of the wine grape growing business in and around eastern Washington. Reducing complex ecosystems down to simplified monocultures comes at the expense of many species of that have co-evolved to flourish on this landscape.  The vineyards that already have native habitat plantings can provide first hand experience as to what works and what doesn't.  California vineyards have a longer history in grape growing and there are many examples of vineyards that have adopted "farmscaping" as part of their vineyard management plans.  This resource along with the previous WSARE grant can be translated into a guide that speaks directly to conditions in the Walla Walla Valley.

James, D.G., 2014.  Native Habitat Restoration, Sustainable IPM and Beneficial Insect Conservation. Western SARE project SW10-052, Final Report p.24.

Morandin, L., R.F. Long, C. Pease, and Kremen. 2011. Hedgerows enhance beneficial insects on farms in California's central valley. Calif. Agric. 65:197-201.

 

Timeline:

The second year of the “Beneficial Insects in the Vineyard” project started out with the installation of two 100’ hedgerows in Walla Walla Community College’s Myles Anderson Vineyard.  Over 100 trees, shrubs and forbs were planted with the help of students from the Enology and Viticulture program.  The initial work included site prep, planting, mulching, and setting up drip irrigation.  During the summer months, we regularly weeded, irrigated, monitored new plantings and rehabbed an older habitat planting.  It was a challenging year for transplants, but a majority of plants survived the drought, extreme temperatures and deer browse. The recommended planting list will focus on species that do not require irrigation or much maintenance beyond the first years even in extreme conditions. Criteria for success include plant survival, length of bloom time, availability at regional  nurseries, and attractiveness in a landscape and to beneficial insects.  Each hedgerow was mulched with scrap card board as it was being planted. This is an easy material to obtain and work with.  One hedgerow was mulched directly around each plant, and in the other, the cardboard mulch covered  the entire 100’ planting area. The difference was dramatic. The hedgerow with full mulching had less weed pressure and plants tolerated the extreme temperatures better. 

 Insect monitoring was conducted in both participating  vineyards between April and October.  In each vineyard, 4 sticky traps were set up at 10 meter intervals from habitat areas. Traps were checked and tallied every other week.  Insects were counted and classified as pests or beneficial species. Efforts were made to identify each insect down to Order or Family if regularly occurring in the vineyard.  Foliage scouting and leaf sampling were conducted in each vineyard twice during the growing season. This clarified which plant species are favored by beneficial insects and or pests at different times of the year.  Some general trends in beneficial and pest populations were observed throughout the growing season, though it is hard to correlate a direct relationship to habitat plantings and species populations. A higher concentration of beneficial insects in and around the hedgerow suggests that these plantings are providing necessary habitat and food resources for desired insects. Though not initially planned,  a third season of insect monitoring will be conducted if time and funds allow.  Populations of pest species, mainly Grape leafhoppers and Grape thrips, fluctuated throughout the growing season but never reached a level of concern in ether vineyard.

The planned winter 2020 seeding at Woodward Canyon Vineyard was delayed due to weather. The lack of moisture from February through September would have resulted in a failed seeding.  Sheep fescue, a low growing, adaptable, bunch grass, was seeded down the drive rows of a 1 acre block in November of 2021. We will inter-seed forbs in the fall, comparing a seed mix drilled directly into the grass, versus transplanting plugs. The species best suited to this low rainfall site will be Rabbitbrush, Yarrow, Blanket flower and several wild flowering Buckwheat. I will be meeting with the vineyard manager as weather allows to map out the seeding area, go over seeding rates and equipment used. We will monitor the grass growth and weed pressure through the spring and summer.  The in-between row plantings will be considered successful if it keeps the Yellow Starthistle pressure down while providing  habitat and a food source throughout the vine blocks.  Wine grapes in this region are primarily hand pruned and harvested and plantings with- in the vine blocks need to consider the vineyard crews that use these areas regularly.

The on-line guide material is being drafted and edited with the help of a graphic designer.  The guide includes sections on conservation biological controls, project planning, site prep, planting, budget, monitoring, marketing and links to technical and potential funding sources. We are discussing the different online publishing  options. The ideal format will be easy to print out and edit on-line.

Speakers are being confirmed for the workshop in June. The workshop will address  questions and concerns with planting habitat in a vineyard, costs, and the basics of conservation biological controls. Speakers include staff from The Xerces Society, an experienced landscape designer and a local native plant nursery manager.  Regional vineyard owners that have implemented habitat plantings into their vineyards will also be invited to speak or participate in the workshop. Regional NRCS staff will be in attendance to talk about funding options through federal programs focused on pollinators and creating habitat on working lands. The hope is that the workshop will be a combination of formal presentations and less formal conversations among the participants. We will have time to walk through the demonstration garden, conduct  insect scouting and discuss the benefits of supporting bio-diversity in a changing climate. Relationship building and increasing knowledge of the available resources are the goals of the workshop. With the on-going restrictions and concerns with in-person gatherings, we will be meeting 100% outdoors.

Cooperators

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  • Kern Ewing (Educator)
  • Joel Perez - Producer (Educator)
  • Tara Piraneo - Producer
  • Sager Small - Producer
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.