Orchard Floor Management

Orchard floor management covers a number of aspects including weed control, soil health, ground cover selection and management, management of prunings, mulching, water management, rodent control, and soil amendments and nutrient additions. Often an action in one of these areas affects a number of others. For example, mulching might be used to control weeds, but can also conserve water, improve soil condition and tree performance, and enhance biocontrol of codling moth larvae with entomopathogenic nematodes.  Growers are combining recent research findings with novel management and tools to get results from a part of the orchard ecosystem that has been considered less impactful than the above ground tree.

Resources

Presentations

• Orchard Floor Management.  D. Granatstein. Presentation at the Organic Orchard Floor Management workshop, Wenatchee, October 2016.
• Orchard Floor Management.  D. Granatstein. Presentation to the WSU Horticulture 421 class.
• Orchard understory management options: moving from headache to money maker. D. Granatstein.
• Optimizing understory management in Northwest orchards. D. Granatstein et. al.

Manuscripts

• Biointensive Management of the Orchard Understory., D. Granatstein, pdf

Cover Crops

Cover crops can perform many functions in perennial crops such as orchards and vineyards. These include erosion control, improved soil structure, nitrogen fixation, and habitat for beneficial insects. At the same time, species need to be selected carefully to avoid unintended problems with insect pests, rodents, or hosting pathogens or nematodes.

Cover Crop Workshop for Orchards and Vineyards

May 19, 2011 — Quincy, WA Sponsored by USDA NRCS Plant Materials Center and WSU Center for Sustaining Agriculture and Natural Resources.
This event featured a series of presentations on the opportunities for cover crops in perennial fruits along with a visit to several orchard blocks planted with legume cover crops for internal nitrogen and biomass production. See the workshop presentations below:

• Cover crops for orchards. David Granatstein, WSU Wenatchee. General principles for selecting cover crops for orchards, examples from published research, current research on using perennial legumes to supply nitrogen and biomass with mow and blow.
• Cover crops for grape production. Joan Davenport, WSU Prosser. Results from screening species for alley vegetative cover without irrigation, and testing annual legumes in Concord grape vineyards for nitrogen supply.
• Cover crops: inviting natural enemies into your orchards. Betsy Beers, WSU Wenatchee. Using selected flowering plants as cover crops to enhance biological control; previous research findings, testing alyssum for woolly apple aphid control in Washington State.
• Enhancing biocontrol with perimeter plantings. Tom Unruh, USDA-ARS, Wapato, WA. Principles of habitat modification for encouraging biocontrol with plantings in and around orchards.  Experience with leafroller biocontrol and roses; alfalfa and pear psylla.

Presentations

• Assessing effects of an alfalfa cover crop on biological control and tree nutrition in organic pear orchards, D. Horton, T. Unruh, and V. Jones.
• Cover crop resources from the Plant Materials Center.  Pamela Pavek, USDA-NRCS Plant Materials Center, Pullman, WA. History of cover crop work, examples of useful resources, possible collaboration.
• Direct Seeding Legumes into Orchard Alleys for Nitrogen Production.  Poster presented at the 2012 International Organic Fruit Research Symposium, Leavenworth, WA.  Based on field trials in apples.

Web pages

• Cover cropping, CSANR (Center for Sustaining Agriculture & Natural Resources) webpage

WSU Publications

• Granatstein, D., E. Kirby, and  J. Davenport. 2013. Direct-seeding legumes into orchard alleys for nitrogen production. Acta Hort. 1001: 329-334.
• Davenport, J. R., K. E. Bair, and R. G. Stevens. 2011. The Relationship Between Soil Temperature and N Release in Organic and Conventionally Managed Vineyards. Commun. Soil Sci. Plant Anal: In Press.
• TerAvest, D., J.L. Smith, L. Carpenter-Boggs, D. Granatstein, L. Hoagland, and J.P. Reganold. 2011. Soil carbon pools, N supply, and tree performance under several ground cover management systems and compost rates in a young apple orchard. HortScience 46:1687-1694.
• Mullinx, K. and Granatstein, D. 2011. Potential nitrogen contributions from legumes in Pacific Northwest apple orchards. Intl. J. Fruit Sci. 11:74-87.
• TerAvest, D., J.L. Smith, L. Carpenter-Boggs, L.Hoagland, D. Granatstein, and J.P. Reganold. 2010. Influence of orchard floor management and compost application timing on N partitioning in organically managed apple trees. HortScience. 45:637-642.
• Horton, D.A., T. Unruh, V. Jones. 2010. Quantifying biological control of pear psylla in a cover crop system. Final project report.
• Granatstein, D., M. Wiman, E. Kirby, and K. Mullinix. 2010. Sustainability trade-offs in organic orchard floor management. Acta Hort. 873:115-122.
• Granatstein, D. and E. Sanchez. 2009. Research knowledge and needs for orchard floor management in organic tree fruit systems. Intl. J. Fruit Science 9:257-281.
• Wiman, M.R., E.M. Kirby, D.M. Granatstein, and T.P. Sullivan. 2009. Cover crops influence meadow vole presence in organic orchards. HortTech 19:558-562.
• Hoagland, L., Carpenter-Boggs, L., Granatstein, D., Mazzola, M., Smith, J., Peryea, F., and Reganold, J. P. 2008. Orchard floor management effects on nitrogen fertility and soil biological activity in a newly established organic apple orchard. Biol.  Fert. Soils 45:11-18.
• Bair, K. E., J. R. Davenport, and R. G. Stevens. 2008. Release of Available Nitrogen Following Incorporation of a Legume Cover Crop in Concord Grape. HortScience43: 875 – 880.
• Olmstead, M.A. 2006. Cover crops as a floor management strategy for Pacific Northwest vineyards. On-line extension bulletin EB 2010.
• Olmstead,M.A., R.L. Wample, S.L. Greene, and J.M. Tarara. 2001. Evaluation of Potential Cover Crops for Inland Pacific Northwest Vineyards Am. J. Enol. Vit. 54:292-303.

More Resources

• Legume covers in orchard drive alleys final study report. 2016. P. Pavek and D. Granatstein. USDA-NRCS report.
• The potential for cover crops in Washington apple orchards.  2014.  P. Pavek and D. Granatstein. USDA-NRCS report.
• Cover cropping systems for organically farmed vineyards. 2004. Glenn McGourty, UC Cooperative Extension, article.  Advice on selecting and using cover crops in organic winegrape vineyards.
• Cover cropping in vineyards: a grower’s handbook. Ingels. C.A. et al. (eds). Univ. California DANR Publ. 3338. 162 pp.  A comprehensive reference on using cover crops in vineyards under California conditions

Mulching & Tillage

Video

• Reduced tillage on organic farms virtual field day, (youtube video)

Presentations

• Comparing Tillage and Mulching for Organic Orchard Performance, M. Wiman et al. Poster presented at 2008 Washington State Horticulture Association annual meeting, Wenatchee, WA. Based on field trials on organic apples.
• Using Mulches to Improve Efficacy and Persistence of Insect Specific Nematodes for Control of Overwintering Codling Moth, by L.A. Lacey, D. Granatstein, H.L. Headrick, R. Fritts Jr., and S. Arthurs. 2004. A poster summarizing the 2004 results of using entomopathogenic nematodes in conjunction with mulch to enhance mortality of codling moth larvae.
• Sprayable paper mulch for organic row crop production, D. Granatstein et al.
• Improving crop yield and soil quality with mulches and cover crops, E.J. Hogue, 2003
• Mulching systems for weed control, water conservation, and nitrogen management in organic apple orchards, D. Granatstein et al., 2002
• Orchard mulching and cover crop trials, D. Granatstein and G. Hogue, 2001

Reports

Several field trials were conducted evaluating various orchard floor strategies, including tillage, living mulch, and wood chip mulch.  Unpublished reports from these projects are presented below that contain more detailed information than the final publications.

• Understory management progress report 2004. Comparison of tillage, wood chip mulch, and mowing.
• Screening Annual and Perennial Ground Covers as In-Row Living Mulch for Central Washington Orchards, 2004, D. Granatstein, et al. The first report on a new field trial examining potential candidates as living mulches for use in the tree row of orchards.
• Progress Report 2005 Living Mulch. Second year results for original living mulch trial and first year results for subsequent trial in a newly planted orchard.
• Living mulch trial 1 update. 2005 update on living mulch trials.
• Progress Report 2005 Understory.  Living mulch and multiple mulch trials.
• Progress Report 2006 Living Mulch.
• Integrated Multiple Mulch trial progress report, D. Granatstein et al. Discusses the first year results of a new organic apple orchard planting comparing bare ground, tillage, wood chip mulch, living mulches, and Sandwich system for understory management in the tree row. Includes data on tree growth, weeds, cover crop performance, and vole populations.
• Growing nitrogen in the orchard. Year 1, 2008. Year 2, 2009. Year 3, 2010.

Other Reports

• Availability of Mulch Material for orchards in Central Washington,  2002. D. Granatstein, E. Kirby, and L. VanWechel. A general survey on availability and cost of potential mulching materials including mint slugs, hop waste, straw, wood chips, sawdust and paper.
• Orchard Mulching Field Day Report, 2001. D. Granatstein. A summary of the mulching and cover crop trials underway in Wenatchee, WA.
• Vole populations, tree fruit orchard, and living mulches 2006. Literature review by T. Sullivan on living mulches in orchards and the potential to cause a vole problem.

Weed Management

Video

• Weed Control in Orchards, David Granatstein, Jan. 2015 video presentation at the Lake Chelan Hort. Day. An overview of the various methods, both chemical and non-chemical for controlling weeds in orchards.

Manuscripts/ reports

• Productivity, Economics, and Fruit and Soil Quality of Weed Management Systems in Commercial Organic Orchards in Washington State, USA. 2014. D. Granatstein, P. Andrews, A. Groff. Results from a study of 3 different weed control systems in commercial organic orchards, including costs of the methods and their effects on overall orchard economics. Additional details not in the manuscript (e.g. itemized costs for each weed control method; effects on grass vs broadleaf weeds; fruit size; fruit quality) are in the On-line Resources document.
• Effectiveness of weed control strategies for organic orchards in central Washington, 2005. D. Granatstein et al. Year 2 report on a field trial comparing various weed control strategies for organic orchards, including control (mowed weeds), wood chip mulch, a commonly used mechanical cultivator, and a new mechanical cultivator.

Web pages

• Weed Management, CSANR (Center for Sustaining Agriculture & Natural Resources) webpage

2011 UC Extension Organic Tree Fruit Workshop Presentations, Sacramento, CA

• Weed and Nutrient Management in Organic Orchards, D. Granatstein
• Weed Control Options, T. Lanini
• Finding Cost-Effective Weed and Nutrient Management Practices in Organic Pear Orchards, C. Ingels