Vineyard floor management relies on herbicides, especially glyphosate. This practice,
once deemed sustainable and safe, is now jeopardized by glyphosate-resistant weeds and has
come under public scrutiny. Mechanical under-vine cultivators are an option available to grape
growers; many types of equipment are commercially available. However, its adoption lags
compared to herbicides. Under-vine cultivators performance, costs and applications has not been
well-researched. Limited information on reliable providers further hinders adoption of undervine
cultivators. This project proposes 1) to conduct on-farm trials to evaluate different undervine
cultivators types alone or in combinations as compared to herbicide application; 2) With
grower-collaborator participation, we will compare the economics of under-vine cultivation to
herbicide application and record operational information to estimate reliability, operation
capacity, and scheduling of cultivation operation during the growing season; 3)we propose to
compile a list of all equipment commercially available and a list of vendors located in the Western
Region, and to document growers’ perceptions and experiences with under-vine cultivators. This
will allow us to generate specific information about operational costs, performance, the window
of operation, applications, and limitations.
1) Evaluate the weed control performance of three under-vine cultivators (hoe blade,
rotary tiller, and rotary brush) used alone or in combination. Monitor soil structure
using field penetrometer and soil-water content using a portable soil moisture sensor for
development of undesirable trends.
2) Compare under-vine cultivation equipment to herbicide application and record
operational information to estimate reliability, operation capacity, and scheduling of
cultivation operation during the growing season. Grower-collaborators will be active
engaged in this objective, and their input will become the basis for the emphases of
outreach events and materials.
3) Compile a list of cultivators available in the market with estimate costs, operational
capacity, tractor requirement, applications and limitations and develop extension
materials and presentation to promote adoption.
Field experiments will be conducted in commercial vineyards in Oregon located in the Willamette Valley and in the Umpqua Valley. The weed control treatments are:
- hoeing blade,
- rotary tiller,
- brush-weeder plus hoeing blade,
- brush-weeder plus rotary tiller,
- hoeing blade plus rotary tiller,
- brush-weed plus hoeing blade plus rotary tiller,
- herbicide glyphosate,
- untreated control.
Treatments will be performed by an under-vine cultivator manufactured by ID-David. This equipment can be operated with all three cultivators in a single pass, making it a more cost-effective option for growers The experimental design will be a randomized block design with four replicates, which will allow the evaluation of each cultivator individually or in all combinations.
Assessments will be performed 15 and 30 days after each treatment. Weed control will be scored visually using the scale 0% for no control to 100% complete weed control. Additionally, weed growth will be monitored non-destructively using digital image analysis. Weed density and biomass will be estimated at the end of the experimental season. A comparative cost analysis for each treatment will be made including time to accomplish each treatment.
The soil compaction will be monitored using a soil penetrometer at a depth of 15 and 36 inches once per year when soil is at field capacity in late winter-early spring. Ten sites per plot will be sampled.
Soil moisture content: Soil water content will be monitored using a portable moisture probe (Field Scout TDR Soil Moisture or equivalent). Ten measurements per plot will be performed before cultivation. Soil moisture will be monitored during the season as well.
The cost analysis of the cultivator or herbicide operation will be calculated on a per acre basis by recording cost of equipment, machine labor, fuel, lubrication, repairs, and materials use herbicide, sprayer using the formulas proposed by the American Society of Agricultural and Biological Engineers. Collaborating growers working with the cultivator will record: operation speed (mph), operation efficiency (hours/acre), working days (days for which field operation is possible – precipitation, inadequate soil moisture, equipment reliability (down days due to maintenance), field slope, soil type, planting density. This information will allow growers to estimate equipment compatibility with their fields, equipment requirements, and scheduling of activities. These factors will be part of the basis of management practice recommendations. Cultivators that do not disturb soil may have a more extensive window of operation.
To address the lack of information related to under-vine cultivators, we have compiled a draft document listing all equipment commercially available and vendors located in the Western Region. Only equipment with US-based technical support will be included in the list. This list will be available online and will be disseminated during extension meetings.
Educational & Outreach Activities
Cultivation timing relative to soil moisture content
Soil disturbance, disaggregation, compaction