Glyphosate resistant (GR) weeds are a growing concern in crop production agriculture. Glyphosate herbicide has been an effective tool for controlling undesired weeds for over 40 years. We aim to identify key zones with high concentration of GR kochia infestation. Using soil mapping and sensing tools, we will find kochia zones, then monitor those kochia patches over a period of four years, while using a variety of management strategies to control and/or abate kochia.
This study will employ a field scale precision agriculture approach including three, 160-acre fields for four years. Each field will be characterized for salinity, texture, organic matter, pH, nutrients and topography.
Using satellite and drones, including RGB and infra-red images, technicians will capture multiple aerial images throughout the season. They will overlay and integrate the data layers using advanced geographical information systems (GIS) techniques and spatial analysis with the ESRI ARC GIS program. This will produce a composite surface identifying kochia presence to facilitate precise management zones and direct targeted responses to kochia populations.
They will create shapefiles (standard geospatial file format) including polygons of identified kochia and upload them the producers’ on board guidance system for tractors / high clearance sprayers to perform site-specific spray applications when deemed appropriate at various timings including: 1) pre-seed 2) in-crop 3) preharvest 4) postharvest. The priority timing is pre-seed and postharvest as many residual herbicides cannot be applied in crop.
Technicians will conduct visual weed efficacy and tolerance ratings along the edges of spray zones at ten locations 2 weeks and 6 weeks after applications. Yhey will also collect weed biomass samples in treated and untreated locations 6 weeks after treatment.
They will create new kochia maps each season and use reduction in kochia area to evaluate effectiveness. They will track herbicide loads versus a blanket treatment to track the amount and cost of herbicide saved using the site-specific approach.
Project results not expected until 2023
Recommendations will be given when project results have been found and documented.
Herbicide-resistant kochia here to stay