Task map spraying with VRA, also called prescription map spraying, uses a digital map to set application rates by location. With WEED-IT precision spraying, developed and manufactured by Rometron, you combine AQRATE and DASH with individual nozzle control using PWM.
A prescription map, also known as a task map or application map, is a digital field map containing location-specific application rates. It divides the field into zones or cells, each with its own prescribed rate.
During spraying, the position of the sprayer is matched with the information in the prescription map. The spraying system then automatically adjusts its output according to the prescribed rate for that specific location.
VRA stands for Variable Rate Application. With VRA spraying, the application rate changes automatically while you drive across the field.
VRA can use prescription maps prepared in advance or real-time information from the field (Live VRA). This article focuses on the first approach: the sprayer follows application rates specified in the map before spraying.
The process starts before the sprayer enters the field. A task map is created using available field data. Depending on the application, this information may come from crop observations, previous field operations, sensors, satellite imagery, drones or farm management software. With WEED-IT, the process is as follows:
WEED-IT AQRATE is designed to give farmers and contractors more control over the application rate of individual nozzles.
AQRATE uses Pulse Width Modulation technology to regulate nozzle output while keeping the spray pressure constant. This means application rates can change without relying solely on adjustments to spray pressure or driving speed.
In combination with WEED-IT DASH software, AQRATE can execute prescription maps at a resolution of 25 x 25 cm. This allows the sprayer to follow detailed application instructions across the field.
You need DASH to execute prescription maps with WEED-IT. The ISOBUS terminal cannot execute these maps.
A task map specifies the application rate. PWM translates that instruction into the required nozzle output.
PWM rapidly switches individual nozzles on and off. By varying the proportion of open and closed time, the system controls nozzle output.
With task map spraying, the application is based on information stored in a digital map. The required rate for each location has already been determined before the sprayer reaches that part of the field.
WEED-IT spot spraying uses real-time plant detection. WEED-IT sensors use chlorophyll fluorescence to detect living green material and activate the appropriate nozzle when a target is detected.
In WEED-IT cover spraying, a WEED-IT-equipped sprayer can perform a full-field application using individual nozzle control, PWM, speed compensation and curve compensation.
During a variable rate broadcast application, the application rate follows the prescription map. Instead of applying the same amount everywhere, you apply the rate prescribed for each location.
WEED-IT therefore offers different spray modes, allowing operators to select an application strategy that matches the field conditions and objective.
Crop development, weed pressure and soil characteristics can vary within a field. A prescription map lets you adjust application rates to these differences.
Depending on the map and the application, this can help you:
Precision agriculture uses data to account for variation within fields.
The role of precision agriculture in managing in-field variability is also described by the European Commission Joint Research Centre.
The European Commission Joint Research Centre also identifies variable rate pesticide application as a precision agriculture technology for managing spatial differences in weeds and diseases.
With WEED-IT QUADRO, operators can use multiple spraying modes, including spot spraying, cover spraying, dual spraying and Spot-in-Crop.
The technology can also be integrated with different spraying platforms, including self-propelled sprayers. Existing sprayers can therefore be equipped with precision spraying technology without necessarily replacing the complete spraying platform.
A prescription map is a digital field map specifying the application rate for each location. It is also known as a task map or application map.
VRA stands for Variable Rate Application: an application rate that can change by location. It can be based on prescription maps or real-time information.
Yes. WEED-IT AQRATE and DASH can execute task maps at a detail level of 25 x 25 cm. DASH is required for this application.
Prescription map spraying follows application rates specified in advance. WEED-IT spot spraying uses sensors to detect living plants in real time and activates the appropriate nozzles when a target is detected.
PWM controls individual nozzle output while maintaining the selected spray pressure. It also compensates for changes in driving speed and speed differences between the inside and outside of the boom when turning.
It can when the task map identifies areas that need a lower application rate. Savings depend on the field, the product, prescribed rates and the quality of the field data. There is no fixed saving percentage.
Prescription map spraying with VRA combines field data, WEED-IT AQRATE and DASH. The map specifies how much to apply at each location; PWM controls the output of each nozzle.
Want to know how task map spraying with VRA can work with your sprayer? Talk to a WEED-IT specialist or local distributor and find out which setup fits your operation.
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