Dicotyledon Weed Quantification Algorithm for Selective Herbicide Application in Maize Crops

Morten Laursen,Anders Mortensen,Thomas Giselsson,Peter Jensen,Henrik Midtiby,Kjeld Jensen,Rasmus Jørgensen,Martin Christiansen

doi:10.3390/s16111848

Abstract

The stricter legislation within the European Union for the regulation of herbicides that are prone to leaching causes a greater economic burden on the agricultural industry through taxation. Owing to the increased economic burden, research in reducing herbicide usage has been prompted. High-resolution images from digital cameras support the studying of plant characteristics. These images can also be utilized to analyze shape and texture characteristics for weed identification. Instead of detecting weed patches, weed density can be estimated at a sub-patch level, through which even the identification of a single plant is possible. The aim of this study is to adapt the monocot and dicot coverage ratio vision (MoDiCoVi) algorithm to estimate dicotyledon leaf cover, perform grid spraying in real time, and present initial results in terms of potential herbicide savings in maize. The authors designed and executed an automated, large-scale field trial supported by the Armadillo autonomous tool carrier robot. The field trial consisted of 299 maize plots. Half of the plots (parcels) were planned with additional seeded weeds; the other half were planned with naturally occurring weeds. The in-situ evaluation showed that, compared to conventional broadcast spraying, the proposed method can reduce herbicide usage by 65% without measurable loss in biological effect.

Highlights

The general practice of controlling emerged weeds in arable fields consists of the uniform application of a selective herbicide
Images were acquired with a Basler Ace aca2000-50gc RGB camera (Basler AG, Ahrensburg, Germany) equipped with a Bayer patterned color filter in front of a complementary metal–oxide–semiconductor (CMOS) sensor
This section describes the method of exclusion for the remaining plots and the results from the 241 accepted plots

Summary

Introduction

The general practice of controlling emerged weeds in arable fields consists of the uniform application of a selective herbicide. This ensures a competitive advantage for the crop without severely damaging it. In 2010, pesticide residues were found in 44% of the drinking water monitoring points in Denmark, and the accepted limit of 0.1 μg/L was exceeded in 15% of the monitoring points [3] This led to stricter regulation of herbicides prone to leaching and greater cost for the agricultural industry through taxation. These developments have encouraged investment in research on technologies that can reduce the amount of herbicides used in crops without affecting the herbicidal effect

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Results

Discussion

Conclusion