Article
Testing the Suitability of Automated Machine Learning for
Weeds Identification
Borja Espejo-Garcia *, Ioannis Malounas, Eleanna Vali and Spyros Fountas
Citation: Espejo-Garcia, B.;
Malounas, I.; Vali, E.; Fountas, S.
Testing the Suitability of Automated
Machine Learning for Weeds
Identification. AI 2021, 2, 34–47.
https://doi.org/10.3390/ai2010004
Academic Editor: Amir Mosavi
Received: 28 December 2020
Accepted: 3 February 2021
Published: 9 February 2021
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4.0/).
Agricultural University of Athens, 11855 Athens, Greece; gmalounas@aua.gr (I.M.);
eleannaval1996@gmail.com (E.V.); sfountas@aua.gr (S.F.)
* Correspondence: borjaeg@aua.gr
Abstract: In the past years, several machine-learning-based techniques have arisen for providing
effective crop protection. For instance, deep neural networks have been used to identify different
types of weeds under different real-world conditions. However, these techniques usually require
extensive involvement of experts working iteratively in the development of the most suitable machine
learning system. To support this task and save resources, a new technique called Automated Machine
Learning has started being studied. In this work, a complete open-source Automated Machine
Learning system was evaluated with two different datasets, (i) The Early Crop Weeds dataset and
(ii) the Plant Seedlings dataset, covering the weeds identification problem. Different configurations,
such as the use of plant segmentation, the use of classifier ensembles instead of Softmax and training
with noisy data, have been compared. The results showed promising performances of 93.8% and
90.74% F
1
score depending on the dataset used. These performances were aligned with other related
works in AutoML, but they are far from machine-learning-based systems manually fine-tuned by
human experts. From these results, it can be concluded that finding a balance between manual expert
work and Automated Machine Learning will be an interesting path to work in order to increase the
efficiency in plant protection.
Keywords: automated machine learning; AutoML; weeds identification; deep learning;
precision agriculture
1. Introduction
Nowadays, the damage caused by weeds accounts for important global yield losses
and is expected to increase in the coming years [1]. Although traditionally pesticides were
homogeneously applied to solve this problem, there is a tendency in the EU policy to
reduce the use of plant protection products since they can cause ground environmental
pollution, chemical residues on the crops, and future drug resistance [2]. More specifically,
the EU has set a target to reduce pesticide use by 50% in the next 10 years [3]. Currently,
for applying less dosage of chemical herbicides to weed targets, automatic weed control
arises as a possible solution [4–6].
Recent advances in image classification techniques provide an opportunity for the
improvement of automatic weed control. Despite the delay in the introduction of such
techniques to the agricultural domain, the pace that such technologies are being adopted
is extremely fast. The use of machine-learning-based image analysis presents a relatively
quick, non-invasive, and non-destructive way of controlling weeds spread. In agriculture,
deep learning models have been used in the detection of plant diseases and weeds iden-
tification [7–10]. Convolution Neural Networks (CNNs) are currently the most popular
technique in the agricultural domain since, theoretically, they can mitigate some challenges
such as inter-class similarities within a plant family and large intra-class variations in
background, occlusion, pose, color, and illumination. Besides their good classification
performances, some of these works presented deep neural networks whose inference times
are suitable for real-time agricultural weed control [11].
AI 2021, 2, 34–47. https://doi.org/10.3390/ai2010004 https://www.mdpi.com/journal/ai