Evaluation of convolutional neural networks for herbicide susceptibility-based weed detection in turf

• Published in: Frontiers in plant science Vol. 14; p. 1096802
• Main Authors: Jin, Xiaojun, Liu, Teng, McCullough, Patrick E, Chen, Yong, Yu, Jialin
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 01.02.2023
• Subjects: convolutional neural networks; deep learning; herbicide susceptibility; Plant Science; precision herbicide application; weed detection; deep learning; precision herbicide application; convolutional neural networks; herbicide susceptibility; weed detection
• ISSN: 1664-462X; 1664-462X
• DOI: 10.3389/fpls.2023.1096802

Deep learning methods for weed detection typically focus on distinguishing weed species, but a variety of weed species with comparable plant morphological characteristics may be found in turfgrass. Thus, it is difficult for deep learning models to detect and distinguish every weed species with high accuracy. Training convolutional neural networks for detecting weeds susceptible to herbicides can offer a new strategy for implementing site-specific weed detection in turf. DenseNet, EfficientNet-v2, and ResNet showed high F scores (≥0.986) and MCC values (≥0.984) to detect and distinguish the sub-images containing dollarweed, goosegrass, old world diamond-flower, purple nutsedge, or Virginia buttonweed growing in bermudagrass turf. However, they failed to reliably detect crabgrass and tropical signalgrass due to the similarity in plant morphology. When training the convolutional neural networks for detecting and distinguishing the sub-images containing weeds susceptible to ACCase-inhibitors, weeds susceptible to ALS-inhibitors, or weeds susceptible to synthetic auxin herbicides, all neural networks evaluated in this study achieved excellent F scores (≥0.995) and MCC values (≥0.994) in the validation and testing datasets. ResNet demonstrated the fastest inference rate and outperformed the other convolutional neural networks on detection efficiency, while the slow inference of EfficientNet-v2 may limit its potential applications. Grouping different weed species growing in turf according to their susceptibility to herbicides and detecting and distinguishing weeds by herbicide categories enables the implementation of herbicide susceptibility-based precision herbicide application. We conclude that the proposed method is an effective strategy for site-specific weed detection in turf, which can be employed in a smart sprayer to achieve precision herbicide spraying.