Application of deep learning to detect Lamb's quarters ( Chenopodium album L.) in potato fields of Atlantic Canada

Excessive use of herbicides for weed control increases the cost of crop production and can lead to environmental degradation. An intelligent spraying system can apply agrochemicals on an as-needed basis by detecting and selectively targeting the weeds. The objective of this research was to investigate the feasibility of using deep convolutional neural networks (DCNNs) for detecting lamb's quarters (Chenopodium album) in potato fields. Five potato fields were selected in Prince Edward Island (PEI) and New Brunswick (NB), Canada to collect images of spatially and temporally varied potato plants and lamb's quarters. The image database included pictures, taken under varying growth stages of potato, outdoor light (clear, cloudy, and partly cloudy), and shadowy conditions. The images were trained for DCNN models, namely GoogLe Net, VGG-16, and Efficient Net to classify lamb's quarters and potato plants. Performance of two frameworks, namely Tensor Flow and PyTorch, were compared in training, testing, and during inferring the DCNNs. Results showed excellent performance of DCNNs in lamb's quarters and potato plant classification (accuracy > 90%). However, the Efficient Net with PyTorch framework showed a maximum accuracy of (0.92-0.97) for every growth stage of the plants. Inference times of DCNNs were recorded using three graphics processing units (GPUs), namely Nvidia GeForce 930MX, Nvidia GeForce GTX1080 Ti, and Nvidia GeForce GTX1050. All the DCNNs performed better with PyTorch than Tensor Flow frameworks. It was concluded that the trained models can be used in automation of the spraying systems for the site-specific application of agrochemicals for weed control in potato fields. Such precision agriculture technologies will ensure economically viable and environmentally safe potato cultivation.

Automated summary

The study demonstrated the efficacy of using deep convolutional neural networks (DCNNs) for detecting lamb's quarters in potato fields, with Efficient Net coupled with the PyTorch framework achieving the highest accuracy at every growth stage. The trained models showed great potential for automation of spraying systems in potato fields for precise and environmentally safe weed control.