Drought stress impact on the performance of deep convolutional neural networks for weed detection in Bahiagrass

Machine vision-based weed detection relies on features such as plant colour, leaf texture, shape, and patterns. Drought stress in plants can alter leaf colour and morphological features, which may in turn affect the reliability of machine vision-based weed detection. The objective of this research was to evaluate the feasibility of using deep convolutional neural networks for the detection of Florida pusley (Richardia scabra L.) growing in drought stressed and unstressed bahiagrass (Paspalum natatum Flugge). The object detection neural networks you only look once (YOLO)v3, faster region-based convolutional network (Faster R-CNN), and variable filter net (VFNet) failed to effectively detect Florida pusley growing in drought stressed or unstressed bahiagrass, with F1 scores ≤0.54 in the testing dataset. Nevertheless, the use of the image classification neural networks AlexNet, GoogLeNet, and Visual Geometry Group-Network (VGGNet) was highly effective and achieved high (≥0.97) F1 scores and recall values (≥0.98) in detecting images containing Florida pusley growing in drought stressed or unstressed bahiagrass. Overall, these results demonstrated the effectiveness of using an image classification convolutional neural network for detecting Florida pusley in drought stressed or unstressed bahiagrass. These findings illustrate the broad applicability of these neural networks for weed detection.     

基于学习矢量量化神经网络的水稻白穗和正常穗的高光谱识别

水稻病虫害的发生会导致大量白穗的出现,对白穗和正常穗的区分是采取植保措施和灾害评估的基础。通过研究获取了由水稻二化螟和穗瘟造成的白穗和正常穗的室内光谱,选取红边斜率、红边面积、绿峰幅值和绿峰面积等4个高光谱变量作为输入向量,利用学习矢量量化（LVQ）神经网络对水稻白穗和正常穗进行分类。利用测试样本对网络进行测试,结果显示对白穗和正常稻穗的分类精度高达100%。研究表明,基于LVQ神经网络对水稻白穗和正常穗进行辨别的方法是切实可行的,可以补充和替代肉眼观测。