Fluorescence Indices for the Proximal Sensing of Powdery Mildew, Nitrogen Supply and Water Deficit in Sugar Beet Leaves

Agriculture

Georg Leufen¹  Georg Noga² 

[1] Department of Horticultural Sciences, Institute of Crop Science and Resource Conservation, University of Bonn, Auf dem Huegel 6, Bonn D-53121, Germany;

关键词: blue-green fluorescence;    chlorophyll fluorescence;    abiotic stresses;    biotic stresses;    precision agriculture;   

DOI  :  10.3390/agriculture4020058

来源: mdpi

【 摘 要 】

Using potted sugar beet plants we aimed to investigate the suitability of four fluorescence indices to detect and differentiate the impact of nitrogen supply, water deficit and powdery mildew in two sugar beet cultivars (Beta vulgaris L.). Plants were grown inside a polytunnel under two nitrogen levels combined with water deficit or full irrigation. Changes in plant physiology were recorded at two physiological stages with a multiparametric handheld fluorescence sensor and a fluorescence imaging system. The analysis of chlorophyll content and osmotic potential served as reference. Based on our results, the fluorescence indices “Nitrogen Balance Index” and “Simple Fluorescence Ratio” responded quite sensitively to drought stress and mildew infection. Moreover, the blue-to-far-red fluorescence ratio revealed significant stress-induced alterations in the plant physiology. In all, fluorescence indices might be used as single or combined indices for successful stress sensing. However, a robust stress differentiation by using only one fluorescence ratio could not be accomplished.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.