HYPERSPECTRAL TECHNOLOGIES FOR ASSESSING SEED GERMINATION AND HERBICIDE RESPONSE IN AMARANTHUS PALMERI
Matzrafi, M.1, Nansen, C.2, Herrmann, I.3 and Eizenberg, H.4
1Department of Plant Sciences, 2Department of Entomology and Nematology, University of California Davis, Davis, California, USA 3Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, Madison, Wisconsin, USA
4Department of Plant Pathology and Weed Research, Agricultural Research Organization, Newe Ya’ar Research Center, Israel
Contact: Amor Matzrafi, email@example.com
Weeds are the most important biotic stressor of cropping systems, decreasing productivity by more than 34% worldwide. Treatments with herbicides are by far the most cost-effective means of controlling weeds. The misuse of herbicides has created high selection pressure driving the evolution of herbicide resistance in various weed species. Amaranthus palmeri has developed resistance to most of the herbicides targeted for its control. Combined with characters such as high seed fecundity and germination in a wide range of temperatures, A. palmeri can be ranked as one of the most noxious weeds in the world. The ability to estimate seed viability and herbicide susceptibility is a key factor in the development of long-term weed management strategies. We developed a toolbox based on hyperspectral technologies and data analyses aimed to predict A. palmeri seed germination and response to the herbicide trifloxysulfuron-methyl. Using hyperspectral imaging, we accurately distinguished between germinating and non-germinating seeds. Sensitive and resistant plants were identified with high degrees of accuracy from leaf contact hyperspectral reflectance profiles acquired prior to herbicide application. High correlation between leaf physiological parameters (photosynthetic rate, stomatal conductence and photosystem II efficiency) and herbicide response (sensitivity/resistance) was also found. Our work demonstrates that hyperspectral reflectance analyses can provide reliable information about seed germination and levels of plant susceptibility in A. palmeri. The use of reflectance-based analyses has enormous potential in preventing ineffective herbicide applications. It also has potential for use in mapping tempo-spatial population dynamics in agro-ecological landscapes.