Global Journal of Science Frontier Research, A: Physics and Space Science, Volume 22 Issue 1

Photosynthetic Study of the Effects of Some Weeds in Rice and Vegetable Fields by Spectroscopic and Multimodal Technique in Yamoussoukro (Ivory Coast) Abstract- Optical spectroscopy has been in full expansion for several years for sustainable development, which is a challenge impacting the agricultural sectors. Furthermore, the phytopathological approach by multimodal spectroscopy is an actuality method allowing particular to detect pathogenic diseases in real-time to monitor their development early and consider preventing their spread. The aim of this research is the study of effects caused by weeds according to the phenomenon of photosynthesis influencing the yield of fields of rice and vegetable crops. The multispectral transmission, reflection, and scattering microscope has been used for image acquisition in the ultra-violet to the near-infrared band. Through the microscopic images obtained, the average intensities of the pixels of an area of the image have been evaluated to reconstruct their corresponding spectrum to proceed with a study of their wavelength-by-wavelength optical property. The results obtained by the adopted multimodal technique highlighted the influence of weeds on rice and vegetable plants in the ultraviolet, visible, and near- infrared range in Yamoussoukro in Côte d'Ivoire; also estimating their chlorophyll level at specifique wavelengths. The development of spectroscopic and multimodal analysis methods has mainly contributed to the diagnosis of certain weeds, which are; among others, Boerhaviadiffusa , Echinochloastagnina , Mimosa pigra L. , Euphorbia heterophylla , Perotisindica , Lepto-chloacarulescens , Imperata cylindrical , and Cassia Mimosoideae . Keywords: photosynthesis, weeds, spectroscopic and multimodal analysis, yamoussoukroivory coast. I. I ntroduction n the Ivorian food security policy, agriculture is a challenge in sight to respond to the needs of interior consumption [1]. In recent years, studies of pest and agronomic control methods against weeds have focused on the Ivory Coast between 1968 and 1980 [2]. As a result, weeds have been poorly controlled due to their abundance and resistance in crop fields despite the efforts of other researchers [3, 4, 5]. These constitute a threat on the most rice and vegetable crops. The preventive measures adopted by microbiologists and agronomists require other complementary studies based on optical spectroscopy to eradicate these devastators. Thereby, the establishment of research to improve weed detection tools are needed to develop new control methods. Moreover, to achieve the objectives of sustainable development to improve the yield of the crop production in Africa, particularly in developing countries, optical spectroscopy is considered one of the most promising recent techniques; to effectively prevent and control weeds and other various pathogenic diseases that may slow down the harvest of farmers' fields. Optical spectroscopy, already in use in some African countries for several years, has been the object of medical diagnosis through agriculture [6]. However, the application of optical spectroscopy on weeds rests a multidisciplinary study undeveloped by scientific researchers in Ivory Coast and elsewhere. Thus, to limit the impact of weeds on agricultural production, effective collaboration between local and external researchers has been necessary to carry out this scientific work. It is within this framework; the present research project has been carried out by the Institute of Applied Sciences (ISA) of Bamako-Mali, the Faculty of Sciences and Techniques (FST) under cover of the University of Technical Sciences and Bamako Technologies (USTTB) and the National Polytechnic Institute Félix Houphouët Boigny (INP-HB) Yamous- soukro/Ivory Coast; to achieve the desired objective. The technique developed has been used to carry out a photosynthetic study of the optical properties of certain weeds in transmission, reflection, and diffusion mode and their micro-spectroscopic spectra from measurements by multispectral microscopy in any culture medium tropical all over Africa. The goal is to show the innovation of our technique to characterize the different weeds in the fields of rice crops and those of I 1 Year 2022 1 © 2022 Global Journals Global Journal of Science Frontier Research Volume XXII Issue ersion I VI ( A ) Author α : Laboratoire d’optique, de Spectroscopie et des Sciences de l’atmosphère, Institut des Sciences Appliquées, ISA-USTTB, Mali. e-mail: mamasangare101186@gmail.com Author σ ρ : Laboratoire d’optique, de Spectroscopie et des Sciences de l’atmosphère, Faculté des Sciences et Techniques FST-USTTB-Mali Author Ѡ : Laboratoire d’Instrumentation Image et Spectroscopie, Institut National Polytechnique Felix Houphouët-Boigny Yamoussoukro, Cote d’Ivoire. Mama SANGARE α , K. BERTHE σ , I. TRAORE ρ & O. K. BAGUI Ѡ