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

Figure 5: Average spectra of samples collected in scattering (1: Boerhaviadiffusa ; 2: EchinochloaStagnina ; 3: Mimosapigra L. ; 4: Euphorbia heterophylla ; 5: Perotisindica, 6: Leptochloacarulescens, 7: Imperata cylindrical and 8: Cassia Mimosoideae ). In reflection and diffusion, it is also to notice that these same weed species selected in Yamoussoukro reflect and scatter more ultraviolet (375 nm), visible (400 nm-700 nm) radiation than infrared (Figure 4 and 5).On the other hand, the amount of reflected light depends on what has been absorbed by the weeds.The green coloration of the leaf is a function of the degree of absorption of red light to provide the reaction of photosynthesis, at the same time, near-infrared radiation (700nm-940nm) have fully reflected or transmitted [10, 11, 12]. In this case, the spectral study of these weeds shows that they absorb the maximum of chlorophylls (a and b) to capture ultraviolet and visible light.Generally, photosynthesis does not realize in the absence of light radiation. Thus, their chlorophyll level is sufficient to receive and convert the sun's energy into certain nutrients for healthy rice growth; because some of these defense mechanisms can help save water. That is why some species of weeds stay alive to a new culture.Thus, for anwell harvest, spectroscopic information from the multimodal analysis of these weeds isimportant for growers and essential to properly monitor their behavior in crop fields. IV. C onclusion This research project has been realized in collaboration with other researchers, members of the Plant Pathology, and Biology Laboratory at INP-HB and the Image and Spectroscopy Instrumentation Laboratory at INP-HB. It has been proved in this study that the reaction of weeds depends on their optical properties and the growing environment.Optical spectral analysis provides powerful insight into the biochemical content of weed samples in a wide variety of applications. Thanks to spectroscopic techniques; the effects caused by weeds influencing the yield of rice and other vegetable crops have been studied, thus estimating their chlorophyll levels through their spectral variation in terms of transmitted, reflected and scattered light intensities.The results obtained show the potential of the proposed technique; to further facilitating the struggles of agronomists, and the biochemical analyzes in laboratories for the diagnosis of weeds in crop fields to improve agricultural production. An added value, the scientific contribution of this research project is a complementary study on weeds in Côte d'Ivoire and elsewhere using spectroscopic and multimodal techniques, this subject is not sufficiently developed in Africa. A cknowledgments A sincere thank you is addressed to the Ministry of Higher Education and Scientific Research of Mali and the Rectorate of the University of Sciences, Techniques and Technologies of Bamako (USTTB) in partnership with the Institute of Applied Sciences and the Institute National Polytechnique Félix Houphouët-Boigny (INP-HB) of Yamoussoukro / Ivory Coast, to fully fund this research project. In addition, the Image and Spectroscopy Instrumentation Laboratory and the Plant Pathology and Biology Laboratory of the INP-HB of Yamoussoukro, Ivory Coast are respectively thanked for the good practical realization of this research project. R eferences R éférences R eferencias 1. SYLLA M., Traoré K., Soro D. et Yodé T.E.G . Evaluation des pratiques de gestion des adventices en riziculture irriguée dans la localité de Daloa, centre-ouest de la côte d’ivoire ; Agronomie Africaine, 2017, 29 (1), P: 49 – 64. 2. Merlier Henri. La lutte contre les mauvaises herbes en riziculture pluviale en Côte d'Ivoire. Agronomie Tropicale , (1982), 37 (4), p. 408-410. ISSN 0151- 1238. 3. Merlier H. Végétation adventice des rizières pluviales de Côte d’Ivoire. Communication présentée au deuxième symposium sur le désherbage des cultures tropicales COLUMA (Comité français de lutte contre les mauvaises herbes). Montpellier 5-6 septembre 1974,127-140. 4. Touré A. Gestion agronomique et dynamique des mauvaises herbes dans les systèmes de riz de bas fond en Afrique de l’Ouest. Thèse en Sciences Agronomiques, Université d’Abomey-Calavi, Bénin, 2014, 180 p. 5. Tehia K.E., Marnotte Pascal. Nuisibilité des mauvaises herbes en riziculture pluviale en Côte d'Ivoire. In : Dix-huitième conférence du COLUMA. Journées internationales sur la lutte contre les mauvaises herbes, 2001, Toulouse, France = Photosynthetic Study of the Effects of Some Weeds in Rice and Vegetable Fields by Spectroscopic and Multimodal Technique in Yamoussoukro (Ivory Coast) © 2022 Global Journals 1 Year 2022 4 Global Journal of Science Frontier Research Volume XXII Issue ersion I VI ( A )