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

Figure 2: Methodological flowchart III. Results And Discussion After the data analysis, figures 3, 4, and 5 are the results obtained for each study mode according to the thirteen wavelengths ranging from ultraviolet to near- infrared. Figure 3: Average spectra of samples collected in transmission (1: Boerhaviadiffusa ; 2: Echinochloa Stagnina ; 3: Mimosapigra L. ; 4: Euphorbia heterophylla ; 5: Perotisindica, 6: Leptochloacarulescens, 7: Imperata cylindrical and 8: Cassia Mimosoideae ). The spectral distribution of the different transmission weed species (Figure 3 above) constitutes those that are likely to generally attack rice crop fields, and market garden plants in Yamoussoukro.They transmit quantitatively less UV and visible light (between 375 nm and 660 nm) in terms of intensities. It is in the visible radiation stage that photosynthesis unfold, carrying away some nutrients necessary for the plant leaves. However, the spectroscopic study in the same bands certifies that the sorted weeds behave similarly to a healthy leaf . Hence, it is often difficult to visually differentiate weeds from certain crop plants (rice fields, for example). In addition, a leaf that transmits less visible light absorbs a sufficient amount of chlorophyll,playing the process of photosynthesis to provide more nutrients to crops. Thus, the effect of these weeds has not to influence on rice crops and vegetable crops; hence they resist better by strengthening these cultures. On the other hand, these same species transmit the maximum infrared wavelength with an insufficient concentration of chlorophyll to not effectively play the phenomenon of photosynthesis. That often causes yellowing and wilting of these weed species by attacking rice leaves and vegetable plants in fields.It is also to consider that their rate of chlorophyll concentration varies from one electromagnetic radiation (UV-Visible) to another (Near-Infrared) to play probably appropriately the phenomenon of photosynthesis using light energy. Among the weeds studied by our transmission multispectral imaging method, Leptochloacarulescence and Perotisindica have practically no influence on vegetable plants because of their high amount of chlorophyll for photosynthesis because they absorb more electromagnetic light ranging from ultraviolet to visible (375 nm to 700 nm) than they transmit in terms of intensities.But, Imperatacylinchical (sample 7) is considered one of the most dangerous weeds among those studied in Yamoussoukro because it transmits the maximum infrared light ranging from 660 nm to 940 nm. Nevertheless, spectroscopic analysis shows that the weeds selected in our study have peaks characteristic of a healthyleaf at 660 nm with variable behavior playing the role of photosynthesis in rice and vegetable fields.Thus, despite the degree of influence of these weeds on the sampled fields, it is likely to have a good harvest depending on the growing environment. Figure 4: Average spectra of samples collected inreflection (1: Boerhaviadiffusa ; 2: EchinochloaStagnina; 3: Mimosapigra L.; 4: Euphorbia heterophylla ; 5: Perotisindica, 6: Leptochloacarulescens, 7: Imperata cylindrical and 8: Cassia Mimosoideae ) Photosynthetic Study of the Effects of Some Weeds in Rice and Vegetable Fields by Spectroscopic and Multimodal Technique in Yamoussoukro (Ivory Coast) 1 Year 2022 3 © 2022 Global Journals Global Journal of Science Frontier Research Volume XXII Issue ersion I VI ( A ) [9] Compared to the weeds EchinochloaStagnina and Euphorbia heterophylla , which influence rice crops, the spectroscopic study suggests that only Euphorbia heterophylla transmits less visible light during photosynthesis in a field of rice cultivation;thus, its presence will not affect on the evolution of rice.