International Journal of Academic and Applied Research (IJAAR)   Year: 2021 | Volume: 5 | Issue: 6 | Page No.: 113-119 Generate Traveling Acoustic waves on the Surface of Sun and Shadow Plant by Photoacoustic Spectroscopy Salma A. H .Ali ,Mubrarak Dirar Abd-Alla, , Abdalskhi .S.M.Hamed &Abdalgadir.Alfa.Abdalgadir Abstract: In this study, used Photoacoustic spectroscopy (PAS) generate traveling acoustic waves on the surface of plant that growth in Sun and Shadow (Bougainvillea spp 1l in shadow, Bougainvillea spp 1 in sun, Citrus Sanseis in sun, Citrus Sanseis in shadow, Canna Indicia in sun, Canna Indicia in shadow, Ixora Coccinnia in sun, Ixora Coccinnia in shadow, Bougainvillea Spp2 in sun, Bougainvillea Spp2 in sun, Citrus Paradisi in shadow and Citrus Paradisi in sun). In this study applied Diodes Laser 450 nm power (4.4) mW . The periodic variation in the strain leads to a periodic variation in the refractive index owing to the photo elastic effect .For all samples generate traveling acoustic waves on the surface of a plant at frequency range (0.014x1014 and 0.85x1014) Hz.