Athletic Field Paint Color Differentially Alters Light Spectral Quality and Bermudagrass Photosynthesis

Abstract

ABSTRACTPainting of athletic fields is widespread throughout the world and can often cause declines in turfgrass health. Visible light and photosynthesis share the same wavelengths (400–700 nm), and it was hypothesized that alterations in visible light to produce specific colors would lead to reductions in photosynthetically active radiation (PAR) and total canopy photosynthesis (TCP). Lab experiments using a spectroradiometer and LICOR 1800‐12 integrating sphere examined the impacts of 10 colors of athletic field paint on PAR as well as wavelengths within PAR. These colors were then applied weekly for 5 wk to ‘Tifway’ bermudagrass [Cynodon dactylon (L.) Pers. × Cynodon transvaalensis Burtt Davy], and TCP was measured using a gas exchange system 24 h after each application. Spectroradiometry analyses revealed the significant effects of paint color (P ≤ 0.001) on reflection, transmission, and absorption of PAR. Lighter colors including white, yellow, orange, and red reflected 47 to 92% of PAR while darker colors including green, black, and dark blue absorbed 87 to 95% of PAR. Accompanying gas exchange measurements revealed that TCP was most negatively correlated with absorption of PAR (r = −0.959, P ≤ 0.001) and that darker colors negatively impact TCP more than lighter colors. The results clearly indicate that damage to turfgrasses with long‐term painting will be difficult to avoid, and this is particularly true with darker colors of paint.