Particle Film Improves the Physiology and Productivity of Sweet Potato without Affecting Tuber's Physicochemical Parameters

In tropical areas, the lower productivity of sweet potato has been related to unfavorable climatic conditions, as heat stress caused by high temperatures limits the optimal genotypic expression of plants. Innovative techniques, such as particle films, have been proposed to reduce productivity loss caused by such conditions. Herein, we examine whether applying calcium oxide particle films could minimize heat stress on sweet potato under field conditions, reflecting higher productivity. For this purpose, sweet potato plants were exposed to four concentrations of calcium oxide particle film (0, 5, 10, and 15% w/v) applied onto leaves and assessed regarding the physiological, physicochemical, and productivity parameters. Overall, in plants treated with calcium oxide particle films, the photosynthetic rate, intercellular CO2 concentration, water use efficiency, and carboxylation efficiency increased compared to untreated plants. Moreover, we observe a reduction in leaf temperature and stomatal conductance of up to 6.8% and 45%, respectively, in sweet potato plants treated with 10% w/v, resulting in higher productivity (34.97 ton ha(-1)) compared to the control (21.55 ton ha(-1)). No effect is noted on tuber physicochemical parameters. In summary, the application of a calcium oxide particle film seems to favor sweet potato crops, alleviating the stress caused by hot climatic conditions in tropical regions.