ABSTRACT High temperatures may affect the development and yield of the sweet potato crop. Technologies such as particle films can mitigate their effects. This study aimed to evaluate the effect of calcium oxide (CaO) particle film on sweet potato remobilization and accumulation of photoassimilates, as well as its impact on the crop yield. The experimental design was randomized blocks, with four replicates per treatment: control, 5, 10 and 15 % of CaO. In general, there was an increase for root volume; average weight per root; dry and fresh weight of roots, branches and leaves; and growth rates at 10 % of CaO. The highest yield and number of marketable roots were observed at 10 and 15 % of CaO. The use of 10 % of CaO caused an increase in the remobilization of photoassimilates and, consequently, an increase in the sweet potato yield.