Impact of Different Film Mulching on the Photosynthetic Characteristics and the Yield of Sweet Potato Varieties

Purposes The experiment was to choose the best mulching method and provide a theoretical basis of high-yield cultivation of sweet potato.Methods We tested the yield and the photosynthetic characteristics related indicators of leaves and carried out the relevance analysis, using the straw and soil, black plastic film, and transparent plastic film as the mulching during cultivation of ‘Rongshu-819’.Results (1) The yield of the treatment with the black plastic film mulching was the highest, the transparent plastic film treatment lower, and the straw and soil treatment was the lowest. (2) The yield of three treatments all had extremely significant positive correlations with net photosynthesis rate(P_n), intercellular CO₂ concentration(C_i) and the contents of chlorophyll, significant positive correlations with transpiration rate(T_r). (3) In three treatments, P_n all had extremely significant positive correlations with C_i, T_r and the contents of chlorophyll, positive correlations with water use efficiency(WUE), and significant negative correlations with stomatal resistance(S_r).Conclusion In this experiment, we concluded that the black plastic film could be used as the mulching in production, which could increase P_n and the yield of sweet potatoes.