The Effect of Protection Film on the Adaptation of ‘hanfu’ Apple Trees under Low Temperature

In this study, ‘Hanfu’ apple trees were used as a test material to determine the effect of a functional protective film on the ability of the trees to withstand temperatures below zero. The functional protective film is a quaternary copolymer prepared by emulsion polymerization of vinyl acetate (Vac), butyl acrylate (NbA), methyl methacrylate (MMA) and acrylic acid (AA). The resulting copolymer was modified by adding a thermal insulation material (ceramic powder) to enhance the insulating properties of the film. Compared with a control, application of various quantities of the protective film resulted in as much as 2.5°C decrease in the semi lethal temperature for ‘Hanfu’ trees. The insulating protective coating effectively reduced the MDA (malondialdehyde) content and significantly increased the activities of antioxidantenzyme in the tree branches, which improved the low-temperature adaptability of the plants helping them to maintain normal physiological functioning. In the four treatments, protective films with the addition of 4% and 6% thermal insulation offered better protective effects.