Figure 2

Enzyme treatment on BP films spread in a pipe house. (a) Weight reduction of various BP films. − : without treatment, + : enzyme treatment. Asterisks indicate that the data compared were significantly different (n = 6; t-test; ** p < 0.01, * p < 0.05). Effect of various calcium carbonates as enzyme stabilisers. (b) Images of the films the day after enzyme treatment, (c) total area of holes, and (d) number of holes in the films^§. (e) Distribution of holes in the films. The holes are shown in green, and the distribution of the holes is shown by connecting the holes with magenta lines. C indicates without enzyme treatment, L, M, and S indicate treatment with heavy calcium carbonates of large, medium, and small particle sizes, respectively. “Precipitated” indicates treatment with precipitated calcium carbonate. (c) Values calculated based on the pixels of the images. Letters above multiple columns indicate that the values were significant (p < 0.05; n = 3) according to analysis of variance (ANOVA) using Tukey’s post-hoc test. ^§We have been granted a patent for using PaE to accelerate the degradation of biodegradable mulch films laid in the field, for calcium carbonate to increase the effect, and for calcium carbonate to be more effective with smaller particle size²⁷. The test examples in the specification include one each of the films shown in (b) treated with enzymes alone, enzymes, and large or small particle size calcium carbonate.