Manganese dioxide (MnO 2 ), as a catalyst in composting processes, can accumulate in soil over multiple fertilization. However, its impact on crop growth remains to be explored. In this study, a pot experiment was conducted to investigate the impacts of MnO 2 on the tomato plant performance across various growth stages. Results showed that MnO 2 reduced the plant height, leaf number and length by 35.53 %, 27.61 %, and 37.00 %, respectively, and decreased the fruit weight (23.16 %) and sugar-acid ratio (29.7 %) of fruits compared to the MnO 2 -free control. The adverse impacts of MnO 2 on plant growth might be attributed to the inhibition of microbial activity in soil reflected by the reduction of soil urease (9.30 %) and acid phosphatase (12.52 %) activities, which decreased the efficiency of nutrients conversion and uptake. The decrease of nutrient elements in roots resulted in oxidative stress in the plant, inhibiting the plasma membrane H + -ATPase activity thereby reducing the translocation of nutrients (e.g., calcium, magnesium, and phosphorus) translocation from roots to leaves. Furthermore, the phytohormones indolebutyric acid, gibberellin, and jasmonic acid of leaves were disturbed. This study reveals the risks associated with the application of MnO 2 -containing organic fertilizers.
The effect of cold plasma (CP) treatment on the degradation of anilazine fungicide in tomato juice was investigated. Anilazine solution of 5 mg/L was added to tomato juice samples and treated using a dielectric barrier discharge (DBD) cold plasma (CP) system with exposure times of 0, 1, 2, 3, 4 and 5 min. The gas chromatography-mass spectrometry (GC-MS) results showed that the reduction in anilazine in the tomato juice achieved 47% and 65% after treatments for 4 min and 5 min, respectively. The concentration of anilazine decreased significantly ( P ≤ 0.05) with an increase in treatment time. Analysis of the quality attributes of tomato juice treated for 5 min showed that the quality of the treated juice remained acceptable with a slight decrease in pH from 4.28 to 4.18, an increase in total soluble solids (TSS) from 5.70 to 6.70 ◦ Brix, an increase in the browning index from 2.35 to 4.54, a very low (but within the acceptable limit) total colour difference, and only minor changes in antioxidant capacity, total flavonoid and total phenolic content, as compared with the control samples. These results indicated that DBD cold plasma treatment could be an effective and rapid technique to degrade pesticide residues for the fruit juice industry.
危险品化学品经营许可证（带存储）