Wood vinegar, a by-product of wood pyrolysis, is mostly discarded. Wood vinegar has a phytotoxic effect and could be potentially used as a naturally derived herbicide for weed control. The objective of this research was to evaluate the efficacy of wood vinegar from the pyrolysis of apple (Malus × domestica Borkh.) tree branch wastes to control weeds. The wood vinegar concentrations required to inhibit 50% motherwort (Leonurus cardiaca L.), redroot pigweed (Amaranthus retroflexus L.), Spanish needles (Bidens pilosa L.), and tall fescue (Festuca arundinacea L.) seed germination measured 0.51%, 0.48%, 0.16%, and 1.1%, respectively. The wood vinegar application rates (spray volume) required to provide 50% control of motherwort and Spanish needles measured 1911 L ha⁻¹ and 653 L ha⁻¹, respectively, while the highest evaluated rate at 4000 L ha⁻¹ controlled 35% tall fescue by 10 days after treatment (DAT). Common purslane (Portulaca oleracea L.) control increased as the wood vinegar application rate increased from 500 L ha⁻¹ to 2000 L ha⁻¹. Wood vinegar was more effective in dark than light conditions for controlling common purslane. By 5 DAT, averaged over application rates, wood vinegar provided 95% and 87% control of common purslane in dark and light conditions, respectively. These findings suggest that wood vinegar obtained from the pyrolysis of apple tree branches could be used for weed management.

Tea has become one of the most popular drinks worldwide because of its special taste and health benefits. ‘Yuhua’ tea is a famous specialty of Nanjing, China, a green tea produced from Camelia sinensis. It belongs to the green tea category and is one of the top ten most famous teas in China. The physical and chemical properties of soil are very important to the quality of tea. However, at present, there are few instances of research on the soil of the ‘Yuhua’ tea cultivation area. To provide the theoretical basis for improving the final quality of ‘Yuhua’ tea by soil management measures, the effects of the soil’s physical and chemical properties on the contents of important chemical components (free amino acids, tea polyphenols, and caffeine) of ‘Yuhua’ tea in three different cultivation areas in Nanjing were studied. The quality of ‘Yuhua’ tea is greatly influenced by the physical and chemical properties of the soil in which the tea plant grows. The free amino acid content and tea polyphenol content of tea leaves were significantly and negatively correlated with soil bulk density, pH, and water-soluble calcium content, while a significantly positive correlation was noticed between the two criteria and soil effective nitrogen, phosphorus, and potassium content. Additionally, the growth of the tea tree will be hampered and perhaps stressed if the soil’s helpful mineral concentration is too low. The tea tree may produce more caffeine as a result, which could lower the quality of the tea leaves. Therefore, implementing targeted soil management techniques is the key to promoting tea tree growth and improving tea quality. This study laid the foundation for the adoption of corresponding soil management measures to improve the quality of ‘Yuhua’ tea.