Effects of aging, climatic, physical factors, and site on quality parameters of the bark of black wattle ( <i>Acacia mearnsii</i> de Wild.)

Abstract Black wattle ( Acacia mearnsii De Wild.) is a key tree crop in South Africa, valued for its bark and timber, both of which contribute significantly to export revenue. Wattle bark harvesting begins with the rainy season in September and extends to May. During this time, harvested bark is transported to three processing facilities. The journey, which includes stripping and transit and lasts for several days, exposes the bark to varying environmental conditions, such as temperature, rainfall, humidity, and light, all of which can influence the quality of the bark. The decrease in extractives, darkening of the bark, and loss of tannins are all examples of bark quality degradation. To replicate postharvest conditions, experiments were conducted using fresh bark samples collected bimonthly from September 2020 to July 2021. These samples were subjected to varying temperature, light, and moisture conditions to simulate real‐life scenarios and quantify the extent of bark quality degradation. Quality parameters, including total extractives, tannin content, and Lovibond color were analyzed. Advanced statistical techniques, such as principal component analysis (PCA) and redundancy analysis (RDA), were used to identify patterns and relationships among variables. The findings revealed that seasonal changes and site‐specific conditions influenced bark quality significantly, particularly affecting Lovibond color, a key quality indicator. This study underscores the impact of pre‐extraction environmental conditions on the quality of bark extractives. It is essential to develop strategies to mitigate these effects in order to minimize variability and ensure consistent production of high‐quality products. The study also highlights the need for more in‐depth work in the future.