Effects of shading intensity on growth and quality of Artemisia stolonifera

Abstract

The purpose of this study was to analyze the effects of shading intensity on the growth, yield, and quality of Artemisia stolonifera so as to provide references for the artificial cultivation of A. stolonifera. The seedlings of A. stolonifera with consistent growth underwent shading treatment at four shading intensity levels(0, 55%, 85%, and 95%) with different layers of black shading nets. The agronomic indexes, yield, moxa yield, total ash, quality characteristics of moxa during combustion and pyrolysis, main volatile components, flavonoids, and phenolic acids were measured. The results showed that under shading conditions, the stem diameter, leaf width, 5-leaf spacing, branch number, and yield of A. stolonifera decreased significantly, while the plant height, leaf length, leaf number, chlorophyll content, and moxa yield increased first and then decreased with the increase in shading intensity. The burning performance of moxa under natural light was better than that under moderate and severe shading conditions. The content of eucalyptol first increased and then decreased with the increase in shading intensity. The humulene content was negatively correlated with shading intensity. Other major volatile components showed no significant difference under various shading conditions. The content of neochlorogenic acid, cryptochlorogenic acid, isoschaftoside, and isochlorogenic acid B was positively correlated with shading intensity, while the content of chlorogenic acid, isochlorogenic acid A, and isochlorogenic acid C decreased first and then increased with the increase in shading intensity. To sum up, A. stolonifera is a light-loving plant, and shading can greatly reduce the yield, the content of internal components, and the burning performance of moxa. It is the main reason why A. stolonifera is mainly distributed in the forest edge, open forest, roadside, and wasteland grass in the middle and high mountains in the wild. For artificial domestication and cultivation of A. stolonifera, it is better to select plots with sufficient light.