Effect of Intercropping with <i>Cocos nucifera</i> L. on the Growth and Quality of <i>Pandanus amaryllifolius</i> Roxb. in Hainan Island, China

Pandanus amaryllifolius Roxb. (pandan) and Cocos nucifera L. (coconut) are traditional economic crops widely cultivated in tropical and subtropical regions, with intercropping being common in South and Southeast Asia. However, the effect of intercropping with coconut on the growth and quality of pandan has received little attention at present. Therefore, a field experiment was conducted to evaluate the effects of intercropping modes on soil physicochemical properties, agronomic traits, photosynthetic characteristics, and volatile compound content of pandan. The results revealed that intercropping significantly enhanced soil moisture, leaf area, chlorophyll content, net photosynthetic characteristics, and carbon use efficiency of pandan. Furthermore, intercropping with coconut significantly enhanced the content of volatile compounds, including ketones, alcohols, esters, furanones, pyrroles, acids, and phenols. The increases in soil moisture, improvement in leaf structure, and enhancement of the photosynthetic process under intercropping were the primary drivers of the accumulation of volatile compounds, particularly key quality indicators such as 2-acetyl-1-pyrroline and phytol, in pandan leaves. These findings contribute to the identification of key regulatory factors for enhancing the growth and quality of pandan in intercropping mode.