A comparative physico-chemical study of rhizosphere soils of healthy and infected agarwood trees in Tripura, Northeast India

Agarwood is the result of the interaction of the host and endophytic microbes in the Aquilaria malaccensis Lam. tree. Consequently, oleoresinous compounds accumulated in the plant are transformed into sesquiterpenes and chromones in the endophyte-infested Agarwood plants. The research is focused on determining the relationship between soil physicochemical properties and Agarwood formation in A. malaccensis. Various physicochemical parameters of the rhizosphere soil of healthy and infected agar plants were analyzed using Pearson correlation and principal component analysis. The findings of this study indicate that the presence of endophytes in infected Agarwood plants leads to differences in soil nutrient concentrations. The infected plant rhizosphere soil shows a lower concentration of phosphorus, nitrogen, and potassium compared to healthy plant rhizosphere soil. The endophytic microorganisms in the plants must contribute to this alteration in soil. Shortage of certain nutrients in the soil may lead to decreased resistance in Agarwood plants, potentially increasing the risk of endophyte infestation and blackwood formation in the tree. This result provides crucial information about the relationship between soil properties and Agarwood production, which can help farmers augment their farming practices for the best possible results.