Juan Pablo Jordán

In a microsoms experiment, we compared maize grown in mono-, inter-, and cover-cropping arrangements profiling non-volatile and volatile secondary metabolites across leaves / roots and resulting herbivore resistance. Non-volatile profiles diverged markedly across systems while volatile compounds were largely unchanged; benzoxazinoids were upregulated under intercropping, with bean intercrop as the companion plant driving the strongest response. This work shows that diversified cropping systems fundamentally change plant secondary metabolism, which can be deliberately designed to enhance herbivore resistance.

Journal of Applied Ecology, 63, e70284 (2026)

We evaluate how commonly used seed chemical treatments — fungicides, insecticides, and biological coatings — influence the assembly and function of the rhizosphere microbiome, with downstream consequences for plant performance and belowground community dynamics. Publication in prep.

Working in Andean ecosystems, this project tests whether plant chemical diversity scales with the diversity of associated herbivores. We use field surveys and untargeted metabolomics in Baccharis latifolia to evaluate hypotheses on the maintenance of phytochemical diversity.

Functional intercropping is widely shown to increase pest resistance, but the relative contributions of direct (toxic/antidigestive) versus indirect (natural-enemy-recruiting) defenses, and their constitutive versus induced expression, remain poorly resolved. In this study, maize was paired with four companion species (alfalfa, bean, Desmodium, and red clover) and assayed for chemical defenses and herbivore performance with and without prior herbivore induction. Intercropping — particularly with Desmodium — reshaped maize chemical defenses and reduced herbivory in both no-choice bioassays and field experiments, while indirect defenses remained unchanged by intercrop or induction. We propose "intercrop-mediated induced responses" as an integrated mechanism by which diversified cropping systems generate associational resistance through shifts in both constitutive and induced secondary metabolites.

Frontiers in Plant Science, 17, 1766071 (2026)

An ongoing project investigating how intercropping with legumes shapes arbuscular mycorrhizal fungi (AMF) communities associated with maize, and how those belowground partnerships modulate inducible defenses against aboveground herbivores.