Phenology and South American leaf blight of polyclonal seedlings population of natural rubber trees in Colombia

Abstract

The phenological development of polyclonal rubber plantations has been little explored, although they present adaptive potential to specific biotic and abiotic conditions. Between 2016 and 2021, rubber tree seedlings were evaluated for leaf ontogeny, leaf area index (LAI), and reproductive phenology (flowers and fruits). The climatic conditions were correlated with the foliar and reproductive rubber phenology and the incidence and severity of the South American leaf blight (SALB). The tree phenology showed a relationship between defoliation-refoliation with the water deficit intensity and high temperatures. The development of the trees in a polyclonal plantation was heterogeneous, and the defoliation-refoliation phases were extended over time. A higher SALB severity was associated with higher relative humidity and radiation periods, reducing the leaf area (atypical defoliation) and changing flowering and fruiting seasonality. The intensity and duration of climatic factors, particularly water deficit, are important for determining phenological processes and fungal diseases such as SALB, which serves as a tool to build management strategies both in seed production and obtaining latex in scenarios of climate change.