Quantifying the effect of ENSO on Mangosteen yield using multi-year data in Indonesia

The El Niño–Southern Oscillation (ENSO) is a major driver of inter-annual climate variability in Indonesia and has significant implications for agricultural productivity. Mangosteen (Garcinia mangostana), a perennial tropical fruit and one of Indonesia’s key export commodity, is highly sensitive to climate fluctuations. Understanding how ENSO affects mangosteen production is critical for developing climate-informed cultivation strategies. This study investigates the impact of ENSO on mangosteen production dynamics in Indonesia using provincial-scale data from 1997 to 2020, including the number of harvested plants, yield, and total annual production. The Oceanic Niño Index (ONI) was used to classify each year into El Niño, La Niña, or Neutral phases. Number of harvested plants, yield and production during El Niño and La Niña years were then compared to those of neutral years to assess ENSO-related impacts. Results show that the impact of ENSO on mangosteen varies across different regions of Indonesia. Generally, the number of harvested plants increased during El Niño years but declined during La Niña years. In contrast, yield is generally lower in both El Niño and La Niña years compared to neutral years in most production centre area except in Bali- Nusa Tenggara and Maluku- Papua. Overall production increased slightly (1–12%) during El Niño but dropped significantly (2–40%) during La Niña, indicating that excessive rainfall during La Niña has a more detrimental effect on mangosteen yields than drought during El Niño. These findings highlight the importance of ENSO monitoring as a basis for climate risk management in perennial fruit crops. Early warning systems and adaptive measures, such as irrigation planning for dry years and drainage infrastructure for wet years, are essential to mitigate ENSO-related production losses.