Vol:.(1234567890) Vegetos (2025) 38:314–328 https://doi.org/10.1007/s42535-023-00787-y RESEARCH ARTICLES Impact of drought stress on basal stem rot (BSR) disease development in oil palm seedlings Mohd Amar Shafiq Saipol Anuar 1  · Syd Ali Nusaibah 1  · Bee Keat Neoh 2 Received: 16 December 2022 / Revised: 24 October 2023 / Accepted: 29 November 2023 / Published online: 17 January 2024 © The Author(s) under exclusive licence to Society for Plant Research 2024 Abstract Oil palm is the most prominent high-yielding multipurpose oil crop available to date. Malaysia is ranked as the second larg- est producer of palm oil products (28%), after Indonesia (57%), with more than 21.2 million metric tonnes of production in 2019. The increasing demand for palm oil products leads to various research and developments to enhance palm yield. Unfortunately, climate change that results in drought affects the commodity crop directly. In addition to drought, a devastat- ing catastrophe hampering the Malaysian oil palm is basal stem rot (BSR) disease. Therefore, the interactions between these two stresses were investigated under nursery experiments to foresee their impacts on the oil palm industry. The experiment revealed that combined stresses on oil palm seedlings had the greatest impact when compared to single-stress seedlings. In terms of peroxidase (PO), polyphenol oxidase (PPO) and total phenolic compound (TPC) induction, which have been identified as biochemical defenses against biotic stress, were not interrupted by drought stress except for the induction of the PPO enzyme. While the proline level was interrupted by basal stem rot (BSR), demonstrating an overcoming factor of the drought stress in BSR-diseased seedlings. Keywords Basal stem rot · Drought · Oil palm · Peroxidase · Polyphenol oxidase · Total phenolic content Abbreviations PO Peroxidase PPO Polyphenol oxidase TPC Total phenolic compound BSR Basal stem rot CPO Crude palm oil FFB Fresh fruit bunch RCBD Randomized complete block design PDA Potato dextrose agar PDB Potato dextrose broth MAI Months after inoculation DI Disease incidence DS Disease severity PS Polystyrene PVP Polyvynil pyrrolidone GAE Gallic acid equivalents Introduction Oil palm was introduced as a commodity crop in Malaysia and Indonesia due to its wet and humid climate (Basiron 2007). The growth of this crop, however, is influenced sig- nificantly by rainfall (Tui and Arifin 2013). Unfortunately, rainfall distribution in Peninsular Malaysia, particularly in inland areas, is uneven, thus demonstrating a substan- tial effect on the growth and production of oil palm (Tui and Arifin 2013). Drought directly affects oil palm yield by reducing the number of fresh fruit bunch (FFB) through changes in the ratio of female to male inflorences (Corley and Hong 1982). El Nino, which started in March 2015 until May 2016 (lasted for over 15 months) in Peninsular Malaysia had resulted in a significant decrease in crude palm oil (CPO) production (Amirul et al. 2016). The severe phe- nomenon (categorised as ‘very strong’) caused a significant loss in FFB yield and CPO production of about 10–16% and 8–14%, respectively (Amirul et al. 2016). In addition to drought, a prolonged threat to the sustainability of oil palm is BSR disease caused by Ganoderma spp., which is also a vital concern in cultivating sustainable palm oil production (Peng et al. 2019; Purba et al. 2019). BSR causes white rot in oil palm with an estimated total yield loss by reducing * Syd Ali Nusaibah nusaibah@upm.edu.my 1 Department of Plant Protection, Faculty of Agriculture, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia 2 Sime Darby Technology Centre, Lebuh Silikon, Universiti Putra Malaysia, Serdang, Selangor, Malaysia