The rubber tree, Hevea brasiliensis (Willd. ex A. Juss.) Mull. Arg., is one of the most economically important industrial crops, producing the milky latex which is the source of the valuable global commodity natural rubber. Natural rubber provides a source of income for rural communities, especially in Southeast Asia (Singh et al., 2021;Vongkhamheng et al., 2016). Due to the high demand globally for rubber, the area of rubber plantations worldwide increased gradually from 3 million ha in 1961 to 12 million ha in 2019 (FAO 2022).Approximately 90% of global rubber production is dominated by smallholders and planted in monoculture (IRSG, International Rubber Study Group, 2019). A rubber small-holding is defined as contiguous or non-contiguous areas aggregating less than 40.47 hectares (100 acres) planted with the crop (Saufe & Man, 2017). 2021) reported that 96% of rubber production yields are explained by independent variables comprising labour, plantation area, weeding and other cultivation activities by the smallholders.
Ramli et al. (In addition, the income of the smallholder farmers also determines rubber production at the local scale, where low profitability leads to reduced tapping activities and even abandonment of farms (Ali et al., 2021). The conversion of primary and secondary forests to rubber monoculture decreases species richness and impacts overall species composition (Gitz et al., 2020). The introduction of this monoculture to new ecosystems has also led to the spread of nonnative pathogens and diseases (Monkai et al., 2017). Arguably, the most economically important rubber disease is white root rot (WRR) disease.