## 1 Introduction  
It is estimated that more than one-third of harvested fruits and vegetables worldwide are lost during postharvest handling [1]. As summarised in Figure 1, among the factors contributing to these losses, intrinsic physiological senescence and fungal pathogen infection are the most significant [2]. Specifically, the post-harvest storage period of stone fruits, such as sweet cherries and plums, is limited by various factors, including water loss, softening, surface pitting, stem browning, colour loss, and post-harvest rot [3]. Additionally, stone fruits are susceptible to the development of fungal infections throughout the supply chain, as their tissues deteriorate during prolonged storage periods, making them more susceptible to infections during shelf life (SL) [5]. In this regard, post-harvest rot is mainly caused by fungal pathogens, such as _Botrytis cinerea_ Pers. :Fr, _Monilinia_ spp., _Alternaria alternata_ (Fr. :Fr) [PERSON], _Penicillium expansum_ [PERSON], _Rhizopus stolonifer_ (Erhenb. :Fr) [PERSON], _Cladosporium_ spp. and _Mucor_ spp. [6]. For many years, synthetic fungicides have proven to be the most effective treatment for controlling post-harvest diseases in fruits and vegetables. However, their use is increasingly restricted owing to public concerns about the environmental and human health risks associated with the use of pesticides, as well as the development of resistance in fungal pathogens to fungicides. Since the 2010s, the use of synthetic fungicides to control post-harvest diseases in stone fruit has been limited to a few authorised products, namely fluidoxonil (Scholar(r)), (DeccoPyr Pot(r)), and (Xedathane 20(r)), the first of which was registered in 2015 [7]. Extremadura is a major contributor to the national plum production in Spain, accounting for more than 40% of the total output. It is also one of the primary regions for cherry production in Europe, ranking second in the national scene after the Aragon. In 2022, the Extremadura sector produced almost 4% of the cherry output in the European Union [4; 8; 9]. Figure 1: Factors contributing to the deterioration of plums and cherries before they reach the market [4]. Determining the precise extent of fruit spoilage caused by biotic and abiotic factors is a complex task. Nevertheless, several factors, such as the volume and quality of production, weather events, different types of growers, and sales destinations can influence the occurrence of spoilage [10]. A pilot study by INE from 2003 to 2006 found that approximately 20% of harvested fruits spoil before reaching consumers, showing that microorganisms are a major cause [11]. If 20% of Extremadura's losses are due to biological agents, then in 2022, about 4.5 metric tons of cherries and 15 metric tons of plums were lost. These losses are significant, as they represent produce that is unable to reach its intended points of sale due to deterioration caused by these agents. Owing to these restrictions, there is a global trend towards the development of safer and more eco-friendly alternative methods to reduce or replace the use of synthetic fungicides. In this context, the use of microbiological control agents, particularly microbial antagonists, for the treatment of post-harvest diseases shows promise as an alternative to chemical fungicides for stone fruits [12]. The use of microbial antagonists offers several advantages, including safety, persistence, low impact on the ecological balance, and compatibility with other methods. However, the major limitations of biocontrol are the lack of eradication activity and an activity spectrum narrower than that of synthetic fungicides [13]. Currently, many microbial antagonists against post-harvest diseases have been identified, and commercially available biocontrol formulations include AMYLO-X\({}^{\circledR}\) WG (_Bacillus amyloliquefaciens_ subsp.