Four pillars are required to support a successful biocontrol fungus

Despite biocontrol conceptually being a useful way to control specific pests, there are very few products that are used beyond the glasshouse level, into the field. Only if organisms meet four criteria (four pillars) will they be widely used in the field to replace or augment conventional agrichemicals. (i) The virulence of the biocontrol agent must be enhanced to overcome evolutionary barriers either by mixing with synergistic chemicals or with one or more organisms, and/or by mutagenic or transgenic enhancing of virulence of the biocontrol fungus. (ii) Inoculum production must be cost-effective; many inocula are produced by expensive, labour-intensive solid-phase fermentation. (iii) Inocula must be formulated both to have long shelf life of inocula as well as being formulated to establish on, and control the target pest. Usually spores are formulated, while chopped mycelia from liquid culture are cheaper to produce and are immediately active upon application. (iv) After fulfilling these three criteria, the product must be biosafe: not produce mammalian toxins that affect users and consumers, and have a host range that does not include crops and beneficial organisms, and in most cases that it will not spread from application sites or have environmental residues beyond those needed to control the target pest. © 2023 Society of Chemical Industry.