“…The potential of symbiotic N 2 fixation and other major positive plant microbial interactions in agricultural systems such as mycorrhizas and grass fungal endophytes was considered further in a separate Special Issue of Annals of Applied Biology ‘Positive plant microbial interactions’ (Andrews et al ., ). Also, in his Editorial , Valkonen () emphasised the importance of understanding the interactions between plants, microorganisms and invertebrate animals if integrated pest management is to be successful in the improvement of crop productivity.…”