Factors influencing the relative susceptibility of wheat cultivars (Triticum aestivum L) to blackpoint

Blackpoint was assessed on grain from wheat cultivars grown in eight contrasting UK sites, seasons and production systems. There were significant differences in cultivar susceptibility which were correlated with thousand grain weight in two experiments and grain width:length ratio in one experiment. Relative cultivar differences altered: at different positions in the ear; when rainfall was exceptionally low during grain filling; and when the application of a fungicide programme led to large increases in blackpoint on particular cultivars. Cultivar and fungicide effects on the isolation frequency of potential causal organisms from grain were studied in two experiments and are discussed in relation to blackpoint severity.