Comparison of three methods to assess pre-harvest sprouting in wheat

Abstract

Pre-harvest sprouting (PHS) in wheat (Triticum aestivum L.) is an increasing concern, as climate variability alters rainfall patterns and air temperatures during harvest, intensifying risk in many cereal-producing regions. The untimely germination of the grain, PHS, is caused by germination of the grain in the spike before harvesting and leads to alpha-amylase synthesis, reduced falling number, and lower grain yield and quality. Despite widespread use, the relationships between visual assessment, falling number, and alpha-amylase assays remain inconsistent. This study, conducted over two seasons (2021–2022) at two sites in the Eastern Cape, South Africa, evaluated commercially available wheat cultivars using the three PHS assessment methods listed above. Visual scores ranged from 1 (no sprouting) to 8 (fully sprouted), while falling number and alpha-amylase were analysed using standardised protocols. Correlations (p < 0.05) were observed between falling number and alpha-amylase but not between visual assessment and biochemical assays. The results highlight the fact that the three methods apply to different stages of germination. Visual scoring provides additional information to biochemical tests and is valuable in a multi-method screening protocol. This approach would enhance the accuracy and consistency of PHS evaluation in local breeding programmes and quality control under increasingly variable climates.