Pre-harvest sprouting in cereals: Global incidence, impacts and mitigation strategies

Context

Pre-harvest sprouting (PHS) is a pervasive threat to cereal production, adversely affecting yield, grain quality, and economic return. While numerous studies have investigated PHS in specific crops or regions, a comprehensive synthesis of the climatic drivers, crop-specific susceptibilities, and mitigation strategies across cereals remains lacking, especially under the context of intensifying weather extremes due to climate change.

Objective

This study aimed to: (1) identify key meteorological conditions associated with PHS events in cereal crops; (2) assess the impacts of PHS on grain quality and yield across major cereals; and (3) evaluate the effectiveness of genetic, agronomic, and chemical interventions to mitigate PHS incidence.

Methods

We conducted a global meta-analysis to quantify effect sizes of PHS incidence, quality degradation, and mitigation outcomes using data from 101 peer-reviewed articles and 65 media reports, covering five major cereals (rice, wheat, barley, sorghum, and maize).

Results and conclusions

PHS risk was strongly associated with 2–6 consecutive days of moderate rainfall (3–29 mm/day) and crop-specific temperature thresholds. Rice and sorghum were more vulnerable under warm, humid conditions, while wheat and barley exhibited greater susceptibility in cooler environments. PHS significantly degraded grain quality: in rice, polished grain rate declined by 22.5 % and chalkiness increased by 53.8 %; in wheat, falling number dropped by 71.8 % and gluten strength also declined. Genotypic variation played a substantial role: tolerant genotypes had less than half the PHS incidence of sensitive ones. Among mitigation strategies, exogenous abscisic acid (ABA) and hormonal inhibitors reduced PHS incidence by up to 81.8 %, though efficacy diminished with prolonged wet conditions.

Significance

Our findings underscore the multifaceted nature of PHS and its growing relevance under climate change. Integrated strategies—combining resistant cultivar deployment, optimized agronomic practices, and timely chemical applications—are essential for mitigating PHS risk. Context-specific adaptation, guided by meteorological thresholds and crop phenology, will be critical for sustaining grain quality and yield across global cereal production systems in an era of climatic uncertainty.