title: Post-head-emergence frost in wheat and barley: defining the problem, assessing the damage, and identifying resistance.
abstract: Radiant frost is a significant production constraint to wheat (Triticum aestivum) and barley (Hordeum vulgare), particularly in regions where spring-habit cereals are grown through winter, maturing in spring. However, damage to winter-habit cereals in reproductive stages is also reported. Crops are particularly susceptible to frost once awns or spikes emerge from the protection of the flag leaf sheath. Post-head-emergence frost (PHEF) is a problem distinct from other cold-mediated production constraints. To date, useful increased PHEF resistance in cereals has not been identified. Given the renewed interest in reproductive frost damage in cereals, it is timely to review the problem. Here we update the extent and impacts of PHEF and document current management options to combat this challenge. We clarify terminology useful for discussing PHEF in relation to chilling and other freezing stresses. We discuss problems characterizing radiant frost, the environmental conditions leading to PHEF damage, and the effects of frost at different growth stages. PHEF resistant cultivars would be highly desirable, to both reduce the incidence of direct frost damage and to allow the timing of crop maturity to be managed to maximize yield potential. A framework of potential adaptation mechanisms is outlined. Clarification of these critical issues will sharpen research focus, improving opportunities to identify genetic sources for improved PHEF resistance.
authors: Department of Agriculture and Fisheries Queensland, Leslie Research Facility, PO Box 2282 Toowoomba, QLD 4350, Australia The University of Southern Queensland, Centre for Crop Health, West St, Toowoomba, QLD 4370, Australia troy.frederiks@qld.gov.au.
authors: T M
authors: TM
authors: Frederiks
authors: The University of Queensland, Queensland Alliance for Agriculture and Food Innovation, Leslie Research Facility, PO Box 2282 Toowoomba, QLD 4350, Australia.
authors: J T
authors: JT
authors: Christopher
authors: The University of Southern Queensland, Centre for Crop Health, West St, Toowoomba, QLD 4370, Australia.
authors: M W
authors: MW
authors: Sutherland
authors: The University of Queensland, Queensland Alliance for Agriculture and Food Innovation, Hermitage Research Facility, 604 Yangan Road, via Warwick, QLD 4370, Australia.
authors: A K
authors: AK
authors: Borrell
mesh_terms: D000222:Adaptation, Physiological; D004777:Environment; D005615:Freezing; D001467:Hordeum / Q000502:physiology*; D013312:Stress, Physiological; D014908:Triticum / Q000502:physiology*
keywords: Barley; frost; reproductive frost; spring radiant frost; wheat.