Presenter: Paul Petrie
Frost is a significant hazard to grape production in Australia, and research suggests that the frost season may be becoming longer in many grapegrowing regions. There are two types of frost: radiation frosts, which generally occur on clear nights, and advection frosts where a cold air mass moves into a vineyard. Management options for radiation frosts include ensuring that the inter-row area is closely mown, and the soil is moist and firm. A radiation frost can be predicted based on the temperature during the late afternoon when the sky is clear, and this knowledge used to arrange control measures including helicopters and frost sprinkler systems. Understanding the impact of inversion layer height and ‘strength’ is critical for the effective use of helicopters and wind machines. The management choices for advection frosts are far fewer, with overhead sprinkler systems the only proven option. Another way to reduce the likelihood of frost damage is pruning in late spring (after budburst), to delay bud break into a period when frosts are less likely to occur.
