Dr Rajneet Uppal1, Danielle Malcolm1
1NSW DPI, Wagga Wagga, Australia
Frost has become a major threat to Australian canola industry due to increased frequency of extreme abiotic stress events and exposure of early sown canola to greater frost risk. Significant yield loss can occur when frost events coincide with reproductive development of canola. In 2017, frost reduced canola grain yield by approximately 0.3 t/ha in NSW, a total of 120,000 tonnes valued at $63 M. Previous research on frost tolerance focus on using multiple sowing dates to create a range of flowering dates to understand frost response however, the commercial relevance of the experimental results is doubted because true ‘frost exclusion” treatment is generally missing. A replicated field experiment with two canola varieties and two temperature treatments (frosted and non-frosted) was conducted at Wagga Wagga Agricultural Institute, Wagga Wagga, Australia in 2020 to develop a method for determination of frost damage in canola crop. Purpose- built frost shelters were used to insulate canola plots in “frost exclusion’ treatment (non-frosted) and were compared with ambient temperature in control plots (frosted). Frosted and non-frosted treatments were at par for grain yield, oil quality and harvest index due to fewer frost events, lack of severe (-4°C) frosts at mid-flowering to grain -filling and compensatory effect of good in-season rainfall in 2020.