Winter rainfall was average to above average in most cropping areas in Western Australia. Many locations had more winter rainfall this year the previous 20 winters. This followed a timely season break in late May, and means that most crops in Western Australia were in good to excellent condition at the start of spring with good prospects for high yields. The favourable conditions over winter mean that many crops are expected to achieve good yields even without further significant rainfall. If average rainfall is received over spring, there is considerable upside potential, especially for cereal crops. Frost events and prolonged above average temperatures do present a downside risk to yields. However, many crops have developed at a slower than average rate this year, which will somewhat mitigate the risk of damage from any frost events but could increase the risk of heat stress during spring if warmer and drier than average seasonal conditions occur.
According to the latest three-month climate outlook (September to November), issued by the Bureau of Meteorology on 30 August 2018, below average spring rainfall is likely in cropping regions in Western Australia. It is likely that maximum and minimum temperatures will exceed median during spring.
Winter crop production in Western Australia is forecast to rise by 12% in 2018–19 to 16.3 million tonnes, driven by forecast rises in wheat and barley production.
Wheat production is forecast to increase by 21% to 9.6 million tonnes in 2018–19. An average yield of around 2.0 tonnes a hectare is expected, which reflects favourable crop prospects in most areas of the state.
Barley production is forecast to increase by 4% to 3.9 million tonnes. The average yield is forecast to decrease slightly compared to 2017–18. The average barley yield in 2017–18 was the second-highest on record for Western Australia, and is unlikely to be achieved again given the 8% rise in planted area in 2018–19.
Canola production is forecast to decrease by 17% to 1.6 million tonnes. This reflects both an 8% fall in planted area and a 10% decrease in the average yield following a poorer start and less favourable early growing conditions for canola.
Table 12 Winter crop forecasts, Western Australia, 2018–19
Note: Yields are based on area planted.