RAINFALL at the start of August was a game changer for the 2020 growing season, according to the latest Grain Industry Association of Western Australia's (GIWA) crop report, released last Friday.
Widespread falls from August 7-9 greatly increased the chances of most farmers having at least an average year.
The rain of that weekend was preceded by a large deluge in the south coastal areas earlier in that week, with many growers commenting that before those rains, crops were starting to go backwards.
The timely falls resulted in GIWA's first production estimate for the season to hit 14.9 million tonnes, which is just 300,000t short of WA's 15.29mt five-year average.
Crop report author Michael Lamond said for some regions, the rain will halt the slide in grain yield potential that was occurring, but for most it will push grain yield potential up.
"The combination of the very warm winter and rapid crop growth has brought crop flowering forward by at least two weeks from where it would normally be from a late May break," Mr Lamond said.
"On the upside this means less chance of heat shock in the spring, on the downside there is more chance of frost risk over the next few weeks.
"An additional risk factor is the lack of sub-soil moisture in a lot of areas where crops have sucked the soil profile dry with the exceptional growing conditions during the winter."
A record area of crop of close to 8.5 million hectares has been planted, with a lot of the extra area going down in the potentially better yielding regions west of the Albany Highway and areas of the South Coast.
In the Geraldton port zone, the recent rainfall has turned the outlook around with most of the zone receiving more than 20 millimetre of rainfall.
"Crops were melting away and could not have gone much longer without rain," Mr Lamond said.
"The rainfall in the eastern areas on the heavy country has stopped the yield decline whilst for the remainder of the zone has at least held the final grain yield potential of crops.
"In the eastern fringes of the zone, wheat was pushing up heads and dropping tillers with crops on the lighter country to the west starting to stress from lack of moisture."
The rainfall in Kwinana North Midlands has recovered the potential grain yield in the dry corridor running north to south in the centre of the region.
Mr Lamond said that prior to the rain on the weekend, the rainfall split the region in half with the better areas to the west having twice as much rainfall as directly adjacent to the east.
"Further east, the summer rains have kept crops ticking along until this last series of fronts," he said.
"The crops in the areas that did receive the summer rain are now set up for at least average grain yields.
"The west coastal regions have been light on for rain all year and whilst the nitrogen use efficiencies have been exceptional from the lack of leaching rains, more is needed to reach average grain yield potential."
For Kwinana South, the two rainfall events of 10 to 25mm in the first week of August, followed by a further 10 to 15mm a week later, has turned the season around just in time.
For individual growers who received higher totals of summer rain, grain yield potential is as good as 2018 which was a record production year for the region
There are crops with some terrific potential in the lower rainfall regions of Kwinana North West that received the summer storms, however growers on either side have been a bit light on for rain during the winter and will need a good spring to hit average grain yields.
The West Albany area is shaping up to be similar to last year for potential grain production.
Total winter rainfall has been below average, although this has resulted in less waterlogging and very few areas of the zone are showing crop stress from this at the moment.
Mr Lamond said crops have bulked up well and would be better able to handle any waterlogging that occurs from now on.
"The zone will still need some good rains in spring to finish crops off and dodge the frost to hit the yield levels of the last two years," he said.
"With top end grain yield potential high, it is shaping up to be a very good year for growers in the region if the season goes their way."
The season for many in Albany South has turned around with falls of between 30mm to 200mm in early August.
"For many in the epicentre of the "no rain" area south east of the Stirling Ranges, it was their best rain for a couple of years and has halted the run of record low rainfall," Mr Lamond said.
"It is incredible what one rain event can do, with some areas of the zone going from the driest July/August period to the wettest on record.
"Many growers received surface run-off to put some water in dams that have been dry for three years, but pasture is still tight for most."
Albany South had been experiencing a good year with excellent crop growth from the good start and small regularly spaced rainfall.
The crops were just starting to run out of moisture and showing the signs of stress prior to the rain at the beginning of the month, however the potential is still there for a well above average year, but the next month will decide.
Grain yield potential for the Esperance zone is incredibly varied, with the various sub-zones in the region having widely different potential.
Mr Lamond said the western strip from Ravensthorpe north, currently has above average grain yield potential and areas closer to the coast are good from the lack of waterlogging.
"The central regions north of town have picked up some good falls of rain and are now on track for at least average grain yields for all crops," he said.
"Areas around Salmon Gums, Grass Patch and Cascade missed out on the dump of rain that areas to the west received in early August.
"Most of the zone only received light rainfall from the most recent fronts that passed across the State last week."
Mr Lamond said around WA barley production would be well down due to less area planted.
"The majority of the reduction in barley plantings went to wheat and this could see wheat tonnage exceed 60 per cent of total grain production for the State for the first time in many years," he said.
"Canola plantings are mainly in the medium to high rainfall regions and even though many suffered from difficult establishment conditions, most have picked up in the warm growing conditions.
"Oat crops were the first to feel the pinch in the recent drying conditions which is expected to put a cap on potential yield, however overall oat area is up from 2019."
The final tonnage could still vary based on the split between hay and grain which will not clear for another month, while lupin tonnage will struggle to exceed the estimates due to the reduction in area and later start to the season.
