WITH the majority of the huge volume of grain still in the paddock, harvest in Western Australia has been a stop-start affair due to continued rainfall events and the unseasonal cool conditions slowing down the finish of crops.
According to the Grain Industry Association of WA's (GIWA) November Crop Report, released last Friday, growers are finding all crops are yielding better than expected except for the badly frosted areas in the north-eastern and far eastern regions of the State.
As a result the October estimate of 19.2 million tonnes has been upgraded to 20.5mt.
Report author Michael Lamond said the cool conditions in spring have had a major impact on allowing crops to fill heads and add weight in all regions.
"Heat shock in the spring is usually the limiting factor with grain yield and the lack of it this year has had a staggering effect on the ability of crops to finish, even where there was very little finishing rainfall," Mr Lamond said.
"The full impact of the frosts across large areas of the central graingrowing regions and more recently in the southern regions is still unknown, although it is now clear there will be more grain around than estimated a month ago.
"In all regions where harvesting has been underway for a few weeks, canola crops are yielding higher than expected even where there were losses from the repeated wind events over the last few weeks and total production could end up just short of three million tonnes."
Cereal crops are yielding better than expected although results so far are mainly from the better paddocks, while lupin, pulse and oat grain yields will all be above average.
There have been a series of storm events that have caused significant loss from hail in strips and although the overall impact on total grain production for WA will be minimal, grain quality is starting to be impacted by the wet conditions and will start to slide if it continues.
In the Geraldton zone harvesting has been underway for several weeks but growers have been held up with repeated rainfall events and are behind where they would like to be at this time of the year.
Many areas have now had up to three separate rainfall events since harvest commenced and due to the stormy nature of these events, some have received over 100 millimetres.
Mr Lamond said the repeated rain, hail in strips and wind has had an impact on reducing canola grain yields from all paddocks.
"This is particularly evident in the early sown paddocks due to pod loss, hence the really top end results were not achieved, but the later sown paddocks however have generally yielded more than expected," he said.
"The wheat that has been harvested is going well over what was estimated prior to harvest with the relatively cool finish to the season for the region having had a major impact on the ability of cereal crops to fill heads.
"With multiple rainfall events already, if there is more rain over harvest, it is likely that downgrades in wheat quality will start to occur."
However, the overall net result is still a very good outcome considering the lack of finishing rain and unfavourable weather during harvest.
In Kwinana North Midlands, canola grain yields so far have been very good with the better areas going 1.8 to 2.6 tonnes per hectare with oil content in the mid 40s and up to 48 per cent.
The wind and isolated hail events have knocked the top off canola grain yields, and some areas also got very wet in winter in the higher rainfall regions, but taking all this into account, growers are pretty happy with the end result.
Mr Lamond said in the Kwinana South region, it has mostly been canola and some barley harvested to date.
"The recent rain has been frustrating because, like other areas further north, crops were too advanced to benefit and the loss in canola crops from pod shatter continues to mount," he said.
"Even so, the better crops in the higher rainfall regions are going 3t/ha over large areas and barley has been yielding in the 5t/ha range even with the wet areas included."
Canola crops are yielding above expectations for most growers in Kwinana North East and there are plenty of 2t/ha whole paddock averages coming in, even where there was substantial pod loss from wind events.
Barley has been good where not frosted, but even in the frosted areas wheat and barley have recovered to some extent where there were reserves of subsoil moisture and grain yields a little more than expected.
In Albany West, the general comment is that while the wet areas are substantial, the good areas are very good and will help to keep paddock averages up.
Small areas have been harvested to date with barley that looks like 3t/ha going 4.5t/ha and canola 2.5t/ha to 3t/ha.
However, these are the best paddocks and average paddock yields will come off a bit as more area gets harvested.
Mr Lamond said harvest was just getting going in Albany South and early indications were that grain yields were going to be above average for all areas away from the coast.
"Recovery from the waterlogging has been substantial although whole paddock averages are going to be impacted by the poor spots," he said.
"The resown areas could end up with barley grain yields of greater than 3t/ha and away from the coast and waterlogged areas to the west, barley and canola yields have so far come in well above expectations.
"Wheat crops are still filling heads and are benefiting from the subsoil moisture reserves and cool conditions, with many now filling five grains wide and those that escaped the frost looking very good."
The Lakes region in the Albany zone is still set for one of the best results for a long time, with early start, good rainfall, lack of frost and now cool finish having all contributed to the region expecting up to 50pc higher grain yields than average for all crops.
Only small areas of crop have been harvested so far, but crop estimates for barley, wheat and milling oats look to be 3t/ha plus and canola 2t/ha plus in the better spots.
Harvesting is still in its early days in the Esperance port zone, although it is already looking like the region is on target for a record or close to record tonnage.
Wheat and barley grain yields have been very good in the drier areas of the zone and canola is excellent as well, however there are areas of frost and more recently hail that has significantly impacted crops in isolated spots.
"Some canola crops have lost up to 500kg/ha from repeated wind events although in the drier areas they are still going 1.2 to 1.3t/ha and the wetter areas are going a solid 3t/ha for the better crops," Mr Lamond said.
"Wheat has benefited the most from the cool finish and pre-harvest estimates are all above average for the different regions in the zone.
"For some crops, based on head size and slow grain fill, grain yields could be well above average."
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