Carting grain west of Esperance this week. Photo: Paul Carmody

MILD temperatures in the lead-up to harvest have boosted yield potential for Western Australian crops now being harvested and forecast by the Grain Industry Association of WA in its October crop report out today to yield a total of 23.93 million tonnes (Mt).

The forecast is up 870,000t from the 23.06Mt forecast by GIWA in previous report released September 18, with increased production estimates for wheat and barley, along with modest lifts for oats and lupins, more than offsetting a 179,500t cut to the canola forecast.

Report author Michael Lamond said the result was achieved despite limited September rainfall outside the Great Southern and Esperance regions.

He said below-average temperatures had “allowed crops to slowly fill potential yields where subsoil moisture was available”.

“Mild temperatures during grain fill do not have quite the same impact as rainfall, but without substantial heat shock during grain fill, crops usually end up yielding more than appearances suggest,” Mr Lamond said in the report.

“There were several days near the end of September where temperatures nudged 30 degrees Celsius with hot winds, scorching crops and sending them white overnight.

“However, the majority of crops seemed to push through this and have benefited from the slow dry-down.

Mr Lamond said mild temperatures would benefit wheat the most, particularly later-emerging crops.

“All crops in the low growing-season rainfall strip from the western Kwinana South port zone down through the eastern portion of the Albany port zone will also benefit from the rain in early September, and mild conditions through the majority of the month and into early October.”

Mixed quality, canola concerns

Grain quality in cereals was “likely to be all over the place”, according to Mr Lamond, with “high screenings where crops ran out of moisture, to good weights where the crops were less impacted”.

“There is likely to be a high variance in protein from the array of fertiliser strategies employed during the year as growers juggled decision making around restricted nitrogen availability and high cost, along with the difficulty of estimating the impact the long dry spell experienced in May and early June would have on overall yield potential.”

Michael Lamond.

Mr Lamond said canola production prospects had weakened since last month, with the estimate now down to 4.6Mt.

He said this was due to the “the issue of poor pod development in many canola crops across the state”.

“Poor pod set on the main raceme is going to take the top off potential yields in those crops most affected, and the widespread nature of this impact will keep a lid on total canola production.”

Near-record early yields

Mr Lamond said early harvest yields across port zones ranged from “near record” to “solid” at harvesting kick-off.

“Early harvest grain yield results coming in from Geraldton and Esperance are very good, although skewed as growers hop into the best paddocks first.

“Even so, Esperance is going to have near record tonnages and the better areas and soil types in the Geraldton port zone are going to be very good.

“The central regions of the Kwinana port zone are going to be near record yields and the lower-rainfall regions of the Kwinana East port zone are also going to be very good.

“The western areas of the Albany port zone are going to be solid again, as are the south coastal regions.”

Further detail on crop conditions in individual WA port zones can be found as part of the full report on the GIWA website.

Source: GIWA