Mixed outlooks at start of the season

Inconsistent falls and storms around Anzac Day proved beneficial in the south and central areas that received rain, germinating dry sown crops, while northern and central west regions weren't so lucky.

The report said the rainfall that did occur was driven by thunderstorms rather than cold fronts and consequently was brilliant for some and simply a nuisance for others.

"Growers that did receive rainfall in the lighter end of the rain gauge and who have little subsoil moisture underneath, now face the risk of a "false break" unless there is follow up rain soon," the report said.

"Where there were heavier falls, particularly where the moisture was able to meet up with subsoil moisture, crops will be ok for the time being."

The report acknowledges it is early in the season and there is still time for good breaking rain.

"The current conditions have growers increasingly nervous about the upcoming grain growing season," it said.

"A warm winter can produce a record crop as was the case in 2022, although in that year there was good early moisture in the profile to start the season off, together with a long, soft finish.

"Soil moisture profiles are historically very dry this year and the light falls of rain are either being sucked up like a sponge or are evaporating before it soaks in."

GIWA claims most regions have planted more than 50 per cent of their intended area and will continue to plant dry.

"Without rain in the next two weeks, the northern and eastern regions will pull back on intended plantings and drop paddocks out to fallow," it said.

"This could reduce the planted area in the State by several hundred thousand hectares, and the estimated planted area in this report reflects that outcome.

"However, the planted area estimate could swing the other way by a similar margin if there are decent rains in the next two weeks."

The table of crop area estimates predicts that canola area will be less in 2024 than in 2023 due to the dry conditions, while the lupin area isn't expected to increase and the oat area will increase in the lower rainfall regions which have received rain.

"The wheat and barley swap in area could still vary depending on what happens with rainfall in the next three weeks," GIWA said.

The Geraldton zone is very dry with only the eastern areas receiving rain and the areas usually seeded to canola to be reduced.

"Growers have been dry seeding for several weeks and will continue to do so until they have about 80 per cent of their planned programs in the ground," GIWA said.

"There is about half the intended wheat planting sown to date, mostly on the canola and lupin stubbles and the well managed fallow country.

"As growers push onto the lower potential yielding paddocks, the brakes will come on until it rains."

GIWA said a lot of growers would wait until Saturday, May 25 to make decisions on their planting program.

"The well-known phenomenon of the albatross turning up to make its nest this week has growers excited about the prospect of rain, although time is running out as once May 20 arrives, it is cut-off time for canola, and the end of May is the date most will abandon wheat," it said.

"The main profit driver in the northern regions is emergence date of wheat.

There has been a subtle shift in chasing moisture deep with current wheat varieties, based on the findings of work conducted with long coleoptile wheats in recent years.

Growers have been following the moisture down deeper than previously and obtaining reasonable establishment on very little rainfall.

"This practice change has been driven by the need to get a crop up before the end of May," GIWA said.

"The risk, of course, is how long these crops can hang on with very little moisture under them."

The Kwinana zone has experienced "storm lotto" according to GIWA.

"If you happen to have been under one of the falls of rain, the crops are up and in good shape," it said.

Due to the hit and miss nature of the rain, establishment across paddocks has been patchy.

The region goes from sopping wet around Wongan Hills to completely dry at Miling just a few kilometres down the road.

"The lighter falls of rain in the past two weeks have either germinated crops sown dry, which could be problematic particularly where there is a dry profile under them, or alternatively the moisture has dried out too quickly to have allowed crops to germinate," GIWA said of the Kwinana North Midlands region.

It said the Kwinana South region received less than 10 millimetres of rain, conditions are dry with no subsoil moisture and expects most growers will stick to their planned programs.

"Growers are continuing to dry sow cereals where they know they will not get a split germination," GIWA said.

"The canola area was wound back prior to the recent rainfall event and those that received 20mm or more have swapped back to canola for a few paddocks.

"The end result will be a reduction of around 10pc from planned canola programs.

"For most growers it's the back end of barley programs and onto the wheat for the next few weeks.

"The intended barley area is sitting on about the halfway point and will change over to wheat in the next week."

It is understood the Kwinana North East area is sitting on greater soil moisture reserves than any other region and could still grow profitable crops if there is rain in the next three weeks.

GIWA said the Albany West region had gone from "grim to good in the space of a week".

"The western regions received up to 30mm of rain, tapering down to 15mm in the eastern regions," it said.

"The slow steady nature of the rain followed by some cool cloudy days has seen even the lower rainfall totals soak in to depth in the furrows of the dry sown paddocks.

"Most growers are well into their seeding programs with canola finished.

"The majority of the barley will be in by the end of this week and then, with just the wheat to go, it will be an early finish to seeding for most.

"Until this week, all the crop has gone in without a knockdown, with the boomsprayers cranking up this week."

GIWA said the majority of cereal and canola crops have not required weed spraying in Albany South.

"Growers will now continue with planting the remainder of their cereals dry over the next few weeks with no substantial changes to crop area mix from what was planned," it said.

The Albany East area received reasonable falls and are well set up.

"The rainfall was patchy ranging from 5-30mm so not all growers are set, although most are confident enough to continue with planned programs now," the report said.

"Some paddocks are wet to depth and others are wet just on the surface, with more follow-up rain needed, the majority of the dry sown canola is up and is being monitored closely for bugs."

Finally the report said in the Esperance zone, some growers were two thirds done in their programs, while others were nowhere that point.

"A lot of the crop that has been sown is up in the region, except some very dry pockets in the eastern portions of the zone," GIWA said.

"Even though there are crops up, they are generally patchy.

"There was a lot of soil wetter used and angle sowing this year, which has helped, although the whole area needs a good steady rain to even the crops up."

Ian Foster, Department of Primary Industries and Regional Development's (DPIRD) senior research scientist said the El Nino event in the Pacific Ocean had ended.

"Conditions are expected to remain neutral until at least July," Mr Foster said.

"Indian Ocean Dipole conditions in the tropical Indian Ocean have been positive for the past few weeks, driven by very warm ocean temperatures off east Africa.

"Models are predicting continued development of this event into winter 2024, which would be historically early.

"The Bureau of Meteorology's seasonal outlook indicates an improvement in rainfall chances from June."

Mr Foster said many of the international climate models have a neutral outlook for June to August.

"This comes from a weakening of the previously dominant high-pressure systems south of Australia," he said.

Dr Foster said above normal temperatures would continue through autumn and into winter.

"Chances of unusually high maximum temperatures are about three times as likely for most of southern WA," he said.

"Minimum temperatures are also expected to be much warmer than normal."