The 2024 Grain Season – Season Saving Rain
Several rainfall events over the last two weeks in Western Australia have ensured crops that were sown dry will germinate and crop that was up will now have at least a chance of returning reasonable grain yields. Various areas of the state were still very dry at the start of June and the majority of crops particularly in the central and north of the state had not germinated or fully germinated. The rain events initially missed the extremely dry northern and central eastern grain growing regions and the majority of the Esperance port zone. Although as more rain fronts came through, those areas all received good soaking rains. The only area that has continued to miss out on rain is the southern coastal higher rainfall zones.
Due to the unseasonally warm soil temperatures, crops are bouncing out of the ground and making up time in growth stage. The result is we are now on track for at least an average year rather than a well below average year as was the case just a few days ago.
The rains in the last five days, in particular, have completely turned around the chances of growers reaching average grain yields in the northern portions of the Geraldton port zone where there was no crop up, and the large areas of the low rainfall East Kwinana port zone, north of the Great Eastern Highway where very little crop had germinated. Crops in the remainder of the state that had germinated were mostly patchy, with germination closely related to soil types, with the heavier soils generally poor. These crops have already started to even up from the recent rain and where crops had previously come through with an even germination, they are in good shape now.
The estimated crop area has increased a little from last month as growers continued to sow paddocks as the forecast for rain began to look more promising. The increase in area has mostly been in wheat and resulted from some resowing of poorly germinated canola paddocks and an extra paddock or two swapped from fallow and pasture.
With temperatures forecast to be warmer than average this winter due to abnormally high sea surface temperatures in the Indian Ocean, there is the potential for cereal crops to make up enough ground to yield well even after such a late break to the season. But to achieve this, the rain will need to keep falling as soil moisture profiles are still very dry in most places and the finish will need to be mild.
It is a different story for the break crops with most canola crops in the medium and low rainfall regions down on plant density and germinating too late to reach profitable yields. Lupins are in the same boat and many north of the Great Eastern Highway are already destined to be brown manured.
Seasonal Outlook
Ian Foster, Department of Primary Industries and Regional Development
Climate summary
Seasonal climate June 2024
Rainfall
After a prolonged period of very dry and hot conditions, May saw welcome rain, mostly in the southern parts. A series of weather systems have continued to see rain persist into early June. Tropical interaction has brought very good rainfall for the northern cropping area, however, the eastern South Coast is still waiting for significant rain. (See Figure 1.) Soil moisture storage remains low in these areas.
Forecast
Climate conditions in the Indian and Pacific Oceans are neutral. Chances are rising for development of a La Nina event, but this will have little impact on Australian rainfall at this time of year. Several models continue to predict a positive Indian Ocean Dipole over winter, although predictive skill is poor.
The Bureau of Meteorology’s seasonal outlook for July to September has neutral rainfall chances for much of the cropping area. (See Figure 2.) The outlook has a slight preference for wetter conditions for the northern cropping region and drier conditions for the eastern South Coast. Many of the international climate models have a neutral outlook for this period. This is a better outlook than the same time in 2023.
Figure 1: Rainfall totals for early June 2024. Source: Bureau of Meteorology (2024)
Figure 2: Rainfall outlook for July to September 2024. Source: Bureau of Meteorology (2024)
Temperature
Seasonal temperatures over summer and into autumn have been very much above normal. Soil temperatures remain warm, though have cooled with recent rain.
Predictions of above normal temperatures continue through into winter. Chances of unusually high maximum temperatures are about three times as likely for most of southern WA. Minimum temperatures are also expected to be much warmer than normal.
Additional information is available from:
BoM: Decile rainfall for January to May 2024
BoM: Rainfall outlook for the next week
Geraldton Zone
The Geraldton port zone has received more rain in the last week than for the whole of 2023. Most of the region now has a full profile of moisture from the slow, gentle rain that fell last weekend, and cereal crops have a chance of returning reasonable grain yields if the season goes their way from now on.
Canola crops are very thin and down on plant density with about 20 per cent of paddocks needing resowing to some extent. The canola crop area is estimated to be about half that of 2023, and most has below average grain yield potential due to the later than ideal emergence.
Around 5-10 per cent of cereal paddocks on the heavier soils needed resowing prior to the rain, where they emerged and died. The lighter soils that were sown dry to cereals have emerged beautifully following the rain ten days ago and were boosted by the soaking rains last weekend. The crops that were sown deep chasing moisture in May are looking exceptional.
With a full profile of moisture on the deep lighter soils and cereal crops up and away and growing quickly under the warm conditions, the region will not need a lot more rain to get an average season. But rain will still be needed in August and September to finish off the crops, and the season will now be determined by conditions in spring.
Whilst growers are very positive with their cereal programs, the same cannot be said for the break crops. Both canola and lupins will not be profitable this year. The crops are simply too late and poorly established to return reasonable grain yields. Most growers needed to resow portions of canola paddocks and even though most won’t be profitable due to low plant density and being well behind where they should be for this time of the year, growers will see them out to try and return some of the costs of seed and other input costs. The same cannot be said for many lupin paddocks and many are earmarked for brown manuring already.
The cereal area is up from 2023 due to the large area that was fallowed in 2023 now sown to crop, coupled with a swing out of canola to cereal due to the late break of season, and some paddocks that were sown to canola ending up being resown to wheat.
Kwinana Zone
Kwinana North Midlands
The last 10 days have been brilliant right across the region with most areas receiving 30-40mm of rain. The western areas were well over this with up to 70mm in places, and the eastern areas received crop saving falls of up to 30mm.
The rainfall was very effective with slow soaking events which have put the whole region back on track for a reasonable year. While the rain has come a little late for many of the canola and lupin crops, the wheat and barley crops have jumped and are growing quickly at rates more typically of May. The cereals will make up lost time in these warm growing conditions and are on track now for grain yields closer to ten-year averages, rather than more recent very high averages.
The majority of the barley sown in the region is now Maximus®, rather than the longer season varieties of recent years, which will still yield ok in a short growing season. Growers swapped to the shorter season wheats as well when it was obvious the season break was holding off. These can also yield well even after a late start.
Kwinana South
Germinated crops were holding on during the dry spell in May, and those that had not germinated are now up and away. Growth rates have been quick in the last two weeks and most crops have made up ground and are well set up going into winter.
The region is quite patchy with some very good pockets interspersed with some areas that have just germinated in the last two weeks. Areas of the region bordering on the Kwinana East zone were brown up until the last week, whilst areas around Corrigin/Bruce Rock, Quairading and north to Dowerin are quite green now. The higher rainfall areas to the north-west of Narrogin have only received germinating rains in the last two weeks, while the Narrogin area is now green from the nice falls of rain a month ago.
Overall, the region is in good shape at this stage of the season and most crops are on target for at least average grain yields if the season holds from now on.
Kwinana North East
Up until recently, large tracts of land north and east of the Great Eastern Highway had received no rain for seven weeks and was completely brown at the start of June. The whole area was looking down the barrel of a very poor year, however, crops are now coming through and there is a light green tinge with dry sown crops jumping out of the ground in the last few days.
Most of these areas did receive summer rain and have small reserves of moisture to give them a buffer. Crops emerging now are late for the region, and while they will make up a bit of time from the warm soil temperatures, they currently have below average grain yield potential.
There is a reasonable area of canola sown in these low rainfall regions again this year following the summer rains. Canola crops are either very patchy or haven’t emerged with enough numbers to make a crop in a lot of cases. Some that had no pre-emergent herbicide applied have be resown to wheat and others that did emerge are going to struggle to yield profitable returns for growers.
The very warm temperatures in autumn dried out the soil profile too quickly for crops to germinate following sowing, and the small rainfall events that followed which would normally keep crops alive germinated the remaining seed, which then mostly died, killing off any hope of a profitable crop. This was also the case over large areas further north. This will have a significant impact and put a ceiling on the state’s canola tonnage at harvest time.
Albany Zone
Albany West
Month-to-date rainfall totals have been around 50mm or above for all areas west of the Albany Highway and whilst totals drop off east of here, there has been enough to keep the early germinated crops ticking along and has given the later crops the boost they needed. The exception to this is the heavier soils east of the Albany Highway where crops are struggling, particularly where rainfall totals from the recent rainfall events were in the 10-20mm range.
Most of the canola germinated following rain at the end of April and early May, but then went through a dry spell in May, which put many crops under pressure and the brakes on growth. The recent rain has brought them to life and they now have good grain yield potential.
All the cereals are now up and have taken off in the last 10 days. Most have very good grain yield potential as they generally have enough moisture now to get them through the predicted next few weeks of dry weather. This could play into their hands as getting the jump on potential waterlogging before the winter sets in could mean some nice yields are in store if the spring conditions are favourable.
Nitrogen top-ups are going on following the recent rain and most growers are sticking to planned regimes at this stage of the season.
Albany South
Rainfall south of the Stirling’s has been down on average and is well below average closer to the coast. The whole south coast across to the Esperance port zone has not received typical winter frontal rains yet and is very dry for this time of the year. These areas do have time to recover and in fact it could be a benefit once the rains come as it may allow crops to handle the inevitable waterlogging experienced in these areas.
Red Legged Earth Mite have hatched “en masse” following the rain and slightly cooler temperatures in all the southern zones, and along with all the usual winter pests, slugs are now becoming active.
Albany East (Lakes Region)
Since early May, rainfall events in this region have been patchy with most growers seeing less than 10mm for the month. This has resulted in stressed crops which have fallen vulnerable to bug damage, predominately bryiobia mite with some balaustium mite.
Rainfall in June in the region has been at the lighter end of the scale, with most centres receiving less than 20mm of rain over several events. Whilst useful, the lack of subsoil moisture is a concern as crops had mostly germinated and were becoming quite stressed. Despite being light, the rainfall in the last few days will help keep crops moving along.
There is a bit of concern for large areas of the zone with minimal stored moisture and patchy germinations, which is more prevalent in heavier soil types where establishment struggled in dry conditions.
In those areas which have received up to 25mm since the last Crop Report, crops are growing well.
Seeding has wrapped up for the region with the majority of the crop now out of the ground. Most canola paddocks have received all planned weed control sprays. Some areas have seen Diamondback Moth in early March sown canola, however this is not widespread.
Ryegrass is just starting to emerge with the colder temperatures and rain events, and early herbicide applications are going out now to control weeds in the cereal crops.
Esperance Zone
Crop growth in the region is “all over the shop”, with crops generally in better shape in the western areas than the eastern areas of the zone.
The region went through a very dry period in May and while the majority of crops had emerged, many were stressed and not actively growing. Crops emerging during this period were taking forever to come through. The rain in recent days has again been mixed for the region, with the central corridor from Salmon Gums to Esperance receiving most of the falls of rain over 15mm. To the west and east, rainfall totals dropped off to around 10mm or less, with the trend along the coast to the west being totals of less than 10mm.
Due to a lack of good soaking rain so far this year the non-wetting sands have struggled, with many crops having staggered emergence. It is quite noticeable where soil wetters or angle sowing have been employed and on ameliorated country, the crop establishment is improved resulting in a more even germination. These practices seemed to have paid off this year.
Cereal crops have generally established better than canola crops, and many canola crops are down on plant numbers. The cereals were sown deeper and those that have had rain on top of them are quite even and have reasonable grain yield potential. The whole zone has very low soil moisture reserves going into winter and crops will need the rain to keep coming to bring their grain yield potential up closer to ten-year averages.