2022 Macadamia Season Report
To say that the start of the 2022 season has been Annus horribilus is an understatement for any macadamia growers south of the Qld boarder and to a slightly lesser extent those in the SE Qld region. Constant wet weather and flooding rains delayed or stopped harvest. When this is coupled with lower prices it’s no wonder some growers are thinking there are better ways to spend ones time. However, it is not all bad news. The early quality of deliveries from all regions has been better than previous years.
I had this newsletter ready to publish at the end of May, but then the rain stopped so I decided to delay publication so that I could report on the quality of the first consignments after the big wet.
The data presented in this report is based on samples submitted to Cropwatch Independent Laboratory for quality analysis. Cropwatch receives samples from all districts from Rockhampton in the north to Nambucca Heads in the south, so while the data is restricted to Cropwatch intake I believe it is a good representation of the whole industry.
The analysis for the 2022 season is split into regions, Bundaberg, SE Qld (Gympie and Glasshouse Mountains districts) and NSW (Northern Rivers and Nambucca Heads districts). The data has been compared to the average for the same months and districts over the last two seasons.
Kernel recoveries up
The season average for total kernel recovery (TKR) and premium kernel recovery is higher than the previous two seasons for all districts. The TKR for Bundaberg and SE Qld districts is about 1.5% higher than for the same months in 2021. Bundaberg has shown a slight drop in TKR in June compared to June last year, but this is only 0.5% and overall the TKR for the season to date exceeds last year (Fig 1). The TKR for SE Qld continued to improve into June increasing from 36.9% in May to 39.1% in June (Fig 2). TKR for NSW is about 2% higher than the 2021 season. June TKR for NSW remained similar to the May level at 38.2% (Fig 3).
Total Kernel Recovery (TKR)
Figure 1 — Bundaberg TKR (%)
Figure 2 — SE Queensland TKR (%)
Figure 3 — NSW TKR (%)
Premium Kernel (%)
Premium kernel recoveries are also higher across the board for all districts up to May (Figs 4–6). June saw a drop in premium kernel for Bundaberg from 37.2% in May to 35.1% in June (Fig 4). The drop in premium for Bundaberg was due to a slight increase in commercial grade kernel from 1.0% in May to 1.7% in June and a jump in reject kernel from 1.9% to 2.9%. The increase in commercial grade was mainly due to an increase in light discolouration while the rise in rejects was due to increases in internal discolouration and mould (Fig 8).
Premium kernel for SEQ increased from 32.9% in May to 33.8% in June (Fig 5) which followed the increase in TKR. While the % premium increased from June 2022 it is lower than June 2021 because rejects are a full 2% higher than June 2021 (Fig 9).
Surprisingly the premium kernel recovery for NSW held constant at just over 33% in June despite the harvest being delayed due to the wet weather. After the rain stopped harvests and deliveries were further delayed due to many processors and consolidators having reached full capacity and were unable to receive further deliveries. While premium kernel recoveries seem to be unaffected it remains to be seen if the delays in harvest and deliveries have negatively impacted shelf life.
Figure 4 — Bundaberg % Premium
Figure 5 — SE Queensland % Premium
Figure 6 — NSW % Premium
Total Reject Kernel (%)
Reject kernel percentages are generally higher for the Bundaberg district than last year but are lower than the 2020 season. June saw a jump in reject largely due to an increase in internal discolouration and mould following rain in May coupled with daily temperatures in the mid to high 20’s. Several consignments from Bundaberg during June had internal discolouration (brown centres) above 5% and one delivery had levels above 8% which equates to more than 20% of the total consignment! Average mould levels doubled from 0.2% in May to 0.4% in June with frequent consignments above 1% and as high as 5%. Insect damage has been the major cause for reject kernel this year. The season average for insect damage at 1.3% is more than double the 2021 season average of 0.6%.
Reject levels for SE Qld have returned to levels similar to the 2020 season after a low year in 2021. Rejects in May and June 2022 remained constant at 2.7% and 2.8% respectively (Fig 9). Insect damage is the main cause of losses for SE Qld growers followed by internal discolouration.
NSW total rejects are similar to the previous two seasons except for the few early March deliveries (Fig 11). The surprising result with NSW is that, unlike Bundaberg, there hasn’t been an increase in the June reject levels after the extremely wet weather in April and early May and rejects have remained low at 2.2%. The reject analysis shows that insect damage is the main cause for loss followed by internal discolouration (Fig 12).
Figure 7 — Bundaberg % Total Reject
Figure 9 — SEQ % Total Reject
Figure 11 — NSW % Total Reject
Bundaberg — Reject Breakdown
Insect damage has been the major cause for reject kernel this year. The season average for insect damage at 1.3% is more than double the 2021 season average of 0.6%. Internal discolouration and mould increased in June.
South East Queensland — Reject Breakdown
Insect damage and internal discolouration are the main cause for crop loss in SE Qld. Overall rejects in SEQ are lower across all categories than the 2020 season.
New South Wales — Reject Breakdown
Insect damage is the main cause for crop loss in NSW, followed by internal discolouration.
Average figures tell only half the story. Delving a bit deeper into the statistics show that 42% of all quality tests for NSW growers had 0% internal discolouration while many tests revealed more than 3% with a high of 8.1% internal discolouration. The question needs to be answered why nearly half the growers do not have any problem with internal discolouration while a significant proportion have this serious and costly issue. We understand some of the causes for internal discolouration but there is still a lot we do not know.
There is also a difference between the internal discolouration from Bundaberg samples compared to the NSW samples. Some kernel from both districts have the classic brown center that is usually wetter than the outside and has a pungent aroma. Some samples from Bundaberg have a much paler pink to tan colouring and a dry chalky appearance with little or no off smell, and then there is an emerging issue with some NSW kernels that have a wet translucent apperance with a soft texture and a strong sour smell and taste. Clearly there are different types of internal disorders that may have different causes and further research is urgently needed to fully understand this serious industry issue.
Out of the pot and into the fire
When the rain finally stopped in NSW and SE Qld the macadamia industry breathed a sigh of relief. We could finally get back into the orchards and start harvesting. But the relief was short lived. It only took a couple of weeks with farmers going hell for leather to pick up fallen nuts before the delivery system reached capacity and many farmers were being told they can’t make further deliveries for two to three weeks or even longer. Growers without on-farm storage were left with no alternative but to leave the nuts in the orchard.
This situation has been coming for years as the Australian crop has been increasing. The seasonal conditions that hit the southern growing districts this year brought it on much faster and harder than anyone expected.
How did we get here?
If we go back 30 or 40 years it was an industry policy that farmers had enough on-farm storage to hold 50% of their crop. This allowed deliveries to processors to be spread over a longer period and avoided the bottle neck during peak harvest. Then in the early 2000’s research by Mason and Kowitz (2001) clearly showed kernel quality was being compromised in on-farm storage. Nuts stored for longer than two weeks in silos had more discolouration and shorter shelf life. The conclusion to their research was that NIS moisture contents should be reduced to 10 within two weeks of harvest and that silos operated with ambient air couldn’t achieve this with consistent reliability.
The results from this research lead to a change by some processors who encouraged growers not to store NIS on farm, but harvest and deliver to the processor ASAP in order to minimise any post-harvest quality loss. At the same time there was also a shift, especially by growers with smaller orchards, to using contractors and consolidators to harvest, dehusk and store NIS. Prior to this shift virtually every farm had its own harvester, dehusking, sorting belts and storage and so the responsibility for maintaining quality was entirely in the farmers hands.
There is an urgent need for some serious investment in infrastructure across the whole industry. As our crop volumes increase, we will require more storage, more processing capacity or the industry will face this same situation on a regular basis.
Apart from the direct loses to farmers through reduced sound kernel, consignments with higher levels of reject kernel cost more to process and slow processing down. Delays in harvesting will lead to kernel with reduced shelf life and with current technology processors are unable to segregate product with short shelf life. In a world of increasing production quality is paramount. Poor quality in the market runs the risk of alienating consumers which will send wholesale prices into a downward spiral and the whole industry will suffer.
What is the answer?
While on-farm silos would appear to be a quick fix they will be a retrograde step. Australia’s own research demonstrated this 20 years ago. The South African industry, with the benefit of our research, is almost entirely built on “in-shed” storage bins (Bungay System) where the temperature and relative humidity can be controlled. The Bungay system was designed by Dorran Bungay (a process engineer) to maximise kernel quality and to minimise energy consumption. It will be a backward step for the whole Australian industry if there is a rush to install silos on farms. While silos may be a cheaper convenient option, I would urge anyone considering installing on-farm storage to look closely the true costs of second grade systems, including the lost kernel quality and costs of operation. In a good year they may be OK but at a price reduction of 10-20cents for every 1% increase in reject kernel it would not take many seasons to recoup the additional expense of a Bungay style system. Those who already have silos should refer to the AMS fact sheet “Silo modifications to Improve Efficiency and Macadamia kernel Quality” (2010).
The best option is still for processors to take delivery and begin the curing process ASAP, after all they have the expertise and trained personnel to ensure that the best quality is preserved. However, failing this it will be in the farmers own interest to ensure that they have a sound strategy and infrastructure to prevent post-harvest losses from delayed harvests and or delayed delivery.
Dorran Bungay has just released his new book, Macadamias. An Overview and Guide to Preservation and Principles and Engineering Practice. It deals extensively with post-harvest care as well as engineering designs for curing (drying) and processing.
Reference
Mason R and Kowitz T, (2001) Drying Macadamia Nut-In-Shell On-Farm, HRDC Project Number MC97011
Jones K, Bungay D, O’Hare P, Quinlan K, Le Lagadec D, McConchie C (2010) Silo modifications to Improve Efficiency and Macadamia kernel Quality”, AMS Fact Sheet No. 3
NOTE: The views expressed in this newsletter are entirely my own and may not reflect the opinions of others in the industry.
Closing Remarks
Cropwatch has expertise in post-harvest quality management and is happy to advise growers. Please do not hesitate to contact us if we can assist in any way.
Regards,
Kim Jones
Senior Consultant, Cropwatch Independent Laboratories
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