AT WA Citrus our goal is to achieve 95 per cent pass rates in maturity testing across WA-grown mandarins and oranges. We are also aiming for 100 per cent pass rates for early-season varieties, which will set up the mandarin market for success in the remainder of the season. As part of this industry program, fruit is randomly selected from wholesale market floors and retail outlets throughout the season.

It is then measured against WA and Australian Citrus Quality standards for juice content and BrimA to ensure it reflects the sought-after citrus zing loved by our consumers.

2023 Season Overview

In the 2023 season, WA mandarins achieved a pass rate of 90 per cent for internal quality down from 93 per cent in 2022; WA-grown oranges had a pass rate of 89 per cent down from 95 per cent in 2023. These results put WA citrus short of the industry goal set in 2021 of 95 per cent pass rates on all WA citrus fruit tested in the market. The 2023 season’s maturity testing results highlight the importance of comprehensive pre-harvest testing on fruit sent to market to ensure not only BrimA, but also juice levels meet customer satisfaction standards. Timely harvest and supply with good management throughout the supply chain ensures the fruit arrives with the consumer at its peak quality.

Focus: Mandarins

Once again early-season Imperial mandarins performed strongly, with 97 per cent of samples passing maturity standards. Clementines, however, had only an 81 per cent pass rate down from 91 per cent in 2023. Failures in Clementines were detected twice in wholesale markets and three times at retail outlets. Samples had juice ranges below the 35 per cent standard from 29.8 per cent to 34.9 per cent.

Late-season mandarin variety Afourers achieved a pass rate of 86 per cent in 2023, improving from 83 per cent in 2022. Afourers were sampled from the market starting in late July. Growers also made use of the maturity testing services, submitting 12 grower samples to TQAS for analysis. However, despite passes later into the season, later than 2022, failures at both wholesale and retail outlets still occurred.

Late July may still be too early to harvest Afourers and also have confidence of a good customer eating experience 100 per cent of the time. When we examine the pre-harvest and post-harvest pass rates we can see that Afourers passed the maturity testing from August onwards (see Afourers Pass Rate, right). Delite, Emporer, Hickson, Gold Nugget, Meo, Mystique, Nectar, Satsuma and Silver Hill mandarin varieties were excellent in 2023 with 100 per cent pass rates across the board.

“ Once again, early-season Imperial mandarins performed strongly, with 97 per cent of samples passing maturity standards ”

2023 Afourers Pass Rate (above)

Pre- and post-harvest pass rates for Afourers throughout the 2023 season. As pass rates from pre-harvest testing increased, the post-harvest pass rate also increased, with no failures from August onwards. These results highlight the importance of waiting until the correct time to harvest and getting fruit tested to ensure it meets the maturity standards when harvesting.

There were several cases in 2023 where a grower did everything right and submitted a preharvest sample which passed. However, when samples were tested from wholesale or retailer, fruit failed due to BrimA. This may have been caused by insufficient pre-harvest sampling. It is important when collecting a pre-harvest sample that you collect fruit that is representative of what will be picked, and the sampling should be spread out as much as possible to ensure reliable results.

“ For every bad taste experience, it will take a consumer six weeks to purchase that fruit again, this could be your fruit or the fruit of other WA growers ”

Focus: Oranges

WA oranges had excellent BrimA in 2023 with high BrimA readings all season and only two failures caused by low BrimA. Navel varieties struggled with juice this year, failing to meet juice standards on 11 occasions, three times when sampled from wholesale floors and nine times when sampled from retailers.

2023 Orange Pass Rate (above)

Post-harvest maturity testing failures in Navel orange varieties throughout the 2023 season.

Low juice content proved to be an issue several times in 2023, in both the Navel and Clementine varieties. The juice content of fruit can be influenced by several factors, such as fertiliser imbalance, water or weather stress, fruit hanging too long on the tree and even soil type and rootstock combinations. Juice also begins to decline in fruit post-harvest. To conserve juice levels, you may benefit from discussions with your supply chain or retailers to ensure fruit is delivered promptly to market and not stored for extended periods. If you know your climate or combination of soil and rootstock is prone to yielding low-juice fruit, it is imperative that you keep a close eye on juice levels and conduct preharvest testing to ensure its juice content is at desired levels before harvest.

It is important to be aware that sending fruit to market that doesn’t meet maturity standards has a wide impact on the whole industry. Fruit is distributed to multiple retailers and can negatively impact a wide range of customers. For every bad taste experience, it will take a consumer six weeks to purchase that fruit again, this could be your fruit or the fruit of other WA growers. By only sending fruit to market that meets maturity testing standards we can guarantee that WA-grown fruit is the freshest and tastiest available and consumers will insist on buying WA-grown citrus.