The traditional winter price drop for avocados has failed to materialise this year, says Avocados Australia Chair Jim Kochi.
“As a North Queensland grower supplying the market at this time of year, I know from experience that through winter, prices tend to drop because consumers go a bit ‘off the bite’ for avocados after the first cold snap,” he said.
“That hasn’t happened this year with and I’ve heard of growers receiving up to $50 a tray.”
Mr Kochi said as well at a tighter supply in most regions currently, he put the change down to consumers extending their uses of avocado, and having confidence in using the fruit in a variety of dishes and meals.
“There’s never a shortage of avocados in winter, the change this season has been that returns to growers have remained quite high, with stock moving through stores quickly,” he said.
“I would say the consumer is more committed to using avocado now, regardless of the weather,” Mr Kochi said.
He said another important factor was improved retail displays, with single-layer fruit displays reducing the potential for bruising.
“I’ve also seen many displays that have ‘ready to eat today’ and ‘eat tomorrow’ to help consumers choose the best fruit for them.”
However, Mr Kochi warned all the good work of industry to increase year-round consumption to match year-round availability could easily be undone.
“We as growers need to make sure we keep quality high because we have to meet consumer expectations; without them we don’t have an industry,” Mr Kochi said.
“As long as we’re vigilant about quality, the consumers are happy to take our product, regardless of the weather.”
This article was produced for the Guacamole, 18 August 2017.
See the latest marketing activity that’s helping Aussie consumers connect with (and eat!) Australian avocados. The industry’s marketing is managed by Hort Innovation and funded by the avocado marketing levy. Hort Innovation develops consumer-focused promotions using a variety of mediums including social media platforms such asFacebook, Twitter, Pinterest, Instagramand YouTube as well as targeted partnerships with consumer related publications and platforms.
The Betoota Advocate
As part of Hort Innovation’s levy-funded marketing activity for the industry, Australian Avocados has recently worked with popular satirical news website The Betoota Advocate (www.betootaadvocate.com) to publish two articles about avocados. The partnership was decided on to leverage the publication’s voice and social influence for avocados, and to lighten the conversation around consumer gripes.
Started in 2014, and now the most popular satirical news site in Australia, The Betoota Advocate’s growing readership base is largely driven via its social page on Facebook, where it boasts in excess of 330,000 followers. While based in inner Sydney, the site takes its name from the deserted regional Queensland town of Betoota, with its articles putting a comedic spin on current news topics and broader social observations.
Article 1 – a witty response to housing affordability
The first Australian Avocados article, published in early July, was a timely and witty response to the recent rhetoric around avocados and housing affordability. You can view the article, First Home Buyer Hospitalised With Avocado Deficiency, here.
Article 2 – tackling purchasing nervousness
The second article was to address one of the key purchase barriers of avocados identified by consumer research: nervousness about buying an avocado that is bruised or otherwise blemished inside. The goal was to educate consumers about correctly handling avocado, in a humorous way that would not put people offside. The resulting article, published in late July, was titled Husband Blames Farmers For Bruised Avocados At The Bottom Of His 20kg Grocery Run.
Campaign success
The Betoota Advocate campaign was a great success, with more than 1.8 million views of the avocado articles. Just over one million of these views were on The Betoota Advocate’s Facebook page, with 12,500 people clicking through to read the full articles on the publication’s website.
Total views of the articles on the website were close to 33,900, with the average time spent on the website was 1 minute and 15 seconds. This time shows that the people who went to the web page took the time to read the articles in their entirety.
Readers loved the avocado articles, with the overwhelming majority of comments on social media being positive. People were both amused by and supportive of the content, getting on board and extending upon both jokes in many instances. Overall, the campaign was an incredibly successful and cost-effective exercise in driving social brand awareness, based on trends relevant to our target audience.
This update was provided by Hort Innovation for Guacamole 18 August 2017.
This article appears in the Winter 2017 edition of Talking Avocados (Volume 28 No 2).
Ripe & ready to eat in Singapore
By Jenny Margetts, P2P Business Solutions
In recent week Australian exporters, Avocados Australia and the Department of Agriculture and Fisheries Queensland have been working together to support ‘ripe & ready to eat’ export trials in the Singapore market.
“We have a great advantage in Singapore in that our fruit is the freshest and we want Singaporeans to be able to access ‘ripe & ready to eat’ Australian avocados,” Avocados Australia CEO John Tyas said. “We know from research here in Australia and in other countries that offering a ‘ripe’ selection of fruit will increase overall sales in the category.”
Antony Allen, CEO of The Avolution, who was supporting the trials in Singapore, said one of the challenges was to have consistently ‘ripe’ product in the best possible condition for the consumer.
“This means it’s important that everyone along the supply chain plays their role. In recent weeks we have been working with our importer to deliver a ‘ripe & ready to eat’ program through one of the supermarket chains in Singapore,” Mr Allen said.
The project team is delivering training to staff members tailored to meet the needs of the supply chain businesses and at the same time helping educate consumers in Singapore.
“Primarily, Singaporean consumers seem interested to know about how they can use avocados and how to tell if an avocado is ripe, so we are using point-of-sale leaflets to educate consumers on how to choose a ripe avocado, ways they can use them and why they should be buying Australian avocados,” Mr Tyas said. “They know that avocados are healthy for you and often use avocados in smoothies with milk or coconut milk and palm sugar.”
In recent store demonstrations in Singapore, customers were offered ripe cubed avocado dipped in cocoa powder and cayenne pepper – a combination of sweet and savoury, which most customers seemed to enjoy. Changing culinary trends in Singapore are also resulting ‘ripe & ready to eat’ in Singapore in avocados being used in other ways, such as in salads and guacamole.
The Mahota chef and product demonstrator for Australian avocados at the Prime Supermarkets’ flagship Mahota Commune store.
“It is also often said that Singaporeans prefer to buy their avocados unripened and wait for them to ripen at home,” Mr Allen said. “Our anecdotal evidence, from the work that has been undertaken in recent weeks, is that consumers may be more interested in purchasing ‘ripe’ fruit than the market expects. As part of the process, sales data and feedback from the supply chain partners in Singapore is being analysed to see how the figures stack up.”
The range of training materials Avocados Australia and DAF Queensland have developed for supply chain parties is being tested and modified to suit the market. It builds on previous industry work and aims to improve ripening and handling skills along the supply chain to the retail store.
Although the focus is on retail, the training being undertaken will also benefit food service supply chains that Australia services in Singapore.
On the Australian side, Avocados Australia is looking to support growers and exporters in the adoption of improved handling practices so that the fruit being offered in export markets is of the highest quality.
“We know that with the increasing supply of avocados in the coming years that the development of premium export markets will be very important for our industry,” Mr Tyas said. “We are heartened to see that growers are actively asking for information about how they can support and participate in export supply chains. During the next year, we plan to work with our exporters and growers to help the whole industry gain a better understanding of export requirements and have fruit that is export-ready.”
Acknowledgement
These market development activities are being undertaken as part of a project being funded by the Australian Government’s Package Assisting Small Exporters Program, the Avocado Export Company, Sunfresh and The Avolution.
This article appears in the Winter 2017 edition of Talking Avocados (Volume 28 No 2).
Can we increase avocado production via pollination?
By Bryony Willcox, University of New England
In Australia, crops that benefit from insect pollinators have an estimated value of $4.3 million.
The pollinators that visit avocado flowers include managed honey bees, other wild bees, flies, wasps, beetles and butterflies. As pollination services delivered by insect pollinators are a key driver of yield and quality variability within these horticultural systems, increased knowledge about how we might go about reducing this variability through pollination is an important step forward.
The potential use of remote sensing to better understand this yield variability is being evaluated in a current national research project Multi-scale monitoring tools for managing Australian Tree Crops – Industry meets innovation (ST15016), funded by the Federal Government Rural Research and Development for Profit Scheme, and supported by Hort Innovation. One goal of this project is to map yield parameters and tree vigour across avocado orchards, and to better understand the extent to which these two aspects relate to pollination services.
The first interesting finding is that pollinator communities can differ from orchard to orchard within a region. For example, in the last flowering season (2016), honey bees were the most abundant flower visitor across seven Hass orchard blocks surrounding Bundaberg. Apart from honeybees, it was found that wild bees, beetles and flies also visit flowers and that individual avocado blocks differed in the identity of the most abundant pollinator group present (Figure 1).
Figure 1. Abundance of insect pollinator groups observed at two different orchard blocks in the Bundaberg region, 2016
We then looked at how tree vigour (combination of tree size and health), interacts with pollination services provided by insects. In this project, tree vigour is determined by an NDVI (normalised difference vegetation index) image derived from Worldview-3 satellite images (Figure 2).
Figure 2. An example of a satellite-derived NDVI image being used to determine high, medium and low vigour canopy growth across an orchard block. The yellow pins indicate the location of individual trees. These either received hand pollination treatment or were left as open controls, across varying tree vigour regions. The image has been overlayed onto Google Earth.
Looking at these interactions a hand pollination trial, replicated across five Hass orchard blocks in the Bundaberg area, began last year. The trial involves hand pollinating trees that represent a range of tree vigour classes with outcross pollen (Shepard variety) in addition to the open pollination services they already receive. A second group of trees across the vigour range did not receive the additional hand pollination, representing open pollination, and were retained as controls. At harvest, fruit number and weight of fruit were measured for each of the experimental trees.The second interesting finding is that trees with a low and medium vigour rating can produce increased yields (both fruit number per tree and
The second interesting finding is that trees with a low and medium vigour rating can produce increased yields (both fruit number per tree and total weight of fruit per tree) after receiving additional hand pollination (Figures 3 and 4).
Figure 3. Mean fruit number per tree across five Hass experimental blocks in Bundaberg, Queensland. Bars represent standard error of means. *represents significant difference between means of treatment and control groups
Figure 4. Mean total fruit weight per tree across five Hass experimental blocks in Bundaberg, Queensland. Bars represent standard error of means.
This suggests the medium to low vigour trees might be pollen limited. Interestingly, high vigour trees suffered reduced yields following hand pollination. We will also be comparing fruit quality measures between hand-pollinated and open control trees to better understand these results.
These experiments will be repeated in the upcoming 2018 harvest year to determine if the same trend is repeated, or potentially to identify if the smaller trees suffer a yield decline as a result of the higher yields they achieved during the 2017 harvest season. The findings may allow growers to quickly evaluate their orchards to make predictions of pollinator distribution and yields in their specific orchards.
Acknowledgement Bryony Willcox is a PhD student at the University of New England, Armidale, collaborating with Associate Professor Andrew Robson, Dr Romina Rader and Dr Brad Howlett. The PhD project is being conducted as part of the Federal Government Rural Research and Development for Profit Scheme, supported by Hort Innovation. We would like to thank the growers in Bundaberg who allowed us access to their orchards including Simpson Farms, Chad Simpson, Tom Redfern (Donovan Family Investments) and AustChilli Farms.
See the latest marketing activity that’s helping Aussie consumers connect with (and eat!) Australian avocados. The industry’s marketing is managed by Hort Innovation and funded by the avocado marketing levy. Hort Innovation develops consumer-focused promotions using a variety of mediums including social media platforms such asFacebook, Twitter, Pinterest, Instagramand YouTube as well as targeted partnerships with consumer related publications and platforms.
Australian Avocados Facebook
In the month of June, Australian Avocados had five posts to Facebook. Managed by Hort Innovation on behalf of the industry, the Australian Avocados Facebook page (www.facebook.com/AustralianAvocados/) is an important component of the industry’s marketing program.
The top performer for June was a ‘Breakfast Hack’ video, which you can watch at www.bit.ly/2ux8uWj. Showing a simple yet creative way to use avocados in a twist on the favourite ‘egg in the basket’ breakfast (an egg cooked in the middle of bread), at the time of writing the post had reached nearly 900,000 people and attracted an impressive 6,244 comments and close to 1,000 shares. The latter means that nearly 1,000 people loved the content so much that they shared it with their friends on Facebook.
In total, the five pieces of Facebook content for the month of June reached over 3,075,000 consumers. This number includes people who may have seen the content more than once.
This update was provided by Hort Innovation for Guacamole 4 August 2017.
This week is National Farm Safety Week, and according to Safe Work Australia statistics, there’s still a lot of work to be done to make the agriculture, forestry and fishing industries safer.
As at 20 July, 2017, 21 people in the agriculture, forestry and fishing industries have lost their lives at work, and 41 in total died during 2016 (Figure 1). The latest Safe Work Australia data is based on initial media reports and is a preliminary estimate only but so far, it reflects the final figures of 2003-2015 where the agricultural industries had the second highest level of fatalities nationally.
As 2017 National Farm Safety Week got underway, Assistant Minister to the Deputy Prime Minister, Luke Hartsuyker, encouraged farmers and rural workers to keep their safety, health and well-being front and centre all year round.
“Agriculture is the biggest employer in our rural and regional communities, so farm safety should be a priority for everyone in the sector,” Mr Hartsuyker said.
“While the government will continue to work closely with industry and peak work safe bodies to address farm safety, it is everybody’s responsibility to ensure farm health and safety is treated as a priority and that proactive steps are taken to recognise warning signs and mitigate any risks.
“One of 2017 National Farm Safety Week’s main focuses was quad and vehicle safety, given tractors, other machinery and quad bikes are the leading causes of deaths on farms.”
According to Safe Work Australia’s Work-related traumatic injury fatalities, Australia 2015, between 2003 and 2015, there were 744 agricultural fatalities in total, or 23 percent of all worker fatalities. Of those, 247 died in a vehicle collision or rollover. In 2015 alone, there were 52 fatalities (Figure 2).
According to the report, when considered on fatality rate (fatalities per 100,000 workers), agriculture, forestry and fishing have almost consistently had the highest rate since 2003, with an overall rate of 17 deaths per 100,000.
The report also notes that agriculture is one of the few priority industries (agriculture, transport and construction) where fatality rates have not decreased. Instead, they have remained close to 15 fatalities/100,000 workers for much of 2003-2015.
Narrowing by industry and how (Table 1), for the fruit and tree nut growing industry, the rollover of non-road vehicles produced the highest number of fatalities between 2003 and 2015, followed by being trapped between stationary and moving objects (six) and then vehicle collisions and being hit by moving objects (five fatalities each).
According to the 2013 report, between 2004/2005 and 2010/2011, the number of workers in the under 25, 35-44 and 45-54 age group fell while those in the 65+ age group grew.
The analysis profiles the 356 fatalities that occurred on farms in the eight years to 2010-11 and found males accounted for 92 percent of the fatalities, and there was an increasing proportion of worker fatalities with age.
“Workers aged 65 years and over accounted for 30 percent of all fatalities on farms in the eight years. This is nearly three times the proportion this age group represents of all worker fatalities,” the report said.
“For the 55–64 years age group similar proportions were recorded for those working on farms and for all workers, while for all younger age groups the proportion of deaths occurring on farms was lower than for all workers. These data show that there is a greater risk of death for older workers on farms than for the wider working population.”
Now in its 19th year, this year’s National Farm Safety Week took place from 17-21 July, with a theme of ‘creating a resilient, safe and healthy ag community’. National Farm Safety Week is an initiative of FarmSafe Australia, with the aim of raising awareness and reducing deaths and injuries associated with health and safety risks on farms.
See the latest marketing activity that’s helping Aussie consumers connect with (and eat!) Australian avocados. The industry’s marketing is managed by Hort Innovation and funded by the avocado marketing levy. Hort Innovation develops consumer-focused promotions using a variety of mediums including social media platforms such asFacebook, Twitter, Pinterest, Instagramand YouTube as well as targeted partnerships with consumer related publications and platforms.
Australian Avocados Facebook
Managed by Hort Innovation on behalf of the industry, the Australian Avocados Facebook page (www.facebook.com/AustralianAvocados/) is an important component of the industry’s marketing program. The page is liked by more than 185,000 consumers (whose ‘likes’, comments and shares on the page reach even further to their own digital social circles), and has an ‘always on’ approach that keeps Aussie avocados top of mind for consumers year round.
The page allows Australian Avocados messaging and inspiration to get to audiences in a quick, fun and personal manner – and social media has never been more relevant. In 2016, 69 percent of internet users had at least one social media profile, with a quarter of these checking their profiles more than five times a day, and the average Facebook user spending 12.5 hours per week on the site. In particular, Facebook activity helps reach the younger end of our target audience, who may not be consuming as much ‘traditional media’ (such as newspapers and live television) as older generations. From the demographic splits seen below, 36 percent of women who saw Australian Avocado Facebook content during the month of June sat in the 25-34 age group.
With the 2016 Sensis Social Media Report showing 52 percent of consumers trusting brands more on social media if the brands interact with customers in a positive way, it’s important to ensure that the Australian Avocados page responds to the people who have taken the time to comment on its content. Each day, comments on any posts are responded to, opening up valuable two-way communication with Australian Avocado fans.
This update was provided by Hort Innovation for Guacamole 21 July 2017.
By Melinda Perkins, Muhammad Mazhar, Daryl Joyce, Noel Ainsworth, Lindy Coates and Peter Hofman
Avocados are prone to flesh bruising, especially once they reach retail shelves (Figure 1). This issue is a major concern to the Australian avocado industry, with flesh bruising being responsible for around half of all avocado internal defects detected at the retail level1. A problem for shoppers is that they can’t tell if a fruit is bruised internally until they cut it open at home. The end result in many cases is consumer disappointment and a reluctance to purchase avocados in the future2.
What is it that makes avocados susceptible to bruising and can anything be done to make them more resilient? Mechanisms involved in avocado flesh bruising and factors that govern them are discussed here with a view to reducing bruising.
Figure 1. Flesh bruising in Hass avocado fruit at the retail level is a major quality issue.
What is bruising?
Physical injury of avocado fruit tissues occurs in response to applied mechanical force. Damage that leads to bruise expression is caused by impact (e.g. dropping), compression (e.g. squeezing) and/or vibration (e.g. transport) injuries. The walls of cells comprising fruit tissue are elastic to a limited degree. As such, they can absorb some of the physical shock without permanent injury being caused. However, when cells experience stress beyond their elastic limit, the cell walls fail and permanent damage occurs. In this circumstance, cell contents previously separated within compartments in the cell will mix together as the cells rupture. This brings phenolic compounds into contact with the enzyme polyphenoloxidase (PPO), which triggers enzymatic browning resulting in polymerised phenolics. These are brown in colour and are responsible for the typical dark discoloration recognised visually as a bruise.
How is bruising measured?
Flesh bruising in fruit has been described and measured in various ways3. Bruise incidence can be defined as the number of bruised fruit in a given sample (e.g. tray) of fruit. It can be expressed as a percentage of the total number of fruit affected within the sample. Alternatively, it can be measured and expressed as the number of bruises on any individual fruit. Bruise incidence data do not indicate the degree to which fruit are bruised. Bruise severity, on the other hand, indicates the size of a bruise. It is generally quantified as either the area or the volume of the affected flesh in individual fruit. The value may also be converted to a percentage of the total fruit flesh area or volume. The avocado industry recognises the importance of both bruise incidence and severity, and tracks the percentage of fruit at retail with more than 10 percent affected flesh area1 (the level generally considered to be unacceptable to consumers2). Bruise intensity is a measure of the relative darkness of a bruise. It can be scored visually (e.g. light brown to black) or measured with a colour meter. The latter involves recording three colour coordinate values (e.g. L, a, b) that pinpoint a particular colour in a three-dimensional colour space of all possible colours4. Bruise susceptibility is the relative degree to which a fruit bruises when given a specific damaging pressure. It is expressed as the amount of flesh showing damage per unit of absorbed impact or compression energy.
What affects bruise susceptibility?
Anecdotal and experimental evidence suggest that the susceptibility of avocados to bruising is related to fruit firmness, dry matter content, flesh temperature, and time in the supply chain.
Firmness is an indicator of cell wall strength in fruit tissue and a way to determine the ripeness of avocado fruit. Firmness decreases during ripening and has been characterised into the stages of hard, rubbery, sprung, softening, firm-ripe, soft-ripe, overripe, and very overripe5. Bruise susceptibility increases as firmness decreases. For example, injury due to a “very slight” thumb compression of 5 Newtons produced twice as much bruising (in terms of bruise area) in soft-ripe than firm-ripe Hass avocados (unpublished data; Figure 2). For impact injury, the drop height at which Hass avocados began exhibiting bruising was 5cm for sprung fruit and 2.5cm for firm-ripe fruit6. Mathematical modelling for Collison avocados suggested that the critical drop height for bruising was approximately 3cm in fruit that the authors referred to as “ripe”7. In contrast, hard fruit are resistant to bruising. No permanent bruising was recorded for hard green mature Hass avocados after impact from a drop height of 100cm. Initially damaged tissue in green mature fruit was apparently able to recover over time8.
Figure 2. Bruising in Hass avocados subjected to a “very slight” thumb compression of 5 Newtons at different stages of ripeness.
Dry matter content tends to increase over the harvest season and is a reliable measure of avocado maturity. Fruit with higher dry matter were less susceptible to bruising in a study that subjected firm-ripe Hass avocados to a 50cm drop height8. Bruise volume progressively decreased as dry matter increased from 22 to 33 percent.
Relatively high fruit dry matter can offer consumers a better eating experience2. On the other hand, waiting to harvest unusually high dry matter avocados might lead to a less desirable eating experience. For example, a slight decline in consumers’ intentions to purchase avocados was observed when dry matter exceeded 40 percent2. Furthermore, a very late harvest may deplete carbohydrate reserves in the tree and increase the risk of biennial bearing9. Delaying harvest to ‘meet and beat’ the minimum recommended dry matter level for harvest (i.e. 23 percent+ for Hass) is likely to be a good compromise towards reduced bruise susceptibility.
The temperature of the fruit following an impact is a potentially important factor in lessening avocado flesh bruising. Hass avocados held at 5°C for 48 hours after being impacted did not show bruising8. In contrast, holding impacted fruit at 15 or 25°C for the same period resulted in 90 and 95percent bruise incidence, respectively. Moreover, bruise intensity was higher (i.e. darker) in fruit held at 25°C than at 15°C. The data suggested that flesh temperature during the first eight hours after impact is critical in determining visible bruising. Relatively greater PPO activity was considered to be the likely cause for greater bruise incidence observed at higher temperatures. Note, however, that chilling injury may occur in Hass avocados at 3°C or lower. Also, refrigeration of fruit at retail level may have cost and other marketing considerations.
Prolonged time in the system has been shown to increase the susceptibility of Hass avocados to bruising. When subjected to impact at the firm ripe stage, fruit stored at 5°C for one to five weeks prior to ripening tend to exhibit greater bruise volumes than un-stored control fruit8. A trend of increasing bruise volume was observed with increasing cold storage duration.
Any other factors?
Although not specifically researched to date, other factors are likely to affect bruising susceptibility by influencing the physical properties of cell walls and/or enzymatic browning processes.
Pre-harvest water stress has, for example, been found to promote PPO activity in avocado fruit10. Therefore, it might be reasonable to expect bruise expression to be greater in water deficit stress affected fruit. However, investigation is required to establish if this is the case.
Cultivar (i.e. genotype) is known to dictate the enzymatic browning potential of avocado fruit. For instance, the rate of cut flesh browning, as well as flesh total phenolic content and PPO activity, are greater in Fuerte than in Lerman11,12. For cultivars common in Australia, the peel of Hass avocados contains greater concentrations and diversity of phenolic compounds than does Shepard avocado peel13. The concentration of epicatechin, a known PPO substrate, exhibited a dramatic decrease in Hass avocados during a harvest season14. This trend may at least partly explain the decreasing bruise volumes observed with increasing dry matter over time as noted above.
Choice of rootstock cultivar has been shown to affect calcium (Ca) accumulation in avocado fruit. Ca is important for cell wall strength and membrane stability. Compared to fruit containing low Ca concentrations, Hass avocados with relatively high flesh concentrations at harvest show delayed ripening15,16, greater firmness after storage17, lower incidence and severity of body rots15,18, decreased mesocarp discolouration15,19, and reduced incidence and severity of vascular browning19,20. Grafting of Hass onto Velvick or A10 rootstocks produced fruit with high Ca concentrations21. However, variation in rootstock effects on postharvest fruit quality has been reported across different locations and seasons. Therefore, it is difficult to predict and remains to be proved which rootstock, if any, may reduce fruit susceptibility to flesh bruising.
High turgor pressure in flesh tissue has been linked to greater bruise susceptibility in fruits such as apple and pear22. However, no such studies have investigated the relationship between turgidity and bruising for avocado. Nonetheless, greater lenticel damage has been reported in avocado fruit with high cell turgidity23. It can be reasoned that, as turgor pressure rises, cell wall elasticity decreases and fruit tissues could become more ‘brittle’ and, therefore, susceptible to physical damage. Fruit that are wet from rainfall or dew are likely to have high turgor pressure. Harvesting fruit in wet conditions promotes vascular browning and lenticel damage in Hass avocados24,25.
Precautions to reduce bruise susceptibility
Based on the above, recommendations for improved practices to reduce bruise susceptibility in avocado fruit have been summarised in Table 1. For some recommendations, a confirmed link with bruising susceptibility was established in the recent Hort Innovation project, Reducing flesh bruising and skin spotting in Hass avocado (AV10019). On the other hand, some recommendations are based on anecdotal or indirect evidence. These, in particular, need to be further investigated for adoption or not into commercial practice.
Table 1. Practices known or likely to reduce susceptibility to flesh bruising in avocado.
Future work
Producing more resilient fruit is one approach to addressing the flesh bruising problem. Another is to minimise exposure of the fruit to damage events that cause bruising, such as dropping or squeezing. The ongoing Hort Innovation project Supply chain quality improvement – Technologies and practices to reduce bruising (AV15009) will also identify tools, practices and other measures for reducing damage events in the supply chain. All project AV15009 findings are being incorporated into the Avocados Australia online Best Practice Resource (www.avocado.org.au/best-practice-resource/) and shared with two concurrent avocado supply chain quality improvement projects, Cool chain best practice adoption (AV15010) and Retailer point of purchase improvements (AV15011).
Acknowledgement The strategic levy investment Supply chain quality improvement – Technologies and practices to reduce bruising (AV15009) is a project under the Hort Innovation Avocado Fund, funded by Hort Innovation using the avocado research and development levy and contributions from the Australian Government. It is delivered by the Queensland Department of Agriculture and Fisheries in collaboration with The University of Queensland and Avocados Australia Ltd.
References
1. Tyas, J., 2016. Avocado industry fruit quality benchmarking. Final report AV11015. Horticulture Australia Ltd, Sydney.
2. Harker, F.R., Jaeger, S.R., Hofman, P., Bava, C., Thompson, M., Stubbings, B., White, A., Wohlers, M., Heffer, M., Lund, C., Woolf, A. 2007. Australian consumers’ perceptions and preferences for ‘Hass’ Avocado. Final report AV06025. Horticulture Australia Ltd, Sydney.
3. Opara, U.L., Pathare, P.B. 2014. Bruise damage measurement and analysis of fresh horticultural produce – A review. Postharvest Biology and Technology 91, 9-24.
4. Fairchild, M., 2013. Color appearance models. 3rd edition. Wiley, Sussex.
5. White, A., Woolf, A., Hofman, P.J., Arpaia, M.L., 2009. The international avocado quality manual. UC Davis Press, California.
6. Ledger, S.N., Barker, L.R., 1995. Black avocados – the inside story, Australian Avocado Growers Federation Conference – The Way Ahead, pp. 71-77.
7. Baryeh, E.A., 2000. Strength properties of avocado pear. Journal of Agricultural Engineering Research 76, 389-397.
8. Joyce, D.C., Mazhar, M.S., Hofman, P.J., 2015. Reducing flesh bruising and skin spotting in ‘Hass’ avocado. Final report AV10019. Horticulture Australia Ltd, Sydney.
9. Whiley, A.W., Rasmussen, T.S., Saranah, J.B., Wolstenholme, B.N., 1996. Delayed harvest effects on yield, fruit size and starch cycling in avocado (Persea americana Mill) in subtropical environments .2. The late-maturing cv Hass. Scientia Horticulturae 66, 35-49.
10. Bower, J.P., Cutting, J.G.M., Wolstenholme, B.N., 1989. Effect of pre- and post-harvest water stress on the potential for fruit quality defects in avocado (Persea americana Mill.). South African Journal of Plant and Soil 6, 219-222.
11. Golan, A., Kahn, V., Sadovski, A., 1977. Relationship between polyphenols and browning in avocado mesocarp. Comparison between the Fuerte and Lerman cultivars. Journal of Agricultural and Food Chemistry 25, 1253-1260.
12. Kahn, V., 1975. Polyphenol oxidase activity and browning of three avocado varieties. Journal of the Science of Food and Agriculture 26, 1319-1324.
13. Kosinska, A., Karamac, M., Estrella, I., Hernandez, T., Bartolome, B., Dykes, G.A., 2012. Phenolic compound profiles and antioxidant capacity of Persea americana Mill. peels and seeds of two varieties. Journal of Agricultural and Food Chemistry 60, 4613-4619.
14. Hurtado-Fernandez, E., Gonzalez-Fernandez, J.J., Hormaza, J.I., Bajoub, A., Fernandez-Gutierrez, A., Carrasco-Pancorbo, A., 2016. Targeted LC-MS approach to study the evolution over the harvesting season of six important metabolites in fruits from different avocado cultivars. Food Analytical Methods 9, 3479-3491.
15. Hofman, P.J., Vuthapanich, S., Whiley, A.W., Klieber, A., Simons, D.H., 2002. Tree yield and fruit minerals concentrations influence ‘Hass’ avocado fruit quality. Scientia Horticulturae 92, 113-123.
16. Witney, G.W., Hofman, P.J., Wolstenholme, B.N., 1990. Effect of cultivar, tree vigour and fruit position on calcium accumulation in avocado fruits. Scientia Horticulturae 44, 269-278.
17. Defilippi, B.G., Robledo, P., Ferreyra, R., Soto, S., Saavedra, J., 2015. Preharvest factors influencing ‘Hass’ avocado (Persea americana Mill.) quality during long term storage. Acta Horticulturae 1071, 137-141.
18. Everett, K.R., Boyd, L.M., Pak, H.A., Cutting, J.G.M., 2007. Calcium, fungicide sprays and canopy density influence postharvest rots of avocado. Australasian Plant Pathology 36, 22-31.
19. Marques, J.R., Hofman, P.J., Wearing, A.H., 2003. Rootstocks influence ‘Hass’ avocado fruit quality and fruit minerals. Journal of Horticultural Science & Biotechnology 78, 673-679.
20. Thorp, T., Hutching, D., Lowe, T., Marsh, K., 1997. Survey of fruit mineral concentrations and postharvest quality of New Zealand‐grown ‘Hass’ avocado (Persea americana Mill.). New Zealand Journal of Crop and Horticultural Science 25, 251-260.
21. Coates, L.M., Dann, E.K., Shuey, L.S., Smith, L.A., Dean, J.R., Cooke, A.W., Pegg, K.G., Hofman, P.J.,, Marques, R., Stubbings, B., Whiley, A.W., 2011. Effects of rootstock on avocado fruit quality – assessment of postharvest disease, major cations and biochemical traits. Proceedings of the 7th World Avocado Congress, 2011. Cairns, QLD, Australia, 206-214.
22. Garcia, J.L., Ruizaltisent, M., Barreiro, P., 1995. Factors influencing mechanical properties and bruise susceptibility of apples and pears. Journal of Agricultural Engineering Research 61, 11-17.
23. Everett, K.R., Hallett, I.C., Rees-George, J., Chynoweth, R.W., Pak, H.A., 2008. Avocado lenticel damage: The cause and the effect on fruit quality. Postharvest Biology and Technology 48, 383-390.
24. Duvenhage J., 1993. The influence of wet picking on post harvest diseases and disorders of avocado fruit. South African Avocado Growers’ Association Yearbook 16, 77-79.
25. Pak, H.A., Dixon, J., Smith, D.B., Elmsly, T.A., Cutting, J.G.M., 2003. Impact of rainfall prior to harvest on ripe fruit quality of ‘Hass’ avocados in New Zealand. Proceedings of the V World Avocado Congress, 2003, Granada -Málaga, Spain, 629-634.
See the latest marketing activity that’s helping Aussie consumers connect with (and eat!) Australian avocados. The industry’s marketing is provided by Horticulture Innovation Australia (Hort Innovation) and funded by the avocado marketing levy. Hort Innovation develops consumer-focused promotions using a variety of mediums including social media platforms such asFacebook, Twitter, Pinterest, Instagramand YouTube as well as targeted partnerships with consumer related publications and platforms.
MyFoodBook
Avocado fans are loving the content on MyFoodBook (www.myfoodbook.com.au), a recipe and cookbook community that includes more than 200,000 subscribers, and promotes recipes to more than 2.8 million people each month. Australian Avocados activity has involved a number of recipes being included on the website, with The Avocado, Garlic and Cheese Pull-Apart Bread performing particularly well – being viewed more than 18,200 times as of 1 June.
The Best Practice Resource (BPR) is our free online one-stop-shop to support best practice throughout the Australian avocado supply chains. Register here to access. If you are already registered, log in and check out the new BPR Library.
New Small Tree – High Productivity Initiative video
In 2013 work began on the Small Tree – High Productivity Initiative aimed at transforming the efficiency and productivity of Australian avocado, macadamia and mango orchards. The initiative has been inspired by productivity gains that have occurred in apple orchards, where increases in yields from 10 to 15 tonnes per hectare in the 1970s to 60 to 100 tonnes per hectare today have been achieved using modern high-density planting systems.
The Initiative includes multiple areas of research, including comprehensive field trials on trees planted at low, medium and high densities. A number of canopy management and training strategies aiming to keep the trees small and maximise yields as they mature are also being assessed. A feature of the Initiative is that these field trials are supported by fundamental research involving tree growth modelling using sophisticated computer programs and molecular biology to understand how the plants DNA controls flowering and vegetative growth. Identification of vigour managing rootstocks that restrict growth but not yield is another important aspect of the work.
This video ‘Unlocking the secrets to high orchard productivity’ outlines and illustrates the thinking behind the work and the key research areas.
