Postharvest

Postharvest research and development

Postharvest research plays an important part in guaranteeing that Australian’s keep enjoying great quality bananas. A lot of time and effort goes into producing each and every bunch. Therefore, having correct postharvest processes in place for handling, storing and ripening fruit is essential to get the best quality fruit onto retail shelves and to maximise the fruit’s value back to growers.

Research looking into postharvest processes on-farm, as well as within the supply chain, has gone a long way in understanding and addressing some important quality issues. The links below provide more information on recent postharvest research.

If you have a postharvest issue that you would like to discuss or would like further information, contact the Better Bananas team at betterbananas@daf.qld.gov.au.

Results from the Subtropical packed product analysis – minor defects

Results from the Subtropical packed product analysis

Minor defects

There was a far greater number of minor defects than major defects found as part of the Subtropical packed product analysis. Results showed that of the 709 clusters, 235 or 31.15% had a minor defect. This is again over Woolworths specifications requiring no more than 10% of clusters with minor defects per consignment. 

The figure below shows 16 minor defects found in the study and lists them from the most common on the left through to less common on the right.

Proportions of minor defects (31.15% of consignment) identified during the packed product analysis.

The six most common minor defects which accounted for almost 70% of clusters included, abrasion, thrips damage, bruising, damage caused by rub, dry scars and sap stains.

Broadly speaking these minor defects can be addressed through altering in-crop management and handling practices, early identification of pests and establishing effective control methods and post-harvest handling and packing procedures. 

Abrasion and rub

Dry, brown and calloused to fresh, wet appearing, black patches on the peel. Caused by rubbing of bract, flower tip, leaf, bag or adjacent fruit against the peel or poor post-harvest handling. 

Abrasion and rub damage to fruit was the most common minor defect identified during the study. An accurate assessment of the reasons for abrasion and rub damage in your paddock will help guide which strategies are appropriate to reducing its impact.

 

Thrips damage

The damage caused by Flower and Rust Thrips can be significant. It was the second most common minor defect found during the packed product analysis. Effective management of these pests is possible through consistent crop monitoring and putting in place effective control strategies.

Damage causing bruising

Bruising

Occurs when enough impact or compression forces are applied to fruit. Appears as a flat, sunken or partially broken area of peel which will darken and become increasingly obvious as fruit ripens. 

Bruising proved to be a very common minor defect identified in this study and can be reduced by evaluating and adapting post-harvest handling strategies and equipment.

There are a broad range of reasons why physical damage may occur to bunches, such as abrasion, bruising, rub and dry scars. Some of these may be easily avoided and there are others that cannot be prevented. Rub, abrasion and dry scars caused by wind are not easily preventable. However, the use of clips-slips can be used to improve fruit quality, by placing between hands to reduce abrasion and rub of the bract, flower tip or adjacent fruit against the peel. Undertaking a cost-benefit analysis on the use of clips-slips may be a worthy exercise for the subtropical banana industry, as higher prices for blemish free fruit may very well outweigh the cost of use. 

Post-harvest handling is one area where small changes to equipment, techniques or practices can have large impacts on fruit quality. Changes to post-harvest handling on your farm should be investigated to determine whether small, cost-effective changes can be easily implemented to help decrease defects, increasing quality and ultimately profitability.

Thrips damage was the second most common minor defect found in this study and included damage from rust thrips and flower thrips, including corky scab. Effective management of these pests is possible through consistent crop monitoring and putting in place effective control strategies. Monitoring and control strategies for thrips species vary and should be tailored to your specific conditions before being applied on-farm.  

Sap stains are another minor defect that can be easily addressed with changes to post-harvest handling techniques and equipment. Packing too quickly, allowing de-handed clusters to sit for too long, failing to wash fruit in a trough and a lack of  paper/plastic sheets between fruit in cartons are a few factors that can increase the likelihood of sap stains. These can be addressed simply by training fruit packers or making changes to equipment and packing processes. Watch the ‘Developing a standard industry banana carton’ video for some handy information on best practice packing standards.

*Fruit in this study was assessed against the most recently released Woolworths subtropical Cavendish produce specifications, issued 9 December 2014. Always make sure you’re referring to the latest specifications relevant to your business.

More information...

A poster is now available showing common quality issues and packing guidelines for subtropical banana growers. To receive a hard copy or for more information contact NSW DPI Industry Development Officer Tom Flanagan on (02) 6626 1352 or email tom.flanagan@dpi.nsw.gov.au 

NSW DPI would like to acknowledge all growers who agreed to participate in the study, Matt Weinert, Leanne Davis from NSW DPI and Valerie Shrubb, Anastasia Van Blommestein and Brett Renton from WA DPIRD for undertaking the research. 

This research has been funded as part of the Subtropical Banana Development and Extension Program (BA16007), which is funded by Hort Innovation, using the banana research and development levy and co-investment from the New South Wales Department of Primary Industries and WA Department of Primary Industries and Regional Development. Hort Innovation is the grower-owned, not-for-profit research and development corporation for Australian horticulture.

Results from the Subtropical packed product analysis – major defects

Results from the Subtropical packed product analysis

Major defects

Let’s take a closer look at the major defects found as part of the Subtropical packed product analysis. Results showed that 4.65% of clusters in the consignment had a major defect. This is over the Woolworths’ specifications requiring no more than 2% of clusters with major defects per consignment. This could result in the consignment being rejected by the retailer. Although this number may sound small, the potential financial impact to growers is much larger, and that’s not even taking into account minor defects.

For example, if you were to receive $20 per carton for a consignment of 71 cartons, the total value is equal to $1,420. A grower could risk a reduction in the value or the complete rejection of their consignment in this instance. Further, the value of this potential loss doesn’t include any additional costs associated with packing or getting the fruit to market, such as transportation costs.

So, what were the major defects found and which were more common? The answer to those questions is presented in the figure below. All five of these are largely associated with poor post-harvest handling and packing procedures. 

Proportion of major defects (4.65% of consignment) identified during the packed product analysis.

Cut, hole or puncture

Physical damage that is deep enough to expose pulp. This may be caused by a knife, animal, bird or insect.

Cuts, holes or punctures were the most common major defect identified during the study and accounted for 45% of all major defects assessed.

Pesticide residue

White powdery residue on the surface of the peel from talc-based powder pesticide application.

Pesticide residue was identified as the second most common major defect and can be avoided by ensuring fruit are washed thoroughly prior to packing.

Cigar end rot

Fungus causes dry rot at the flower tip end of the finger with infection extending 10 to 20 mm into fruit. Affected area is blackened, becoming grey to white due to spores resembling ash on the end of a cigar.

The fourth most common major defect, Cigar end rot can be managed by implementing appropriate best management practices.

A cut, hole or puncture through to the pulp of the fruit was the most common major defect found in the study. There are a wide range of reasons that the pulp may become exposed before or after harvest such as de-leafing, de-handing, poor handling following harvest or animal and insect damage. Care needs to be taken to ensure that any affected fingers are found and removed prior to packing.

White residue from talc-based pesticides was the next most common major defect with immature or thin fruit, cigar end rot and live insects within a carton following in that order. It is possible to reduce the frequency of these issues with appropriate post-harvest handling and packing strategies. For example, washing fruit thoroughly prior to packing will remove any pesticide residue, whereas increased screening for underdeveloped fruit, or using callipers to check girth, would prevent thin and immature fruit from being packed. When applied to the data from this study, employing these two simple strategies could reduce the occurrence of major defects by 45%. 

*Fruit in this study was assessed against the most recently released Woolworths subtropical Cavendish produce specifications, issued 9 December 2014. Always make sure you’re referring to the latest specifications relevant to your business.

More information...

A poster is now available showing common quality issues and packing guidelines for subtropical banana growers. To receive a hard copy or for more information contact NSW DPI Industry Development Officer Tom Flanagan on (02) 6626 1352 or email tom.flanagan@dpi.nsw.gov.au 

NSW DPI would like to acknowledge all growers who agreed to participate in the study, Matt Weinert, Leanne Davis from NSW DPI and Valerie Shrubb, Anastasia Van Blommestein and Brett Renton from WA DPIRD for undertaking the research. 

This research has been funded as part of the Subtropical Banana Development and Extension Program (BA16007), which is funded by Hort Innovation, using the banana research and development levy and co-investment from the New South Wales Department of Primary Industries and WA Department of Primary Industries and Regional Development. Hort Innovation is the grower-owned, not-for-profit research and development corporation for Australian horticulture.

Subtropical packed product analysis

Is reject fruit causing growers to leave money on the table?

Subtropical packed product analysis

Supplying consumers with good quality fruit all year round is at the top of the list for many banana growers, especially in a competitive fresh fruit market. To do this however it’s important to understand why some fruit sent to market may not be up to spec.

About the study

In Coffs Harbour NSW, a packed product analysis was carried out to provide a clearer picture. It looked at fruit after ripening to see what issues were causing fruit to be rejected at retail outlets. The findings from this study provide growers and industry with information that can assist in recognising and addressing the most common reasons for fruit being rejected.

Fruit was assessed at Golden Dawn, a major banana ripening and wholesale company in the Coffs Harbour region. Assessments were made on fruit supplied by 12 banana growers, consisting of 71 cartons that contained a total of 709 clusters.

Sydney retail display of Lady Finger fruit

Fruit was checked against the most recent specifications released for Woolworths subtropical Cavendish produce, issued December 2014. These specifications have the most strictest criteria compared to other retailers. In broad terms, the specs state that ‘total minor defects should not exceed 10% of consignment’ and ‘total major defects must not exceed 2% of consignment’ with a ‘combined total not to exceed 10%’ of clusters with a defect. If defect levels are found higher than this, retailers are well within their rights to pay suppliers less for the fruit or reject the consignment entirely. This is what could have happened to the fruit that was assessed as part of this study. 

As an example, the potential loss of this consignment could be as much as $1420 (71 cartons @ $20/carton price).

This doesn’t include any additional costs associated with packing or getting the fruit to market, such as transportation costs.

Results

The results showed that 38% of all clusters inspected were deemed to have either a major or minor defect, more than 3 times above the levels specified by Woolworths. Figure 1 below provides a breakdown of that percentage and lists the most common defects found.

Results of fruit assessment showing percentage of clusters with major and minor defects. Assessment based on a consignment of 71 cartons.
Cuts, holes or punctures were the most common major defect identified during the study and accounted for 45% of all major defects assessed.

The findings of this study suggest that at present there is too much fruit with major or minor defects that is being packed, increasing the risk of consignments being rejected or their value reduced. As a result growers are potentially leaving money on the table.

However, the good news for growers is, there are opportunities to improve quality by taking a closer look at the defects found in this study. This includes simple and cost-effective changes that can be made in the paddock, in the pack shed and in the supply chain. All of these can increase profitability for growers and further improve the quality of fruit we see on retail shelves. 

A new banana packing poster is now available for subtropical banana growers. The poster highlights some of the most common banana defects identified in this study and provides a guide to help growers determine whether they should be packed or rejected. See below for details on how to get a copy.

More detailed information on the types of defects found in the study, as well as management strategies are available via the links below.

More information...

A poster is now available showing common quality issues and packing guidelines for subtropical banana growers. To receive a hard copy or for more information contact NSW DPI Industry Development Officer Tom Flanagan on (02) 6626 1352 or email tom.flanagan@dpi.nsw.gov.au 

NSW DPI would like to acknowledge the contributions made to this study by Geoff Bridgfoot, Paul Gibbins, Paul Thorburn, Kaye Adriaansz from Golden Dawn, Dave Norberry from D&D Ripeners, all NSW banana growers that supplied fruit.
This research has been funded as part of the Subtropical Banana Development and Extension Program (BA16007), which is funded by Hort Innovation, using the banana research and development levy and co-investment from the New South Wales Department of Primary Industries. Hort Innovation is the grower-owned, not-for-profit research and development corporation for Australian horticulture.

Results for Lady Finger fruit rejects

Results for Lady Finger fruit rejects

Subtropical banana reject analysis

The following are the results for reject Lady Finger fruit assessed as part of the Subtropical Banana Reject Analysis. The figure below shows the proportion of reject fruit that fell within each of the defect categories. As can be seen, pre-harvest physical defects were responsible for the rejection of 83% of all Lady Finger fruit assessed. Pest and disease defects accounted for 10%, whilst post-harvest defects were the cause of 7% of reject fruit. As was the case with results from the Cavendish assessment, pre-harvest defects again offers the greatest opportunity for improving fruit quality and reducing the number of rejected fruit. 

Proportion of Lady Finger fruit rejects that fall within the three defect categories

Let’s take a closer look at the defect types resulting in the rejection of Lady Finger bananas.  The graph below shows the 15 most prevalent defect types resulting in rejection of Lady Finger bananas. In descending order from left to right they account for almost 90% of all reject fruit for this variety. Again, there are several defects that cannot be prevented or doing so would require too much time and resources to make it financially beneficial. For example, misshapen fruit and doubles or fused fruit cannot be prevented to a large degree as they are caused by factors beyond our control. However, animal damage, rub, pruning damage and damage caused by bunch pests are issues that could addressed through changes to on-farm practices.

Proportion of defect types contributing to Lady Finger fruit rejects across all three defect categories
Animal damage was one of the largest causes of fruit rejection, contributing significantly to the total number of defects found for both Lady Finger and Cavendish fruit
The image provides an example of misshapen Lady Finger fruit evaluated in the study
The damage caused by Rust Thrips can be significant, highlighting the importance of having effective management strategies in place to manage this bunch pest

It is worth noting that misshapen fruit occurs more commonly in Lady Finger than Cavendish due to varietal differences in fruit development. However, it is believed that the dry conditions experienced across the NSW growing regions during the study  significantly worsened the problem, contributing to the high proportion of rejects resulting from misshapen fruit. Further reject analyses under ‘normal’ growing conditions or over a longer period would need to be undertaken to confirm this result.

The aim of this reject analysis study was to identify the predominant causes for rejection of fruit by growers within our subtropical banana growing regions. With a better understanding it will now allow resources to be best prioritised to address, demonstrate &/or trial innovative practices to reduce these defects. Overall reducing the quantity of fruit rejected through the implementation of cost effective practices will increase profitability. 

A poster is now available showing common quality issues and packing guidelines for subtropical banana growers. To receive a hard copy or for more information contact NSW DPI Industry Development Officer Tom Flanagan on (02) 6626 1352 or email tom.flanagan@dpi.nsw.gov.au 

NSW DPI would like to acknowledge all growers who agreed to participate in the study, Matt Weinert, Leanne Davis from NSW DPI and Valerie Shrubb from AGRIC for undertaking the research. 
This research has been funded as part of the Subtropical Banana Development and Extension Program (BA16007), which is funded by Hort Innovation, using the banana research and development levy and co-investment from the New South Wales Department of Primary Industries and WA Department of Primary Industries and Regional Development. Hort Innovation is the grower-owned, not-for-profit research and development corporation for Australian horticulture.

Subtropical banana reject analysis

What causes fruit to be rejected?

Subtropical banana reject analysis

Having less reject fruit, and consequently more marketable fruit, is a priority for many subtropical banana growers. To achieve this, the first step is to understand the causes of rejects before fruit leaves the farm gate. By identifying the main reasons for fruit rejection, we can focus our efforts on addressing the most common and impactful quality issues faced by growers. 

About the study

In a study carried out in the subtropical growing regions of NSW and WA, reject fruit was collected from 16 NSW packing sheds and 6 WA growers. Fruit was assessed to determine why the grower had thrown them into the reject pile. Growers included in the study were located from Coffs Harbour in the south through to Tweed Heads in northern NSW and in Carnarvon in WA. Varieties assessed in the study included Cavendish, Lady Finger, Ducasse and Little Gem. This article will focus on the results for Cavendish and Lady Finger due to their dominance in the industry. A total of 3469 Cavendish and 1189 Lady Finger fruit that did not make the grade were evaluated over the course of the study between June 2018 and May 2019.

Reject fruit collected from growers was evaluated and categorised into 1 of 36 different defect type categories

Reject fruit were assessed and separated into three general defect categories; Pre-harvest physical defects, pest and disease related defects and post-harvest physical defects. These three defect categories were further broken into 36 different defect types which are listed in the table below. 

The results of this study, in addition to discussion with growers, will assist the industry in prioritising research, development and extension activities most beneficial for increasing fruit quality and profitability in subtropical growing regions. 

Defect categories and defect types assessed during the reject analysis

Let's take a look at the results...

To begin with, let’s look at which defect categories the reject fruit fell into for both Cavendish and Lady Finger bananas. This will help us determine whether most of the fruit damage is occurring pre-harvest, post-harvest or as a result of pest and disease damage. 

From the graph below we can see that for both Cavendish and Lady Finger most defects are associated with pre-harvest physical defects (68%), with post-harvest physical defects (22%) and pest and diseases defects (10%) following in that order. Based on this we can conclude that pre-harvest physical defects accounted for the majority of rejections and that concentrating resources on addressing these defects could result in the greatest gains.

Proportion of rejects that fall within the three defect categories

The table below combines the reject data for both Cavendish and Lady Finger and ranks the 15 most prevalent defect types. Rows are colour coded to indicate which category the defect types fall under.

The 15 most prevalent defect types from the combined Cavendish and Lady Finger reject data

It must be noted that the high proportion of rejects resulting from misshapen fruit for both Cavendish and Lady Finger bananas is believed to be associated with the dry conditions experienced across the NSW growing regions during the study.  Further reject analyses under ‘normal’ growing conditions or over a longer period would need to be undertaken to confirm this result.

Now let’s take a closer look at which defect types were most common for both Cavendish and Lady Finger bananas. By examining the results in more detail, we will be able to determine which of the defect types are responsible for the largest proportion of reject fruit. Growers are then able to use this list to focus their efforts on specific causes of defects that could offer the greatest reduction in rejects for the smallest effort or cost.

 

This image provides an example of misshapen Lady Finger fruit evaluated in the study

More information...

A poster is now available showing common quality issues and packing guidelines for subtropical banana growers. To receive a hard copy or for more information contact NSW DPI Industry Development Officer Tom Flanagan on (02) 6626 1352 or email tom.flanagan@dpi.nsw.gov.au 

NSW DPI would like to acknowledge all growers who agreed to participate in the study, Matt Weinert, Leanne Davis from NSW DPI and Valerie Shrubb, Anastasia Van Blommestein and Brett Renton from WA DPIRD for undertaking the research. 

This research has been funded as part of the Subtropical Banana Development and Extension Program (BA16007), which is funded by Hort Innovation, using the banana research and development levy and co-investment from the New South Wales Department of Primary Industries and WA Department of Primary Industries and Regional Development. Hort Innovation is the grower-owned, not-for-profit research and development corporation for Australian horticulture.

Panama TR4 variety screening trial

Latest update...

Williams Cavendish was the first variety to express disease symptoms in April 2019, approximately five months after planting. Disease assessments have been undertaken on a fortnightly basis since this time.
Assessments of the plant crop are still in progress. However, initial observations are promising, with three more Cavendish types as well as some CIRAD hybrids and parental lines showing good disease resistance.

Coastal Plains trial site
Plant crop of latest screening trial taken in August 2019, 8 months after planting.

Panama disease tropical race 4 (TR4) continues to be a major threat to the Australian banana industry. Finding varieties that are resistant to Panama disease TR4 is a key component for continuing to produce bananas in the presence of the disease.

Over recent years variety screening trials have been running in the Northern Territory where the disease was declared endemic after its detection in the late 1990s. Work is well underway in the latest screening trial assessing resistance to Panama disease TR4 as well as agronomic traits. 

A mixture of varieties are being screened including Cavendish, novel CIRAD hybrids, and CIRAD parental lines. 

About the trial

Conducted at the Coastal Plains Research Farm the trial was established on a site infested with Panama disease tropical race 4 (TR4). In summary the trial includes:

Main trial

  • 18 varieties, planted in December 2018

  • plants artificially inoculated with Panama disease TR4

  • 24 plants of each variety (6 plants per replicate over 4 replicates)

  • randomised complete block design

  • three varieties with known response to Panama disease TR4 are included in the trial; Goldfinger                                   
    (resistant), 
Formosana/GCTCV218 (intermediate) and Williams Cavendish (susceptible)

  • fortnightly assessments.

Tissue culture plants received in mid-September 2018 (Image courtesy of Northern Territory DPIR).
Planting and inoculation occured in mid-December 2018 (Image courtesy of Northern Territory DPIR).

List of varieties

Sub-trial

The sub-trial consists mainly of parental lines from the CIRAD breeding program. This is a smaller trial in number due to difficulty replicating the lines using tissue culture. Results from this trial will provide useful information back to the breeding program on the level of resistance that parent material and hybrids have to Panama disease TR4. The trial includes:

17 varieties, planted in December 2018

plants artificially inoculated with Panama disease TR4

10 plants of each variety (1 plant per replicate over 10 replicates)

randomised complete block design

fortnightly assessments.

List of varieties

Trial progress

Williams Cavendish was the first variety to show disease symptoms in April 2019, approximately five months after planting. Disease assessments have been undertaken on a fortnightly basis since this time.

Assessments of the plant crop are still in progress. However, initial observations are promising, with three more Cavendish types as well as some CIRAD hybrids and parental lines showing good disease resistance. Results will be published when available.

Image of Williams Cavendish taken in late May 2019, approximately 6 months after planting. The plant crop showing external symptoms of Panama disease TR4.
Cut pseudostem of Williams Cavendish. Image shows severe internal symptoms of the disease, with discolouration and blockage of vascular tissue. (Image courtesy of Northern Territory DPIR).
Goldfinger variety showing good disease resistance (August 2019).

More information...

This research has been funded as part of the Improved Plant Protection for the Banana Industry Program (BA16001), which is funded by Hort Innovation, using the banana research and development levy, co-investment from the Department of Agriculture and Fisheries and the Northern Territory Department of Primary Industry and Resources and contributions from the Australian Government. Hort Innovation is the grower-owned, not-for-profit research and development corporation for Australian horticulture.

Panama R1 variety screening trial

Panama disease race 1 variety screening trial (Duranbah, NSW)

Latest update...

The following varieties are growing well in the presence of Panama disease race 1 (R1) in the latest screening trial:

   • Brier—a Dwarf Cavendish selection from the Canary Islands

   • D5—a Cavendish clone from South Africa

   • JV 42.41—a Lady Finger hybrid from Brazil.

Three ‘best bet’ varieties, PKZ, FHIA-17 and FHIA-25 were selected from the previous Banana Plant Protection Project (BA10020). PKZ and FHIA-17 are dessert cultivars and FHIA-25 is a cooking banana. In February 2018, these varieties were established in a semi-commercial planting, with the first bunches harvested in August 2019. This trial aims to develop growing, ripening and handling recommendations and to undertake consumer acceptance testing of these varieties. 

Due to interest from local markets, niche varieties such as Pacific Plantain and Santa Catarina Prata have been planted at the trial site. These varieties were not included in the disease screening trial, however observations since planting indicate these varieties are susceptible to the disease.

Why screen for disease resistance to Panama disease race 1

If you are a non-Cavendish grower, then you are likely to already know the answer. Panama disease is caused by a soil borne fungus Fusarium oxysporum f.sp. cubense. The disease initially infects the banana plant through the roots, then moves through the plant into the vascular system inside the pseudostem.  It eventually blocks the vascular tissue causing plant death. Different strains of the disease are known as races. Panama disease R1 is present in many production regions in Australia and infects varieties such as Lady Finger, Ducasse and some cooking bananas, but not Cavendish. Finding banana varieties with resistance to Panama disease R1 is the focus of the subtropical variety evaluations underway at Duranbah, NSW. Results from the Duranbah trial should be relevant to all subtropical growing areas with Panama disease R1.

Dwarf Ducasse at trial site showing external symptoms of Panama disease race 1.
Cut pseudostem of Dwarf Ducasse showing internal symptoms of Panama disease race 1.

History of the Duranbah trial site

Panama disease R1 wiped out a Lady Finger plantation on the current Duranbah site over 30 years ago. The land was then used to grow other crops, including avocados, and was fallow for several years before the trial began. Now the site is used for variety screening evaluations, with the initial trial planted in February 2012 as part of the Banana Plant Protection Project (BA10020).

The variety Lady Finger is very susceptible to Panama disease R1 and tissue cultured plants of this variety were grown on the site initially to confirm the continued presence of the disease. To guarantee the disease was evenly distributed when the trials were conducted, infected millet seed was incorporated into each planting hole, ensuring each plant in the trial is being assessed under the same disease pressure. 

The initial trials included three phases: 

Phase 1 – plants were grown with the sole purpose of determining if they survived Panama disease R1.

Phase 2 – varieties that showed Panama disease R1 resistance were grown to collect growth data including plant height, girth, cycling time and bunch data.

Phase 3 – standout varieties, called ‘best bets’, are being grown in semi-commercial plantings to determine ripening and handling conditions and to undertake consumer acceptance. Phase 3 is happening in the current project,  the Improved Plant Protection Program for the Banana Industry BA16001.

Twenty-nine different varieties have been or are currently being screened for resistance to Panama disease R1. In BA10020, 13 varieties were tested and 16 are in the current trial which is part of BA16001. 

Current trial

Sixteen local and imported varieties are currently being screened in the Panama disease R1 high pressure site. Varieties are rated according to their resistance or susceptibility to the disease by rating both the development of external and internal symptoms. External symptoms include yellowing of leaves and splitting of pseudostem, while vascular discolouration is rated internally at harvest or when plants die. Samples from plants suspected to be infected with Panama disease R1 are sent for laboratory diagnostics to confirm the presence of the disease.

The plants in this evaluation were deleafed and desuckered as per commercial practice and growth data, including cycle time, bunch weight, number of fingers and finger size are being collected.

Varieties that are showing good disease resistance at the plant crop stage in the latest screening trial include: 

   • Brier – a Dwarf Cavendish selection from the Canary Islands

   • D5 – a Cavendish clone from South Africa 

   • JV 42.41 – a Lady Finger hybrid from Brazil.

The three ‘best bets’ varieties, PKZ, FHIA-17 and FHIA-25 were established in a semi-commercial planting in February 2018, in a separate block from the disease resistance evaluation trial. These varieties are managed in accordance with commercial practices to evaluate their agronomic performance under typical subtropical growing conditions. The first bunches were harvested in August 2019. Agronomic data is being collected from these plantings and the fruit is being used to develop growing, ripening and handling recommendations, and to undertake consumer acceptance testing. PKZ and FHIA-17 are dessert cultivars and FHIA-25 is a cooking banana.

And finally, due to interest from local markets the trial is also looking at some niche varieties such as Pacific Plantain and Santa Catarina Prata. Unfortunately, early observations indicate that these varieties are susceptible to Panama disease R1.

'Best bet' block in May 2019, established to evaluate the agronomic performance of banana vareities PKZ, FHIA-17 and FHIA-25.
Brier bunch. Brier is a Dwarf Cavendish selection from the Canary Islands growing well in the presence of Panama disease R1.

List of varieties

This research has been funded as part of the Improved Plant Protection for the Banana Industry Program (BA16001), which is funded by Hort Innovation, using the banana research and development levy, co-investment from the Department of Agriculture and Fisheries and the New South Wales Department of Primary Industries and contributions from the Australian Government. Hort Innovation is the grower-owned, not-for-profit research and development corporation for Australian horticulture.

New test helps product screening for Chalara management

New test helps product screening for Chalara management

Multiple fungal organisms are known to cause Crown end rot (CER) in bananas. The following research is focused on the more serious form of CER commonly known as Chalara where the rot extends into the fruit (caused by Thielaviopsis musarum). Disease symptoms are typically observed in the supply chain during cooler periods of the year (winter). Chalara is sporadic in occurrence, making it difficult to conduct research trials with the disease. Department of Agriculture and Fisheries researchers have now developed an inoculation technique that mimics the development of Chalara in the supply chain, enabling researchers to screen and evaluate alternative management options.

There are two post-harvest fungicides currently registered for use in Australia to help manage CER. Although these treatments are effective against the fungi that cause CER, growers have expressed a need for non-chemical options for managing the disease, particularly those with organic status.
The inoculation technique has now been used to determine efficacy of the currently registered fungicides, alternative fungicides and biological products.

Results

Overall, the inoculation technique developed is rapid and reliable and the results are reproducible. Even though the technique was specific for Chalara (T. musarum), crown mould assessments were also obtained. Ideally a successful test product should have efficacy against T. musarum and the range of fungi that cause crown mould.

Prior to conducting this research there was only anecdotal evidence that the current registered projects had efficacy against T. musarum, but this has now been confirmed, with both Tecto® and Protak® effective in halting the development of Chalara. Results also showed that some biological products are capable of managing Chalara and reducing levels of crown mould.
Participating companies have been supplied the results for their products. They can use the results to support registration applications and/or determine which products are worth investing in further trials. It is hoped this work will lead to product registration adding alternative management options for growers.
Crown end rot
Fruit inoculated in suspension of T. musarum (concentration is 1 million spores per ml).
Crown end rot
Fruit artificially inoculated with T. musarum. This photo was taken one week after inoculation, following storage and ripening under near commercial conditions.
Crown end rot
One alternative fungicide and one biological product provided excellent management of T. musarum. Photo taken of alternative fungicide.

Remember...

Before using any chemicals, always check the current registration status and read the product label. Label and permit details can be accessed via APVMA website: www.apvma.gov.au
This work was undertaken as part of the ‘Enhancing the outcomes of BA13011-Crown end rot investigations’ funded as part of Department of Agriculture and Fisheries’ Horticulture and Forestry Science development funding. 

Meet a researcher – David East

David East

Unravelling the little mysteries of plant diseases

Agriculture has always been a big part of David’s life. Growing up on a mixed grazing property just north of Orange in the Central Tablelands of NSW, he went on to study Systems Agriculture at The University of Western Sydney. After finishing Uni, David worked in the cotton industry in Western NSW before taking an opportunity to manage a large forestry nursery. It was David’s career in the forestry sector that led him to move to Tully with his young family, managing propagation for a large forestry company. In 2014, David decided on a different career path, taking on a technical laboratory position with the Department of Agriculture and Fisheries based at South Johnstone.
Since joining the Department David has forged a successful career in plant pathology.  His current research work involves a yellow Sigatoka leaf spot trial, evaluating the effectiveness of new chemistry and ‘softer options’ for control. In addition to this work, he is also busy providing general diagnostics for the banana industry.
David East
Plant Pathologist
Department of Agriculture and Fisheries
Centre for Wet Tropics Agriculture, South Johnstone, Qld
We asked David what is the most exciting part of his research. ‘The most exciting part of my current research is exploring new solutions to perennial problems within the banana industry. The most enjoyable part of my job is diagnostics. Each sample is its own little mystery. It is incredibly satisfying to identify the problem, explore the factors that led up to issue, and to advise ways to avoid it happening again’. 
Outside of the lab David enjoys gardening, spending time with his family, playing guitar and fishing. His favourite banana recipe is banana bread, which he often enjoys for smoko.