Banana Research – Page 3

Results from the Subtropical packed product analysis – major defects

Posted on 2020-05-25 by Better Bananas

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.

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...

Video – Developing a standard industry banana carton

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

Posted on 2020-05-25 by Better Bananas

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.

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.

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...

Video – Developing a standard industry banana carton

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

Posted on 2020-05-25 by Better Bananas

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.

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.

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.

More information...

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

Posted on 2020-05-22 by Better Bananas

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 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.

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.

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.

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.

More information...

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 disease TR4 variety screening trial

Posted on 2020-02-26 by Better Bananas

Contributions by:
Sharl Mintoff¹, Samantha Cullen¹, Chris Kelly¹, Maxine Piggott¹ and Jeff Daniells²¹Northern Territory Department of Industry, Tourism and Trade, Darwin, NT
²Queensland Department of Agriculture and Fisheries, South Johnstone, QLD

Latest update...

Main trial
Eight varieties have demonstrated better resistance to TR4 than Formosana, which include two Cavendish selections being considered for the next phase of pre-commercialisation trials. Three of the hybrids from the CIRAD breeding program in the French West Indies displayed better resistance than Goldfinger. Click here for results!

Sub-trial
Four parents with stellar TR4 resistance have been identified. This will assist international banana breeding programs to incorporate TR4 resistance into new varieties. Click here for results!

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.

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). This trial is part of the project ‘Improved plant protection for the banana industry’ (BA16001). The overall trial screened 31 varieties (including three reference varieties) and assessed their resistance to Panama disease tropical race 4 (TR4). In summary the trial includes:

Main trial

• 17 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.

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 were carried out fortnightly once external symptoms became apparent in a susceptible variety. Assessments included noting the appearance of external disease symptoms and internal symptoms at plant death or harvest. The trial ran for 20 months with most of the surviving varieties completing their first ratoon crop cycle. The final disease assessments were completed in August 2020. Click here for the plant and first ratoon results for the main trial.

More information...

This research has been funded as part of the project Improved Plant Protection for the Banana Industry (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 Industry, Tourism and Trade and contributions from the Australian Government. Hort Innovation is the grower-owned, not-for-profit research and development corporation for Australian horticulture.

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

Posted on 2020-02-26 by Better Bananas

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.

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.

JV 42.41 a hybrid Lady Finger type from Brazil. This variety has shown good disease resistance, bunch and finger size in the plant crop and the fruit looks and tastes like a traditional Lady Finger. (Photo courtesy of NSW DPI)

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

Posted on 2020-01-06 by Better Bananas

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.

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

Posted on 2020-01-06 by Better Bananas

David East

Unravelling the 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.

Banana bunch cover trial

Posted on 2019-08-06 by Better Bananas

The colour of your bunch covers may help control banana rust thrips

Banana rust thrips continue to be a significant pest for banana growers with levels of damage increasing in recent years. The thrips cause damage by feeding on the skin of immature banana fruit which causes reddish-brown marks. Growers are reporting that even fruit with low levels of damage are not meeting market specifications.

So what role does the colour of bunch covers play in rust thrips damage? Interest amongst researchers was sparked after previous work had shown that rust thrips respond differently to different coloured sticky traps. This prompted researchers to have a look into the effect that different coloured bunch covers have on thrips damage. The aim is to find non-chemical control methods as part of an Integrated Pest Management (IPM) strategy.

Initial trial results are encouraging and do show a difference in the level of damage caused by thrips depending on the colour of the bunch covers used. In this trial no chemical treatment was applied to the bunch after bell injection and the bunch cover was applied as per commercial timing. Orange, yellow and purple bunch covers showed damage above commercially acceptable levels in this scenario. The best performer was a paper bunch cover with a polyethylene ‘cloth’ liner. Light blue and white also produced similar low levels of damage compared with some other colours.

Finger length, colour and bloom were also assessed with results indicating that bag colour has no significant effect on these fruit quality attributes.

Based on the initial trial results growers should consider using bunch cover colours that have a low thrips damage rating. This coupled with standard insecticide treatments applied at bunch covering should provide the best level of control. Further work is underway to expand these results by testing new colour and liner combinations. Recommendations of the latest trial will be available to growers in the coming months.

More information

More information on trial and initial results

This research is 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 contributions from the Australian Government. Hort Innovation is the grower-owned, not-for-profit research and development corporation for Australian horticulture.

Banana bunch cover trial information

Posted on 2019-07-29 by Better Bananas

Effects of using different coloured bunch covers on banana rust thrips damage

About the trial

The trial looked into the effect that different coloured bunch covers have on Banana rust thrips damage. The aim is to find non-chemical control methods as part of an Integrated Pest Management (IPM) strategy.

The only chemical treatment applied in the trial was omethoate injected at bell emergence to ensure researchers were only measuring the influence that bunch covers had on rust thrips damage. This meant that there was no damage to the fruit before the bunch covers were put on.

As per commercial practice, bunch covers were placed on bunches when all the bracts had fallen off, approximately a fortnight after bunch emergence. At the time of bagging, the bell and the false hand plus one were removed.

Rust thrips damage was assessed at harvest by examining the surface of 5 central fingers from the top, middle and bottom hands of the bunch.

The presence and extent of damage on the fingers assessed was recorded using a scale of 0 to 4. Rating 1 is defined by a faint halo and is considered the maximum rating for a commercially acceptable level of damage.

Measuring the effect that bunch cover colours had on other fruit quality characteristics was also important to ensure they didn’t have a negative impact. The following fruit quality attributes were therefore assessed at harvest.

Finger length and diameter
Colour (Hue, chroma and lightness) of the peel at fruit colour stage 1 and 6
Bloom (the ‘lustre’ or ‘shine’ of the fruit) was assessed photographically to assess peel reflectance

* Note – Omethoate was registered at the time the trial was conducted and has since been deregistered. Before using any chemicals always check the current registration status and read the product label. Label and permit details can be accessed via the APVMA website, www.apvma.gov.au.

Results from the initial trial indicate that colours do play a role in level of rust thrips damage

The initial trial results showed a lot of variation in the damage caused by banana rust thrips with respect to different bunch cover colours.

Orange, yellow and purple bunch covers had levels of damage above commercially acceptable levels. Statistically, orange had a significantly higher level of damage compared to all other covers.

The best performer was a paper bunch cover with a polyethylene ‘cloth’ liner. This was the only bunch cover that had a liner in the initial trial. Therefore a new trial is looking at the impact of liners in combination with different bunch cover colours. Light blue and white produced similar low levels of damage as the paper bag.

Results also indicate that bunch cover colours have no statistically significant effect on finger length, diameter, colour and bloom.

Growers should consider using bunch cover colours with low thrips damage rating

Based on the initial trial results, growers should consider using bunch cover colours that scored a low thrips damage rating. Further work is underway to expand these results by testing new colour and liner combinations. Results of the latest trial will be available to growers in the coming months.

If you would like further information on this trial, contact the Better Bananas team.

This research is 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 contributions from the Australian Government. 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

Cut, hole or puncture

Pesticide residue

Cigar end rot

More information...

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

Subtropical packed product analysis

About the study

Results

More information...

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.

Results for Lady Finger fruit rejects

Subtropical banana reject analysis

More information...

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.

What causes fruit to be rejected?

Subtropical banana reject analysis

About the study

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

More information...

Contributions by:Sharl Mintoff1, Samantha Cullen1, Chris Kelly1, Maxine Piggott1 and Jeff Daniells21Northern Territory Department of Industry, Tourism and Trade, Darwin, NT2Queensland Department of Agriculture and Fisheries, South Johnstone, QLD

Latest update...

Sub-trialFour parents with stellar TR4 resistance have been identified. This will assist international banana breeding programs to incorporate TR4 resistance into new varieties. Click here for results!

About the trial

Trial progress

More information...

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

Latest update...

Why screen for disease resistance to Panama disease race 1

History of the Duranbah trial site

Current trial

New test helps product screening for Chalara management

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

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.

David East

Unravelling the mysteries of plant diseases

David EastPlant PathologistDepartment of Agriculture and FisheriesCentre for Wet Tropics Agriculture, South Johnstone, Qld

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.

The colour of your bunch covers may help control banana rust thrips

More information

Effects of using different coloured bunch covers on banana rust thrips damage

About the trial

* Note – Omethoate was registered at the time the trial was conducted and has since been deregistered. Before using any chemicals always check the current registration status and read the product label. Label and permit details can be accessed via the APVMA website, www.apvma.gov.au.

Results from the initial trial indicate that colours do play a role in level of rust thrips damage

Growers should consider using bunch cover colours with low thrips damage rating

Contributions by:
Sharl Mintoff¹, Samantha Cullen¹, Chris Kelly¹, Maxine Piggott¹ and Jeff Daniells²¹Northern Territory Department of Industry, Tourism and Trade, Darwin, NT
²Queensland Department of Agriculture and Fisheries, South Johnstone, QLD

Sub-trial
Four parents with stellar TR4 resistance have been identified. This will assist international banana breeding programs to incorporate TR4 resistance into new varieties. Click here for results!

David East
Plant Pathologist
Department of Agriculture and Fisheries
Centre for Wet Tropics Agriculture, South Johnstone, Qld