Agronomic evaluation of new varieties South Johnstone screening trials (December 2022)

Posted on by Better Bananas
By Jeff Daniells and Katie Robertson

About the trial

Five new TR4 resistant Cavendish selections from Taiwan and eighteen TR4 resistant Cavendish from the Department of Agriculture and Fisheries’ mutagenesis program, were field planted at South Johnstone and are being assessed for agronomic performance. Some new Lady Finger types from Brazil are also included in a smaller subtrial.

New Variety trial dec 2022
The new Cavendish variety trial established at South Johnstone in December 2022.

Objectives

The Department of Agriculture and Fisheries imported new varieties as part of the ‘Improved plant protection for the banana industry’ project (BA16001) completed in 2021.  These varieties included some TR4 resistant Cavendish from Taiwan and various Lady Finger types from Brazil, which were released from quarantine in early 2022. Also during that project, 18 TR4 resistant Cavendish selections were made from the mutagenesis trials established earlier in the Northern Territory as part of the ‘Fusarium wilt Tropical Race 4 research program’ (BA14014).

The new trial at South Johnstone was field planted with these varieties in early December 2022. They will be evaluated for agronomic performance over two crop cycles as part of the project ‘New varieties for Australian banana growers’ (BA21002). This is a first look at many of these varieties to see how they perform under north Queensland conditions. In addition, preliminary taste panel assessments will be made.

In conjunction with this agronomic evaluation, several of these varieties are to be screened against TR4 in the Northern Territory to confirm their level of disease resistance. However, the banana freckle outbreak in the NT last year is contributing to delays in commencing this component of the broader work. The Lady Finger types will also be evaluated for Race 1 Panama disease resistance in an on-farm trial on the Atherton Tablelands.

Overview of varieties

There are five new Cavendish selections from Taiwan including Improved Formosana, which is reported as quicker cycling than standard Formosana and shorter in stature, and GCTCV 219 which has sweeter fruit.

There are eighteen Cavendish selections from DAF’s mutagenesis program.  They were derived from the already TR4 resistant CJ19 and GCTCV 215. The selections were made for improved agronomic characteristics, including plant stature, and having a cycle duration closer to Williams.

Ones to watch amongst the Lady Finger types from Brazil are SCS451, a selection of Santa Catarina Prata with tolerance to Race 1 Fusarium wilt, and the Sugar hybrid, Princesa.

Improved Formosana
Improved Formosana, a TR4 resistant Cavendish selection from Taiwan is included in the new trial (photo courtesy TBRI).

More information will be made available as the trial progresses.

This research has been funded as part of the project New varieties for Australian banana growers (BA21002), which is funded by Hort Innovation, using the banana industry research and development levies and contributions from the Australian Government. Hort Innovation is the grower-owned, not-for-profit research and development corporation for Australian horticulture. The Queensland Government has also co-funded the project through the Department of Agriculture and Fisheries.

Results from the Subtropical packed product analysis – minor defects

Posted on by Better Bananas

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 damage
Abrasion damage
Damage caused by flower rub (insert bag rub)
Damage caused by flower rub (insert bag rub)

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.

 
Flower Thrips Main image - if focused enough (low res)
Damage caused by Rust thrips
Damage caused by Rust thrips

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...

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.

Results from the Subtropical packed product analysis – major defects

Posted on 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. 

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...

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 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.

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...

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 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.

Panama TR4 variety screening trial

Posted on by Better Bananas

Contributions by:
Sharl Mintoff1, Samantha Cullen1, Chris Kelly1, Maxine Piggott1 and Jeff Daniells2
1Northern 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! 

Coastal Plains trial site
Plant crop of the 2018 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. 

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.

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

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. 

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 DITT).
Goldfinger variety showing good disease resistance (August 2019).

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 TR4 variety screening trial

Posted on by Better Bananas

TR4 variety screening trial

Panama disease tropical race 4 (TR4) is a major threat to the Australian banana industry. The availability of different varieties that are resistant to this soil borne disease is key to continuing to produce bananas in the presence of the disease. 

Variety screening trials have been established to assess the resistance of different banana varieties to Panama TR4. These trials are an important first step in finding a commercially acceptable alternative to the industry’s main variety ‘Williams’ Cavendish, which is very susceptible to the disease. 

The most recent variety screening trial conducted at the Coastal Plains Research Farm in the Northern Territory wrapped up in April 2018. This work was part of the research project, Banana Protection Program (BA10020) and results based on plant crop data are now available. Refer to the trial results below.

The new Improved Plant Protection for the Banana Industry (BA16001) project will continue this work with new trials at the site commencing in December 2018.   

About the trial

Conducted at the Coastal Plains Research Farm the trial was established on a site infested with TR4. In summary, the trial included:

    ⦁  27 varieties, planted in June 2016

    ⦁  plants artificially inoculated with Panama TR4

    ⦁  fortnightly disease ratings recorded

    ⦁  key agronomic characteristics of plant and first ratoon measured (time to bunching, bunch weight).

CJ19 first ratoon crop
CJ19 first ratoon crop
Formosana (GCTCV218) first ratoon crop
Formosana (GCTCV218) first ratoon crop
Dwarf Nathan plant crop
Dwarf Nathan plant crop
Williams — most plants did not survive the plant crop
Williams — most plants did not survive the plant crop

Method of trial assessments

All plants were artificially inoculated with colonised millet at planting. Four varieties with known response to Panama TR4 were used as references in the trial. These included:

    ⦁  FHIA-25 (Highly resistant)

    ⦁  Goldfinger (Resistant)

    ⦁  Formosana (Intermediate)

    ⦁  Williams (Very susceptible)

Assessments for the appearance of internal and external symptoms of the disease were undertaken on a fortnightly basis as well as at plant death or harvest.   

These assessments were undertaken on the plant crop as well as most of first ratoon plants. Unfortunately, in January 2018 a storm heavily impacted the trial three months prior to its intended finish. This meant that not all first ratoon information was able to be collected for all of the varieties. 

Coastal Plains variety screening trial (August 2017)
Coastal Plains variety screening trial after storm damage (January 2018)

The following categories were used to rank how susceptible or resistant varieties were to Panama TR4 in the plant crop.

Resistant (R): No disease symptoms were observed.

Intermediate (I): Majority of plants harvested with minimal plants showing symptoms or minor symptoms noted. With the appropriate crop management or environment to lower the inoculum levels these should be commercially viable. 

Susceptible (S): Majority of plants harvested with most plants showing disease symptoms.

Very susceptible (VS): Plants showing severe symptoms and >50% killed due to TR4 infection. 

Trial results

The following results of the plant crop have been reported by the project team as published in Australian Bananas Issue 52. 

Disease resistance ranking of plant crop

R = Resistant, I = Intermediate, S = Susceptible, VS = Very susceptible
* No disease observed, no signs of bunch at 12 months. 

Summary of results for plant crop

Where to from here?

The trial has produced some promising results, with four Cavendish varieties; CJ19, GCTCV 215, GCTCV 217 and Dwarf Nathan showing good resistance to Panama TR4 in the plant crop cycle. These varieties have been flagged as good candidates for mutagenesis. Mutagenesis is a breeding technique that uses gamma irradiation to promote changes in tissue cultured plants. The aim is to develop an improved variety that has commercially acceptable agronomic qualities, while maintaining its good resistance to Panama TR4. 

This trial work has already begun with CJ19 and Dwarf Nathan already undergoing mutagenesis. 

Future screening trials of new varieties will continue, with a new trial at Coastal Plains Research Farm due to commence in December 2018.  This work will be delivered as part of The New Improved Plant Protection for the Banana Industry (BA16001) project. 

Did you know...

In September 2017, several Far North Queensland growers visited the Northern Territory and saw the trial first hand.
The video below gives an overview of their visit and some of the grower’s impressions of the trial work being undertaken. 

This trial was part of the Banana Plant Protection Program (BA10020). This project was funded by Hort Innovation, using the banana research and development levy, and contributions from the Australian Government, with in-kind contributions from the Queensland Department of Agriculture and Fisheries, the University of Queensland and the Northern Territory Department of Industry, Tourism and Trade. Hort Innovation is the grower-owned, not-for-profit research and development corporation for Australian horticulture.