Banana variety research – Better Bananas

Yellow Sigatoka screening – agronomic evaluation trial (September 2018)

Posted on 2024-11-28 by Sarah Williams

Yellow Sigatoka screening – agronomic evaluation trial (September 2018)

Katie Robertson, Jeff Daniells, Carole Wright and David East, Queensland DAF (Dec 2022)

Four CIRAD hybrids demonstrated good resistance to yellow Sigatoka, but they did not measure up on their other agronomic characteristics. Seventeen Cavendish lines were assessed for resistance, but non were any better than Williams. All were rated as very susceptible to yellow Sigatoka.

Yellow Sigatoka, also known as Sigatoka leaf spot, is the major leaf disease affecting the north Queensland banana industry and is caused by the fungus Pseudocercospora musae. Most of the bananas grown are of the Cavendish type (mainly Williams), as well as a small amount of Lady Finger, both of which are very susceptible to the disease. The annual cost of controlling leaf disease in the north Queensland banana industry is estimated to be in excess of $25 million. The disease is particularly difficult to control under hot, wet conditions and an integrated disease management program involving both cultural and chemical measures is required for effective control. Fungicides are usually aerially applied to the leaf canopy at regular intervals throughout the year and represent the major ‘pesticide’ applied in the production of bananas in north Queensland.

It would be a great advantage to the industry if a commercially viable variety possessed disease resistance. The cost of production could be significantly reduced, as well as the industry’s overall pesticide input and any associated environmental impacts – perceived or otherwise.

As part of the project ‘Improved plant protection for the banana industry’ (BA16001), 24 varieties were screened for resistance to Sigatoka leaf spot at South Johnstone Research Facility during the 2022 wet season. The same block of bananas where the plant and ratoon crop agronomic evaluations reported previously (see here), was used for the disease screening trial. After the final ratoon crop, fungicide applications for leaf disease control ceased. The block was then nurse-suckered to synchronise development so that leaf spot could be rated on plants prior to bunching during the wet season in 2022. Counting from the first fully unfolded leaf down, the youngest leaf with 10 or more mature lesions (youngest leaf spotted – YLS) was recorded and the youngest leaf with 33 per cent necrosis of the lamina (YL33). The total number of functional leaves (TFL) was recorded if no leaf spot symptoms were present. Ratings were done on three separate occasions in the last week of March, April, and May 2022, respectively. For simplicity, just the YLS or TFL results averaged over the three rating occasions are presented here.

The new varieties have been given an overall disease reaction rating relative to three reference varieties that have had their susceptibility/resistance categorised in previous studies. All the Cavendish varieties were very susceptible and their YLS values were not significantly different to Williams, except for two of the TR4 resistant selections from Taiwan (GCTCV 105 and GCTCV 119) which had slightly lower YLS values. Our intermediate reference variety, Inarnibal, had on average two more leaves present with less than 10 mature lesions compared to the Cavendish varieties.

The CIRAD hybrids exhibited no leaf spot symptoms but only had 8 – 9 upright leaves on average. Nevertheless, they were considered highly resistant along with Dwarf Ducasse – the highly resistant reference variety.

The CIRAD hybrids certainly have leaves with good resistance to yellow Sigatoka, but those same leaves are relatively brittle and are prone to snapping, thus reducing the functional leaf area. Additionally, their cumulative yields in the preceding crops were 28-36% lower than that of Williams while also being 15-30% taller. CIRAD 924 and 938 had an acceptable taste and have also shown to be resistant to TR4 in the NT (along with CIRAD 931) but when all their characteristics are weighed up, there seems to be little commercial prospect for these varieties despite their good Sigatoka leaf spot resistance.

Youngest leaf with 10 or more necrotic lesions (YLS) for 24 varieties at South Johnstone (average of 3 rating occasions; error bars represent area 95% LSD). If the YLS stage was not reached for a variety (i.e. the CIRAD hybrids and Dwarf Ducasse) the leaf number represents the total number of functional leaves present. Williams (very susceptible), Inarnibal (intermediate) and Dwarf Ducasse (highly resistant) were used as references to assess the disease reaction of the new varieties.

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 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 Atherton Tablelands, FNQ (2023)

Posted on 2024-09-10 by Sarah Williams

Variety trials seeking resistance to Fusarium wilt Race 1 commence on the Atherton Tablelands

By Jeff Daniells, Kathy Grice, Katie Robertson, Kaylene Bransgrove and Sharan Muthukumar (April 2024)

Latest update...

Eight new Lady Finger-like bananas – some from Brazil and some from Queensland DAF’s mutagenesis efforts have been field planted on cooperating grower’s properties at Mareeba. They will be assessed for resistance to Fusarium wilt Race 1 over two crop cycles.

Background

Fusarium wilt of banana, also known as Panama disease, has plagued production of Lady Finger (AAB, Pome) in the subtropics of northern NSW and southern Queensland since early in the 20^th century. That widespread distribution of Fusarium wilt in southern production areas, combined with improved transportation and ease of mechanisation in the north, has contributed to major development of the Lady Finger industry on the Atherton Tablelands in the past 30 years or so. Currently about 280 ha are grown there – an industry worth about $15 million/year (Figure 1). It wasn’t too long though, before Fusarium wilt found its way onto a commercial Lady Finger farm on the Tablelands, with the first detection confirmed in 2008. Since then, several more farms have become affected, but damage on the Tablelands is typically not as severe as that in the south, because of the milder winters experienced.

Fusarium wilt is caused by the fungal pathogen Fusarium oxysporum f. sp. cubense. The relevant races described in Australia are Race 1, Race 2, Subtropical Race 4 (SR4) and Tropical Race 4 (TR4) which have to do with their banana variety host range. Lady Finger is susceptible to Race 1, SR4 and TR4. Within the races there is another division known as Vegetative Compatibility Groups (VCGs) which is particularly helpful for correct identification purposes. The VCG present on the trial farms is identified as VCG 0124/5 which is grouped in Race 1. This is the same as in previous trial sites in NSW and the north Queensland wet coast and is the most prevalent VCG recovered from diseased Lady Finger in Australia.

In previous banana plant protection projects, Fusarium wilt Race 1 screening has occurred at a field site in the subtropics of NSW. But due to budgetary constraints in the current Hort Innovation project – ‘New varieties for Australian banana growers’ (BA21002), the feasibility of conducting such trials on cooperating grower’s properties is now being examined on the Atherton Tablelands. So, two potential cooperating growers, that had sufficient Fusarium wilt disease present in their Lady Finger plantations, were identified at Mareeba in April last year. Tissue culture plants of the required varieties had been multiplied, were grown on in the glasshouse at South Johnstone and field planting occurred in October/November (Figure 2).

About the trial

Varieties

SCS451 ‘Catarina’ reported to have tolerance to Race 1 in the Brazilian subtropics has been planted. It is certainly the one to watch. In our agronomic trial at South Johnstone it has performed well with bunches of SCS451 throwing well clear of the throat, not choking like what often occurs with Santa Catarina Prata, which we have had in Australia since the late 80s (see Figure 3).
The four best tasting Goldfinger variants from the mutagenesis program have been included to confirm that they have retained resistance to Fusarium wilt Race 1.
Three Lady Finger and Silk hybrids from the EMBRAPA program in Brazil are also being evaluated.
As with other Fusarium wilt screening trials in the past we have included a few reference varieties with a range of known levels of disease reaction. They are the key to correct interpretation of results. It is not so much the absolute level of severity of disease present in the new varieties being tested, but rather how their level of disease severity compares with that of the reference varieties. Here we have included Dwarf Ducasse (very susceptible), Lady Finger (susceptible), High Noon (intermediate) and Goldfinger (resistant).

Disease inoculum

The trials were established in locations on the farms where Fusarium wilt was fairly widespread. Additionally, diseased pseudostem disks (about 5 cm thick) obtained from nearby blocks on the farm were placed in the bottom of each planting hole (Figure 4). This was to help enhance the uniformity of distribution of the pathogen and ensure that the roots of each plant in the trial were in close proximity.
The previous crop of Lady Finger on the sites was ‘knocked down’ in early/mid 2023 to allow for plant breakdown and cultivation of the rows prior to planting.
When any variety becomes diseased, the plan is to confirm by laboratory testing that the symptoms are due to VCG 0124/5.

Trial progress

Disease ratings will get underway as soon as disease symptoms become evident which is expected in the next few months.
Disease development will be assessed in a plant and ratoon crop.
Hopefully, we will get good indications from the Tableland trials of the disease response of the varieties. Selected varieties could then be considered for inclusion later, in pre-commercialisation sites in NSW and elsewhere.

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.

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

Posted on 2023-06-02 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.

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.

Observations and results

Observations and results are now available for:

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 2020-05-25 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.

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.

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.

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.

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 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%.

More information...

Video – Developing a standard industry banana carton

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.

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 TR4 variety screening trial

Posted on 2018-04-16 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).

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.

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.

Yellow Sigatoka screening – agronomic evaluation trial (September 2018)

Katie Robertson, Jeff Daniells, Carole Wright and David East, Queensland DAF (Dec 2022)

It would be a great advantage to the industry if a commercially viable variety possessed disease resistance. The cost of production could be significantly reduced, as well as the industry’s overall pesticide input and any associated environmental impacts – perceived or otherwise.

The CIRAD hybrids exhibited no leaf spot symptoms but only had 8 – 9 upright leaves on average. Nevertheless, they were considered highly resistant along with Dwarf Ducasse – the highly resistant reference variety.

More information

Variety trials seeking resistance to Fusarium wilt Race 1 commence on the Atherton Tablelands

By Jeff Daniells, Kathy Grice, Katie Robertson, Kaylene Bransgrove and Sharan Muthukumar (April 2024)

Latest update...

Background

About the trial

Varieties

Disease inoculum

Trial progress

More information will be made available as the trial progresses.

By Jeff Daniells and Katie Robertson

About the trial

Objectives

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.

Observations and results

More information will be made available as the trial progresses.

Results from the Subtropical packed product analysis

Minor defects

Abrasion and rub

Thrips damage

Bruising

More information...

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.

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...

TR4 variety screening trial

About the trial

Method of trial assessments

Trial results

Where to from here?

Did you know...

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!