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Banana weevil borer Cosmopolites sordidus

Banana weevil borer

Banana weevil borer is found in all major banana growing areas throughout the world. Bananas and other species of the genus Musa are the only known hosts.

Often infestations of banana weevil borer will go unnoticed until the plant falls out, as most of the damage is done by the tunnelling of the larvae within the corm. In heavy infestations, tunnelling will extend for a short distance up the pseudostem, the presence of tunnels can be seen if the pseudostem is cut close to the soil surface. Other typical symptoms include reduced plant growth, choking, yellowing leaves, and weak or dying suckers. If infestations are detected, monitoring is essential to determine the levels present and appropriate management actions. 

Planting with clean material is essential to prevent banana weevil infestations. Plants from an accredited nursery are optimal, or the next best option is using clean planting material from your own farm.

Banana weevil borer
An adult banana weevil borer with scale.
Always use clean planting material to reduce the risk of a banana weevil borer infestation.

More information

For a general description for identification and detailed life cycle, seasonality and the damage that banana weevil borers can inflict on bananas click here

Monitoring should occur in peak times to determine whether chemical treatments are needed or not. To learn more about types of traps that are available for monitoring click here.

For information on how to manage banana weevil borer infestations and how to avoid infestations to begin with click here.

This information is adapted from: Pinese, B., Piper. R 1994, Bananas insect and mite management, Department of Primary Industries, Queensland and Treverrow, N., Pearley D., and Ireland, G 1992 Banana weevil borer : a pest management handbook for banana growers. : NSW Agriculture, North Coast Region; NSW Banana Industry Committee; Horticultural Research & Development Corporation.
This information has been updated as part of the National Banana Development and Extension Program (BA19004) 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.
Hort innovation logo

Goldfinger mutagensis trial—screening activities—Top 5 selections

Goldfinger mutagenesis—screening activities

Further screening and consumer and sensory evaluation of top 5 performers

Plants of the top 20 selections were nurse-suckered in December 2020 and the first bunches began emerging in June 2021. Agronomic data has been collected from all variants, but only fruit from the top five performers was sent down for consumer and sensory evaluation at DAF’s Coopers Plains facility in Brisbane. Variants 144, 211, 521, 544 and 903 were the top five tasting selections chosen to be further assessed in the larger consumer surveys.

Here, a much larger tasting panel was engaged to assist in identifying which variants are the most well-received by consumers and have the best market prospects for the future. Planting material is also in the process of being sent to the Northern Territory, where field trials will confirm if the variants have retained Panama disease resistance before they are included in DAF supervised pre-commercialisation trials.

This phase of the project identified four selections which were liked by consumers as much as Cavendish and Lady Finger (more detail here, pg 12-13).

Goldfinger consumer testing
Just over 120 consumers were recruited to taste-test the new Goldfinger selections in a controlled sensory environment, rating the fruit on characteristics relating to appearance and taste. This work was overseen by the Consumer Intelligence team, Simoné Moller, Ishita Pramanik and Philippa Lyons.
Goldfinger consumer testing
Whole banana samples being prepared for consumer analysis at the Health and Food Sciences Precinct in Coopers Plains, Brisbane. This work was overseen by the Consumer Intelligence team, Simoné Miller, Ishita Pramanik and Philippa Lyons.

Bunches of top 5 selections compared to unirradiated Goldfinger bunch

Normal Goldfinger bunch (unirradiated)

Bunches of the five variants selected to progress into the next phase of the investigation

This Goldfinger work was initiated as part of the Fusarium Wilt Tropical Race 4 Research Program (BA14014). At the close of BA14014 funding has been provided through the project Improved Plant Protection for the Banana Industry (BA16001) for continuation of the evaluations.   This project has been funded by Hort Innovation, co-investment from the Queensland 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.

Goldfinger mutagensis trial—screening activities—Initial screening

Goldfinger mutagenesis trial—screening activities

Initial screening

630 irradiated Goldfinger plants were sent to South Johnstone Research Station, in two batches during June and August 2017 where they were held in the glasshouse prior to planting. 

They were planted in the field in September and November 2017 respectively. Goldfinger plants which hadn’t been irradiated were also planted as control plants to compare against.

Irradiated plants in the field showed considerable variation in vegetative characteristics. This variation is mostly related to degree of dwarfness/plant height, pigmentation of pseudostem/leaf stalk and midribs, leaf uprightness/droopiness and minor leaf deformities. Also some of the irradiated plants have gross plant/leaf deformities and extremely slow growth. About 13% of the irradiated plants were in this reject category.

Harvest of both the September and November 2017 plantings were completed by the end of 2018. The photos below show the very large range in bunch and fruit characteristics which have been obtained by irradiation. Yes they have all come out of Goldfinger!

Postharvest assessments also revealed diversity in the eating quality of the Goldfinger variants. Several had qualities considered to be ‘improved’ and ‘better’ than the standard Goldfinger, including increased sweetness and firmness. Taste-testing sessions held amongst the staff at the research station were used to gauge consumer acceptance of these variants.

Twenty better tasting Goldfinger variants, which rated highly in the agronomic and post-harvest assessments were selected for a second stage of testing.

Several variants had qualities considered to be improved than the standard Goldfinger
Taste test survey
Postharvest quality assessments use the Brix scale to measure the sugar content of fruit

Examples of variation

Normal Goldfinger bunch (unirradiated)
Left is control that didn't undergo mutagenesis. Variant on the right has undergone mutagenesis and shows dwarfism and more upright leaves.
Left is control that didn't undergo mutagenesis. Variant on right shows changes to plant pigmentation as a result of mutagenesis.
This Goldfinger work was initiated as part of the Fusarium Wilt Tropical Race 4 Research Program (BA14014). At the close of BA14014 funding has been provided through the project Improved Plant Protection for the Banana Industry (BA16001) for continuation of the evaluations.   This project has been funded by Hort Innovation, co-investment from the Queensland 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.

Goldfinger mutagenesis trial – screening activities-Top 20 selections

Goldfinger mutagensis—screening activities

Screening of the top 20 selections

Following the selection of the top 20 variants from the original 630 plants, sucker and bit material from the original trial was planted in September and October 2019.

Bunches of the 20 variants began to emerge from the more established plants in March 2020 and continued throughout the year; the final harvest was performed in January 2021. Data was again collected on both agronomic performance and eating characteristics to substantiate the findings from the first investigation.

The taste panelling occurred once a week, with a maximum of six variants tasted in one session (including a Goldfinger and a Lady Finger ‘Dwarf Rossi’ as control samples to compare against). Panellists included colleagues who volunteered to taste the fruit under ‘controlled’ conditions at the research station and the family members and friends of those who took fruit home.

Each variant was tasted 3—4 times over the six-month trial period, except for variant 423 (which was only tasted twice due to late bunch emergence). Taste preference was ranked on a hedonic scale, which included the following categories: 1 = dislike extremely, 2 = dislike very much, 3 = dislike moderately, 4 = dislike slightly, 5 = neither like nor dislike, 6 = like slightly, 7 = like moderately, 8 = like very much, and 9 = like extremely.

Dwarf Rossi, the Lady Finger comparison, scored the highest overall rating (at 6.8) of all the varieties included in the taste panelling (Figure 1), corresponding with 77% of respondents indicating they would purchase it if it were commercially available (Figure 2). This was closely followed by variant 521, which was the best performer out of all the Goldfinger variants with an average rating of 6.5.

Figure 1: The average overall rating given to the variants across several taste panels (where 1 = dislike extremely, 5 = neither like nor dislike, and 9 = like extremely). The bars represent the standard error of the mean. Dwarf Rossi is a Lady Finger-type control included in the panelling as a reference variety
Figure 2: The percentage of respondents in the taste panelling who answered ‘yes’ (green) or ‘no’ (red) to the question, 'If this product was commercially available, would you choose to purchase it?' The remaining category (blue) are the instances where the question was left unanswered

Several comments were made that this variant had similar eating characteristics to a Lady Finger. The Goldfinger control was rated poorly, 4.7 on average, with 255 the only variant below it at 3.7. Variants 211, 544, 144 and 903 joined 521 in making up the five selections given the highest overall eating experience rating, and which also had the greatest number of people answer ‘yes’ to the question: ‘if this fruit was commercially available, would you choose to purchase it?’

The plant heights of all the selected variants were not significantly different from the 3.1 m Goldfinger average. The total fruit yield was also comparable to the average Goldfinger bunch (27.3 kg) for three of the selected variants, while the other two were 15—20% lower.

There were a couple of variants with undesirable characteristics which had gone undetected in the original selection of top performers. For example, several plants from one variant had severely fused fingers – to the point where several hands in a bunch were unusable.

Another variant had fruit which retained a green-tinge upon ripening. The relatively tall (3.5 m) and thin pseudostem            (54 cm) of another contributed to two of the ten plants snapping before bunch maturity; its brittle pseudostem also made harvesting difficult. Such issues prevented these three variants from being pursued further. 

March 2023 saw the final bunches of the second ratoon crop harvested from these twenty selections at South Johnstone. The agronomic results from nineteen of these selections are summarised in the accompanying table. Variant 255 was excluded after the first ratoon due to its excessive height and slender pseudostem, which made harvesting very difficult. Its fruit was also rated poorly in the South Johnstone consumer surveys.

The trial block has been nurse suckered and prepared for rating the susceptibility of the variants to yellow Sigatoka in the coming months.

Key observations from second ratoon:

Seven out of the nineteen selections had plant heights shorter than standard Goldfinger, which stood at 4.2 m. In most cases the pseudostem circumference was also smaller, meaning these plants remained proportionally comparable to Goldfinger.

Most variants had shorter finger lengths than the original Goldfinger by an average of 3 – 4 cm. The consumer study found this was generally regarded as preferable, as Goldfinger was rated as ‘too big’ by 46% of panellists.

Although variant 521 averaged a smaller bunch size (15% less than Goldfinger), its slightly faster cycle time meant the cumulative yield was not significantly different to Goldfinger. This was also the case for selections 119 and 339 (which were also aided by having slightly heavier bunches in the first ratoon).

In contrast, variants 544 and 144, which had similar second ratoon bunch weights to Goldfinger, had lower cumulative yields by 16 and 17%, respectively, due to lower bunch weights in the first ratoon.

Goldfinger second ratoon agronomic yield data
This Goldfinger work was initiated as part of the Fusarium Wilt Tropical Race 4 Research Program (BA14014). At the close of BA14014 funding has been provided through the project Improved Plant Protection for the Banana Industry (BA16001) for continuation of the evaluations.   This project has been funded by Hort Innovation, co-investment from the Queensland 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.

Silicon innovation trial

Using silicon fertilisers to improve Lady Finger tolerance to Panama disease race 1

By Stephen Norman

Background

Fusarium oxysporum f. sp. cubense (Foc) race 1 (Panama disease race 1) has been present in the north of New South Wales from the Tweed region south to Coffs Harbour for several decades and has had a devastating impact on growers of susceptible varieties in these areas.

Considered endemic in NSW, Panama disease race 1 is widely distributed across the region and has made it extremely difficult for Lady Finger growers to continue to produce this variety. As there are no control options for Panama disease race 1, the only alternative is to switch to growing those varieties that are resistant.

NSW silicon trial
Silicon trial site, February 2023

About the trial

The trial location is within the Tweed Valley of New South Wales and was planted in December 2021. A complete cycle of planned silicon treatment application has been carried out in collaboration and support with the grower. A new round of treatments will begin in late November 2022. 

As most NSW growers agree, 2022 was a challenging year due to the extended wet and cold periods. A combination of the sub-optimal growing conditions and isolated severe weather events has significantly slowed the growth of the bananas within the trial. The slowed growth reduced the infection rate, resulting in a lag of external symptoms. Our ability to record adequate data for early interpretation has been delayed. As the hotter months begin and growth rates increase, our ability to make accurate observations has improved.

Samples were taken in late September 2022 of suspect disease in plant tissue across the trial. It has been confirmed that Panama disease race 1 has infected the plants uniformly within the trial. This is good news for the trial efficacy. Uniform infection is paramount to measuring the silicon application’s effectiveness and its potential to improve tolerance to Panama disease race 1.

Latest update

Until March 2023, no external symptoms of Fusarium wilt were present, including the non-treated treatments (no silicon applied) within the trial.

nsw infected corm
Infected corm tissue sample
Suspected infected psuedostem
Silicon treatments applied in the trial

More information will be made available as the trial progresses.

This trial is a joint initiative between the NSW Department of Primary Industries, Southern Cross University, the University of Queensland, Agripower Australia and the Australian Banana Growers’ Council.

NSW SPI
This information has been prepared as part of the National Banana Development and Extension Program (BA19004) 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 (December 2022)

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.

Seasonal forecasting

Finger on the pulse with the latest climate and seasonal forecasting information

By Shanara Veivers

Weather data and information is an absolute necessity for any farmer to consider in making critical on-farm decisions. Those decisions can include when to plant, spray, irrigate and fertilise your crop. Even successful transportation of your crop can be dependent upon the cooperation of the weather. Having the advantage of knowing climate and seasonal conditions for your location in advance can be a significant benefit in protecting your crop and property.

Organised as part of the National Banana Development and Extension Project, a climate and weather workshop was held for the NextGen banana growers’ group and interested industry stakeholders at the Department of Agriculture and Fisheries (DAF) South Johnstone Research Station.

If you missed it, the workshop kicked off with participants reflecting on notable weather events and natural disasters experienced in the Cassowary Coast region from the early 1990’s to present. 

A series of interactive presentations, incorporating videos about important climate drivers and the new Bureau of Meteorology (BOM) forecasting tools and outlooks were presented by Dr Neil Cliffe (Manager for the DAF Drought and Climate Adaptation Program). Dr Cliffe spoke about important climate drivers that influence Australia’s highly variable climate.

Check out the Bureau of Meteorology video links below which explain how these drivers influence Australia’s climate:

 1. El Nino-Southern Oscillation (ENSO) –  One of Australia’s strongest climate drivers.

2. Madden Julian Oscillation (MJO) – An important driver of tropical weather around the globe.

3. Indian Ocean Dipole (IOD) – Most significant climate driver in the Indian Ocean. It refers to the year-to-year changes in tropical sea temperatures in the Western and Indian Oceans.

Tools

The BOM have developed new forecasting tools to assist farmers and agribusiness plan for extreme weather events and build stronger climate resilience into farming systems. These tools provide forecasts for 2 weeks to 3-month timeframes, filling a forecast gap not previously covered in the existing shorter and longer-term forecast products. Five new features on the BOM website include:

1.

Maps showing the likelihood of having extreme rainfall, maximum and minimum temperature for the weeks, months, and seasons ahead.

weather forecast rainfall
Map showing the likelihood of extreme rainfall for Camp Creek (South Johnstone) from Nov 2022 to Jan 2023.
Forecasting weather
Probabilities of the various deciles over the coming months for Camp Creek (South Johnstone) from Nov 2022 to Jan 2023, with a 76% chance of exceeding median rainfall in this period and a 45% chance of unusually wet conditions.

2.

Location specific data indicating shifts in rainfall and temperature probabilities compared to usual across the deciles/quintiles.

3.

Climate summary – Forecast timeline showing what has happened over the last few months, and what may happen in the next few months for rainfall and temperature.

Forecasting weather
Climate summary outlook from 1-29 Nov (2022) for Camp Creek (South Johnstone).
Forecasting weather
Probability of exceedance outlook from Nov 2022 to Jan 2023 for Camp Creek (South Johnstone).

4.

Probability of exceedance (rainfall only) shows the forecast chance of any rainfall total for any location.

5.

Three-day-burst forecast shows the chance over a 3-day period of getting a burst (15, 25, 50 or 75mm) of rainfall in total over those 3-days.

Forecasting weather
Three-day-burst outlook for the upcoming fortnight (12-25 Nov) for Camp Creek (South Johnstone).

Summary of extreme temperature, water and wind impacts on bananas

High temps
34oC or higher – leaf scorching, root growth stops & under peel discolouration occurs.
Other high temperature impacts – sunburn to stalk, fruit, and cigar leaf (most susceptible), impacts on bunch formation and differentiation.

Low temps

14oC or less – field chilling causing under-peel chilling & root growth stops.
Other low temperature impacts – water-soaked necks on fingers, frost damage, ‘winter yellows’ on leaves, and ‘November dumps’ on bunches.

 Waterlogging

More than 24 hours kills root tips; more than 4 hours reduced nutrient loading to 36%.
Other impacts – encourages production of aerenchyma tissue production in roots which improves gas exchange and potentially easier for Fusarium wilt fungi to infect roots.

Water deficit

Controlled deficits experiments have shown reduced productivity by 30-50%. 
Other impacts – plant stress; increased pest mites e.g., banana spider mite.

Wind

Highly susceptible to wind damage and don’t need cyclonic winds to produce damage.
Greater than 50km/h can blow down large, bunched plants.
Greater than 70km/h can cause 50-100% blow down.

Participant feedback

Growers and stakeholders who attended the workshop spoke highly of the event and took away knowledge that they felt will hemp them with making farm management decisions. 

“It was one the workshops that I’ve attended and enjoyed most. There was really good information, and I would attend an event like this again”.

“It is hard to get away from the farm sometimes, we are all busy, but we need to make effort to go to these things”.

“Some of the new tools can be used as a pre-emptive strategy, mapping out weather predictions and forecasts and its potential impact on fruit quality”.

“Great workshop and I really enjoyed the activity where we went through the historical data and made a timeline of weather events. Looking back at the historical data set the scene and was good information”.

We will continue to seek input from the NextGen group and other growers to drive the agenda for workshops, meetings and/or activities, to ensure they are relevant and useful. Topics and ideas suggested by participants at this workshop included: business management, leadership, banana agronomy and chemical impacts on bananas. These will be considered for future NextGen and wider industry activities.

The weather workshop was delivered as part of the National Banana Development and Extension Program (BA19004) 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 flower thrips

Flower thrips

Banana flower thrips (Thrips hawaiiensis) are a tiny pest frequently present in banana bunches. For most growers in Far North Queensland flower thrips are not the main bunch pest which leads to economic losses. However, large enough infestations can cause damage to fruit that does not meet market specifications. Damage caused by flower thrips is more significant in warm dry conditions with lower relative humidity, such as South East Queensland and northern New South Wales.

female Flower thrips to scale
Adult female flower thrips measure 1mm in length

Correct and timely bell injection is critical for the control of flower thrips. It must be performed when the bell is upright to ensure the insecticide solution provides protection to the entire bunch. Flower thrips are from the same family as Banana rust thrips (Chaetanaphothrips signipennis). Unlike banana rust thrips, flower thrips spend their entire life cycle on the banana plant, therefore, soil treatment does not provide control of flower thrips. 
 

Flower thrips cause damage to the peel of banana fruit from feeding and ovipositing (egg laying). These ovipositions resemble minute raised pimples on the young immature skin. These are readily seen because of a dark raised centre and can be confirmed by lightly touching the raised area with your fingertip. These oviposition marks almost disappear as the fruit matures. However, extensive damage from feeding from adult flower thrips can cause superficial scarring known as ‘corky scab’. This damage is usually confined to the lower hands (as flower thrips damage increases on lower hands as populations increase as they move down the bunch if it hasn’t been treated). Usually it is first noticeable on the outer whirl,  where the neck meets the cushion, but can extend to the outer curve of the fruit.  

Close up of flower thrips damageovipositions (pimples) on young banana fruit.
Severe flower thrips damage causing corky scab damage.

More information

This information has been prepared as part of the National Banana Development and Extension Program (BA19004) 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.

Banana flower thrips – general information and management

Banana flower thrips Thrips hawaiiensis

General information and management

Occurrence and seasonality

Banana flower thrips are common in banana flowers and among the fingers of newly emerged hands. This pest is found anywhere bananas are grown but its damage is more significant in the less humid, warm and dry climate of South East Queensland and northern New South Wales. Flower thrips are active throughout the year, with increased activity in January through to April. However, as long as flowers are present they can continuously breed.

Adult female flower thrips measure 1mm in length

Description and life cycle

Female flower thrips cause the most damage. They are 1mm long with a pale brown head and thorax and have a black abdomen. They are generally found sheltering under the bracts or inside the flowers. Male flower thrips are smaller (about 0.7mm long), uniformly cream coloured and tend to occur on the outer surface of the bracts.

Adults and nymphs are found on newly emerged bunches and invade the fruit early when the bunch is still covered by its bracts. Recent work has found that flower thrips are present very early in bunch development, inside the bell whilst it is still upright. Flower thrips breed all year round if flowers are present and migrate progressively down the bunch as bracts lift.  The lifecycle takes about three weeks in summer, with full development from the egg to the adult taking place on the bunch or in other parts of the plant.

Damage

Damage to fruit is the result of superficial scarring caused by feeding and ovipositing (egg laying). Oviposition damage resembles minute raised pimples on the young immature fruit skin. These have a dark raised centre and can be confirmed by lightly touching the raised area with the fingertips.

Extensive feeding damage causes a ‘corky scab’, a slightly raised grey corky skin covering. This damage is usually confined to the lower hands (flower thrips damage increases on lower hands as populations increase as they move down the bunch, if it is untreated). Usually, it is first noticeable on the outer whirl, where the neck meets the cushion, but can extend to the outer curve of the fruit. 

Monitoring

If flower thrips damage is being picked up in the packing shed, the best solution would be to speak to your bell injectors, revise training and ensure that bell injections are being performed correctly (right time and right position).

Flower thrips damage is easy to find in the shed, but it is also possible to find it out in the field. Monitoring for early detection of flower thrips can be done by examining bells of bunched plants every time you’re in the paddock. When large numbers of flower thrips are present, they cause bract-feeding patterns which are ‘lace-like’ in appearance and are lighter than the mauve bracts. These are more pronounced at trimming (when flower thrips populations are highest) and although bunches may already have damage, it gives you an early indication of high pest pressure allowing you to revise training with bell injectors, approximately 12 weeks earlier if assessing damage at harvest in the shed.

zoomed in bract feeding by flower thrips
Flower thrips feeding damage to bract, evident at trimming. Zoomed in for a clearer depiction of ‘lace-like’ feeding pattern.

Control

Chemical

Chemical control is best achieved with correct bell injection. Flower thrips can make their way between the bracts into the bell and damage very young fruit before bell injection. Therefore, to limit the extent of this damage, the timeliness of bell injection is important.  Inject bells whilst still upright. Increase the frequency of bell injecting during warmer months to account for increased plant growth (if possible, as short as every 4-5 days and extending out to every 7 days in winter). Always check the APVMA website for current chemical registrations before use. Below are insecticides currently registered (March 2023) and permitted for bell injection to control flower thrips.

Biological

A range of predatory bugs, predatory mites, ladybird beetles and lacewings can assist in reducing the build-up of flower thrips. Choosing chemical products that are less likely to kill these beneficial insects may assist in suppressing background pest populations.

More information

The Better Bananas team Department of Agriculture and Fisheries South Johnstone 07 4220 4177 or email betterbananas@daf.qld.gov.au

Download this information as fact sheets

This information is adapted from; Pinese,B., Piper, R 1994, Bananas insect and mite management, Department of Primary Industries Queensland

This information has been prepared as part of the National Banana Development and Extension Program (BA19004) 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 trial (October 2020)

Latest update...

Evaluation of the 2020 variety screening trial is progressing. Assessment of the plant crop is now complete and results are now available. Harvesting of the first ratoon was completed late in 2022 with data analysis underway. The new varieties are now being screened for yellow Sigatoka resistance.

About the trial

This agronomic evaluation screening trial was planted at South Johnstone Research Facility in October 2020. Building on previous variety evaluation work, the trial is looking at new introductions that may have commercial potential for the Australian banana industry, forming part of the recently completed project ‘Improved plant protection for the banana industry (BA16001)’.  

Assessment of agronomic traits is being collected over a plant crop and first ratoon with leaf spot screening performed in a nurse-suckered third crop cycle.

Trial five months after planting in March 2021.

Below is a video of a field walk of the evaluation trial taken in September 2021.

About the varieties being evaluated

Three Cavendish selections, four CIRAD hybrids, and six Lady Finger selections were included in the evaluation trial, including two varieties with TR4 resistance.

Observations and results

Observations and results are now available for the plant crop and will soon be available for the first ratoon.

What's next?

Currently, screening is underway to evaluate these selections for their tolerance to yellow Sigatoka. Plants will be assessed over three months during the wet season (March, April, and May 2023) and compared against control varieties with known resistance/susceptibility to this fungal leaf disease.

In December 2022, a new variety evaluation was planted as part of the project ‘New varieties for Australian banana growers (BA21002)’. This will again look at the agronomic traits as well as disease tolerance of recently imported varieties.

More information...

If you would like further information, feel free to contact the Better Bananas team via email at betterbananas@daf.qld.gov.au.

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.