Biofumigant Cover Crops at Work

The use of specialised cover crops which are grown, mulched and incorporated into the soil prior to cropping is known as ‘biofumigation’.

The fumigation effect is caused by plant compounds called cyanogenic glucosides or glucosinolates.  These are found in Brassica species such as cabbages, radish and cauliflowers;  it’s the odour that you smell as you drive through the Lockyer Valley!

When these are broken down, these naturally occurring compounds from the biofumigant plants are effective in suppressing soil-borne pests, diseases and weeds.  They can be particularly effective in getting the jump on nematodes.  Other benefits of using biofumigant cover crops is the addition of rich organic matter and a consequential improvement of soil structure and fertility.

There are over 200 glucosinolates commonly found in Brassica species and work is currently underway in the region to identify more accurately, which species are most effective for specific pests and diseases.  The Department of Agriculture and Fisheries have recently established a trial of different biofumigant crop types at the Research Facility in Bundaberg, and are also doing an on-farm demonstration  with some local growers.  They have developed a poster on their trial findings to date – download here.

For further reading on the benefits of incorporating a biofumigant cover crop into your vegetable crop rotation, download this factsheet which has been developed through the Soil Wealth Program.

Sources:

  1. Biofumigation Fact Sheet – Soil Wealth and Integrated Crop Protection (VG16078) – http://www.soilwealth.com.au
  2. Queensland Department of Agriculture and Fisheries, 2018.

Acknowledgements: 

Post written by Michelle Haase – Vegetable Industry Development Officer (VegNET) with Bundaberg Fruit & Vegetable Growers – www.bfvg.com.au. Funding for the VegNET National Vegetable Extension Network program is from Hort Innovation with vegetable grower levies and funding by the Australian Government.

TPP Surveillance Update

Tomato Potato Psyllidd (TPP) is an exotic pest.  Although only tiny at 3mm in length, this sap-sucking insect is considered a major biosecurity threat for vegetable growers.

An adult TPP resembles a miniature cicada or a winged aphid.  It has a dark, brownish coloured body with white or sometimes yellow markings, and transparent wings which are held vertically over its body.  When disturbed, the adult TPP gives a characteristic wiggle of the abdomen and then jumps vertically or takes flight.

TPP has a wide host range – tomatoes, potatoes, capsicums, chillies, eggplants, tamarillos and sweetpotatos – and is easily spread via plant and equipment, plant materials, by wind and/or by its own means (flight!).  It therefore has all the hallmarks of pest potential to cause significant vegetable losses.

Signs and symptoms of a TPP infestation include;

  • adult psyllids jumping from foliage when disturbed
  • severe wilting of plants caused by psyllids feeding
  • stunting and yellowing of growth tips, and/or yellowing of leaf margins
  • cupping or upward curling of leaves
  • small white sugar-like granules coating leaves and stems, attracting ants and sometimes the growth of sooty mould.

Early season detection and management is critical to minimise psyllid reproduction and spread. Both commercial vegetable growers and backyard gardeners are urged to check for signs of TPP.  Plant Health Australia, the Queensland Department of Agriculture and Fisheries, and Agriculture Victoria have an excellent range of images of TPP in the various stages of development online, to assist in accurate identification.

TPP was detected in Western Australia last year, leading to a significant expansion of TPP surveillance by each State government throughout the country.  The TPP Surveillance Overview Program supported this surveillance effort through the provision of more than 3,000 sticky traps to interested industry stakeholders to monitor for TPP.

Between April 2017 and 2018 over 1,100 traps have been returned to TIA and assessed. No TPP were detected.

Tasmanian Institute of Agriculture (TIA), 30 April 2018

Surveillance is an extremely important aspect of TPP monitoring – all data collected from these traps is used to support each state in Area Freedom (AF) certificates as proof of TPP absence. AF certificates and evidence of TPP surveillance are needed to maintain access to trade markets.

The TPP Surveillance Overview Program is operated by the Tasmanian Institute of Agriculture (TIA) with funding by Hort Innovation.  The TPP surveillance program has been extended for a further two months until a national approach to TPP surveillance is developed.

Bundaberg Fruit & Vegetables Growers can supply growers with a monitoring kit; TIA will continue to assess returned sticky traps until the end of July. For a sticky trap monitoring kit to be sent to you, contact BFVG’s VegNET Officer Michelle Haase.  To stay up to date with the TPP Surveillance Program, check out the UTAS website – here – or email the Project Coordinator Raylea Rowbottom.

Reporting of TPP is mandatory and can be done by contacting Biosecurity Queensland on 132 523 or the 24 hour emergency pest hotline – 1800 084 881.

Source & Acknowledgements:  Post written by Michelle Haase – Vegetable Industry Development Officer (VegNET) with Bundaberg Fruit & Vegetable Growers – www.bfvg.com.au. Funding for the VegNET National Vegetable Extension Network program is from Hort Innovation with vegetable grower levies and funding by the Australian Government.

Information supplied by Tasmanian Institute of Agriculture – utas.edu.au/tia.  Images courtesy of Department of Agriculture and Food, Western Australia.

 

 

Pest and Disease Resources for Vegetable Growers

These hot and humid conditions are perfect breeding grounds for a whole range of pests and diseases affecting vegetable crops.  There are a heap of resources available to growers advising on pest and disease mitigation options, so much so one easily runs the risk of information overload.

Some handy resources however which are well worth looking at have been developed with funding through Hort Innovation with grower levies.  One of these is an easy to read fact sheet and a must read for growers of capsicums and chillies in the Wide Bay-Burnett;  How can I control pests? Options for controlling high priority pests in capsicums and chillies.  This factsheet contains information on control options for high priority pests in capsicums and chillies.

It’s part of a series that provides detailed information on registered and permitted pesticides for disease, insects and weeds. Other publications in the How can I control pests? series are;

  1. Options for controlling high priority pests in cucumbers
  2. Options for controlling high priority pests in brassica vegetables
  3. Options for controlling high priority pests in brassica leafy vegetables
  4. Options for controlling high priority pests in celery
  5. Options for controlling high priority pests in carrots
  6. Options for controlling high priority pests in lettuce

 

Sources:

  1. Soil Wealth website – www.soilweath.com.au

Acknowledgements: 

Post written by Michelle Haase – Vegetable Industry Development Officer (VegNET) with Bundaberg Fruit & Vegetable Growers – www.bfvg.com.au. Funding for the VegNET National Vegetable Extension Network program is from Hort Innovation with vegetable grower levies and funding by the Australian Government.

 

 

Fruit fly season warming up

Following on from the hottest winter on record, fruit fly has unfortunately already made its presence felt in the Wide Bay-Burnett. In fact, local agronomist at Total Grower Services, Eddie Dunn, was seeing evidence of fruit fly back in August, while out scouting for signs of other pests and diseases.

“October is the usually the time of year that they are at their worst, but it looks as though their peak period was a bit earlier than usual this year,” said Eddie.

Fruit fly, or ‘Qfly’, is Australia’s most significant horticultural pest and a major biosecurity problem on both the domestic and international market. Adult fruit fly lay their eggs in ripe fruit and the larvae feed on the flesh of the fruit making it unsightly, inedible and unmarketable. As cover spray options for fruit fly control become fewer (due to increasing pest resistance to pesticides) growers are increasingly required to resort to other tools for managing pests.

Dr Jenny Ekman of Applied Horticulture Research (AHR)  has put together an excellent resource on identifying and managing fruit fly, called Fruit Fly Management for Vegetable Growers. The guide has lots of close up photos of fruit fly in all stages of its life cycle and loads of information on farm hygiene practices that can assist in the management of fruit fly.  You can download a copy of the guide here.

Other resources available online to growers on managing fruit fly is a fantastic series of short videos (also created by AHR) called Controlling Fruit Fly in Vegetables.  The series is broken up according to topic – targeted control, monitoring, food based baits, male annihilation/female-biased traps, and netting/repellents and field hygiene.  Each video is only 2 to 4 minutes long and worthwhile watching. The Department of Agriculture and Fisheries (DAF) also has extensive information online, not only on fruit fly but many other horticulture pests (including fruit spotting bug, which was the one that Eddie was looking out for) – you can check out their A-Z list of horticulture pests here.

To stay connected with BFVG and for further resources/information on events in the Wide Bay-Burnett region, go to our website or subscribe to our Fresh Pickings newsletter.

Sources:

  1. Dr Jenny Ekman, Applied Horticulture Research. Fruit Fly Management for Vegetable Growers.
  2. Photo credit: Dr Jenny Ekman, Applied Horticulture Research. Fruit Fly Management for Vegetable Growers.
  3. Queensland Government. (2012) A-Z List of Horticultural Pests (website).

Acknowledgements: 

Funding for the VegNET National Vegetable Extension Network program is from Hort Innovation.

 

 

 

Moth de resistance!

Insecticide resistance is a major issue for growers in managing pests.  The Diamondback moth (DBM) is top of the stakes when it comes to out-competing those in the business of keeping pests at bay.

Growers of cruciferous crops are all too familiar with the DBM, also known as cabbage moth or Plutella. DBM has an unrivalled ability to develop resistance to all classes of insecticides and is potentially the most damaging and difficult to manage pest of brassica vegetable crops. The cost of controlling DBM globally is estimated to be between $4 and $5 US billion per year; it is considered the most economically important pest of cruciferous crops in Australia.

Sustainable management of DBM requires the adoption of flexible integrated pest management strategies. As DBM continues to outsmart growers, researchers at the University of Queensland have been conducting research into how the DBM metabolically detoxifies insecticides.   The research was funded by Horticulture Innovation Australia Limited (HIA) from vegetable R&D levies and funds from the Australian Government.

Their findings were released recently – Manipulation of regulatory microRNAs to suppress insecticide resistance in diamondback moth. It’s complex stuff but here are a few key points;

  • the way in which the DBM develops resistance is through metabolic detoxification
  • the project explored the effect of insecticide resistance and insecticide exposure on the microRNA profile of DBM larvae – microRNAs are small ribonucleic acids that play significant roles in various physiological and developmental processes in all plants and animals by regulating expression of genes
  • results showed changes in the microRNA profile of Deltamethrin-resistant and Chlorantraniliprole-exposed DBM larvae
  • results also showed that one of the microRNAs (miR-2b-3p) can significantly enhance mortality in Deltamethrin-resistant DBM larvae; feeding this microRNA to the Deltamethrin-resistant DBM larvae led to increased mortality when the larvae were exposed to the insecticide, i.e., it reduced resistance
  • to move towards a practical application of the findings, researchers are using this information about the microRNA to produce genetically modified plants that contain the microRNA.

In the meantime, the best means of keeping on top of DBM is through flexible and multiple control strategies in keeping with IPM (integrated pest management) and IRM (insecticide resistance management) plans. Key to these are;

  • correct identification of DBM throughout all life cycle stages
  • regular and rigorous crop inspection and monitoring (scouting)
  • early detection
  • recognising weather conditions conducive to DBM reproduction and growth (warm, moist conditions),
  • encouraging natural predators to DBM by minimising the use of broad spectrum insecticides,
  • good farm hygiene such as ploughing in harvested crops
  • ensure use of insecticides only when required and at the correct life stage of the insect being targeted,
  • rotating between insecticide groups to minimise the risk of insecticide resistance (check out the CropLife website for more information on this).

Issue 9 of Vegenotes, a publication created by Ausveg, describes these measures in greater detail.  There are some useful websites with excellent information; check out the Queensland Government’s Department of Agriculture and Fisheries website, and Cesar.

To stay connected with BFVG and for further resources/information on events in the Wide Bay-Burnett region, go to our website or subscribe to our Fresh Pickings newsletter.

Sources:

  1. Asgari, S. (2016) Manipulation of regulatory microRNAs to suppress insecticide resistance in diamondback moth. The University of Queensland.
  2. Ausveg Limited (2008) Vegenotes Issue 9 – Diamondback Moth.
  3. Queensland Government. (2012) A-Z List of Horticultural Pests (website).

Acknowledgements: 

Funding for the VegNET National Vegetable Extension Network program is from Hort Innovation.