Leaders in Sustainable Horticultural Excellence

Future Pathways for Sustainable Horticulture

Innovating Land Management Strategies for NAP Growers

Sustainable Industry Grants 2014-15

Discussion Topics

• What is a nematode

• PreDicta DNA and sampling test

• Nematode Control• Fumigator Sorghum

• Perlka Fertiliser

• Nematode Control Trials – Field & Greenhouse Crops

• Trial Takeaways

• Hygiene

• Future work

What is a Nematode

• Nematodes - microscopic worms that move between soil particles and on plant material. They spread on your farm through water, soil, boots and dirt machinery.

• Nematodes pierce the cell walls of plants and ingest contents. The nematodes stylet releases enzymes that break down the cells within the plant. This causes the following visual symptoms often seen by a grower

Typical nematode symptoms

Typical nematode symptoms

Typical nematode symptoms

Nematode testing and Why?

• Nematode testing is rarely performed before applying a treatment • Two methods – Visual counts and now DNA

• Often we apply and pray it works• Often leading to malpractice

• Why treat if you don’t know what your problem is?• You may not have nematodes, the species may not be a host to your crop

PreDicta Test

• DNA-based soil testing service that identifies which soil-borne pathogens pose a significant risk to broadacre crops and Potatoes prior to seeding

• HortEx are adapting the PreDicta Pt test to be used in other Hort. Systems

• The test picks up specific organisms and picks up everything of the Organism. • It then quantifies the total amount • Right down to species level

• DNA can test for many pathogen at once

PreDicta Test

• It doesn’t predict disease but is a quantification of a nematode level. • High level of a pest not a prediction you will get disease.

• Treat the test as a risk analysis.• Focus on things likely to be a problem

• Type of nematode, crop planting

• Can use it to identify levels and try and get them as low as possible

• If you know your pest you can treat it accordingly • save you money on input costs • targeting the right application to the pest

Taking soil for the test• An auger is useful for taking many sub-samples (cores) while reducing the total

amount of soil collected.

• A spade can be used, but remove the soil with your hand from along the vertical edge of the blade, spades are useful for collecting roots and associated, relatively undisturbed soil.

• Soil max limit 500g.

• Clean your tools before sampling a separate plot or field.

• Nematodes are most abundant within the root zone and, for shallow-rooted crops, samples can be taken to a depth of about 20 cm. A depth of 40 cm or more, may be needed in deep-rooted crops.

• Sub-samples should be collected in a bucket or bag and mixed while walking up and down the field. Collecting a sub-sample at regular intervals along a “W” or “zig-zag pattern

Nematode Testing

• Testing can be done through SARDI• PreDictaB (Potato DNA Test) - $192.00 ex gst

• We tested nematodes before and after fumigation with Sorghum and Perlka and 3 months later

Nematode Treatments• Fumigator Sorghum (Pacific Seeds)

• Planting Rate – 15kg per 2500m2

• Breaks down to release toxic cyanide when plant tissue is damaged

• Do not let the Sorghum go to flower as the chemical will decline and the fumigation effect decline

• It must be chopped thoroughly and incorporated quickly, or compound can be lost to the air

Plant your seed and let it germinate Let it grow to ≈ 1m

Slash it

Let it re-grow ≈ 100 mm then re-slashHoe it in to release the fumigant

Field Crops – Fumigator Sorghum

Seedlings 7 days after sowing Growth 3 weeks after sowing

Greenhouse – Fumigator Sorghum

Nematode Treatments

• Perlka• Application Rate - 1000kg/ha

• Addition to Soils – Carbon , Calcium and Nitrogen

• Plant back period – 2 days for every 100kg/ha of Perlka

• No gas released. Needs to be watered in to fumigate

• Gives calcium cyan-amide that effects the Nematodes

Field Crops - Perlka

1000 kg/ha Perlka Perlka Weed Control

Greenhouse – Perlka / Eggplant

Greenhouse results

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Sorghum Tomato Pre Sorghum Tomato Post Sorghum Tomato 3 month

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Nematodes found Pre, post and 3 months after Perlka application in eggplants

Perlka Eggplant Pre Perlka Eggplant Post Perlka Eggplant 3 month

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Eggplant Pre Eggplant Post Eggplant 3 month

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Nematodes pre and post Sorghum then Telone in Cucumber

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Nematodes pre and post Sorgum then Telone in Cucumber

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Pre Capsicum Sorghum after Sorghum

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Pre Capsicum Sorghum after Sorghum

Field results

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nematodes /g soil

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Pre Cabbage Post Cabbage 3 m after perlka Cabbage

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Nematodes pre, post and 3 months after Sorghum application in Cauliflower

Pre Cauliflower Post Cabbage 3 m after barley Cauliflower

Rhizoctonia

• Fungal disease affecting a wide range of crops

• Most likely to be a severe problem where the plant is under stress from factors other than the disease, for example, low rainfall or poor nutrition

• Good nitrogen nutrition helps to minimise the effects of the disease. Maintaining adequate nutrition (especially nitrogen) during crop establishment is the best way to reduce the chance of Rhizoctoniainfection.

Rhizoctonia in tests

• Ag 2.1 and 4 was in nearly every crop tested. • Ag 2.1 has a wide host range but not generally an issue in crops

• Ag 4 is normally in Brassica, weeds and this could be a reason why this was shown in the results

• Rhizoctonia will also survive on Sorghum

• Nematodes and Rhizoctonia can interact

• Only 1 grower tested has no Rhizo and has an intensive compost program

Trial takeaways

• Overtime particularly in the greenhouses Nematodes build back up• Commercial crop expect them to come back. They have multiple life cycles

and in warm conditions will increase fast so it’s helps complete their life cycle • Some Nematode species can go deep into the soil and could come back from

down deep in the soil structure • Other controls through the life of the crop eg Biologicals?

• Treatments very unlikely to kill every nematode. • The key is to get to a level below risk threshold or as close to zero as possible.

• Sampling is key, particularly in open fields

Trial takeaways

• The tests are quantifying that there are key nematodes for various crops • Meloidogyne sp in greenhouses • Pratylenchus sp in field crops

• Further tests have highlighted that Nematodes are a major problem • Many growers are in the 3 to 4000 units / g of soil, particularly in greenhouses. One grower

up to 33,000

• Use test helps know is in your soil • HortEx are using treatments to try get Nematodes to manageable levels.

• Incorporating Organic matter increases mico-organsims that will reduce soil borne plant pathogens – both Rhizo and Nematodes.

Hygiene

• If Nematodes can build back use Hygiene• Foot baths, booties

• Cleaning down picking trolley

• Cleaning spray hose

Future work

• We are currently investigating the use of Telone• Stacking treatments eg Perlka and Telone

• Brassica fumigation

• Biological treatments

• Further work with SARDI we are hoping to develop threshholds for various crops in the near future

Thanks for attending