Wood Vinegar for Deterrence & Protection

Wood vinegar (pyroligneous acid) is the liquid condensed from the smoke when biomass is heated without oxygen. It carries hundreds of naturally occurring compounds, including acetic acid, phenols and furfural, and it has been studied worldwide against insects, mites, snails, nematodes, fungi, water moulds and bacteria. Renergi makes it in Collie, Western Australia, from sustainably sourced biomass.

This page summarises what the published research says about wood vinegar and the pests and diseases WA growers deal with most. Where a pest has its own page, follow the link for the detail. Where no published study exists, we say so, and explain why growers are trialling it anyway.

Pasture and broadacre pests

Red-legged earth mite (RLEM)

RLEM is resistant to synthetic pyrethroids and organophosphates in parts of WA, and growers are looking for ways to take pressure off their chemistry. Wood vinegar has not been tested on RLEM, but it has affected spider mites and aphids in laboratory work. Read more: red-legged earth mite and wood vinegar

Blue oat mite, bryobia mite and balaustium mite

These earth mites are often mistaken for RLEM but tolerate rates that control it, which is a common reason mite sprays fail in cereals, canola, lupins and pasture. No published study has tested wood vinegar on them. The rationale is the same as for other soft-bodied mites: pyroligneous acid caused knock-down and mortality in two-spotted mite in laboratory work, and its smoke odour may deter feeding on seedlings. Get mites identified before choosing a control.

Lucerne flea

Lucerne flea is a springtail, not a flea, and synthetic pyrethroids do not control it. Wood vinegar has not been tested on it. The interest is in contact with acids and phenols at the damp soil surface where it lives and feeds. Read more: lucerne flea and wood vinegar

African black beetle

African black beetle lives in the soil, out of reach of most sprays. Wood vinegar has not been tested on it, but it has shown toxic and repellent effects on another soil insect, the termite, in published work. Read more: African black beetle and wood vinegar

Vegetable weevil, garden weevil and Fuller’s rose weevil

Published weevil research on wood vinegar comes from stored grain, where it repelled 98% of rice weevils in a 2023 laboratory study. The weevils that attack WA canola, vines and citrus have not been tested. Read more: weevils and wood vinegar

Aphids (green peach, cabbage and Russian wheat aphid)

Green peach aphid spreads turnip yellows virus in canola and resists several insecticide groups, cabbage aphid colonises flowering canola, and Russian wheat aphid has been in WA cereals since 2020. A UK laboratory study exposed green peach aphid to pyroligneous acid and recorded knock-down and mortality within 48 hours. The effect was partial, so wood vinegar fits alongside a spray program and does not replace it. The activity is attributed to acetic acid and phenols acting on the aphid’s soft body.

Diamondback moth, native budworm, cutworm and webworm

Diamondback moth is one of the most insecticide-resistant pests facing WA canola and brassica growers, and native budworm flies into lupins, canola and pulses every spring. Wood vinegar has not been tested on either. A recent review cites laboratory work in which pyrolysis liquids were toxic to cabbage looper caterpillars, and a wood vinegar and neem oil mix reduced armyworm numbers. Its smoke volatiles may also mask the plant odours moths use to choose where to lay eggs.

Slaters, earwigs, Portuguese millipedes and bronzed field beetle

Stubble retention has made these regular establishment pests in WA canola, especially on the south coast. They shelter under stubble, feed at night and find food by smell, and few insecticides are registered for them. Wood vinegar has not been tested on them. It is a strongly scented liquid that has repelled snails and termites in published trials, and the idea worth testing is making the seed row smell wrong while seedlings are vulnerable.

Snails and slugs

Snails are the best-studied pest target for wood vinegar. Finnish research found it clearly repellent to snails, with acetic acid and furfural among the active compounds. The effect is repellent, not lethal, so it suits barriers and borders alongside baiting. Read more: snails, slugs and wood vinegar

Horticulture, vineyard and garden pests

Two-spotted mite (red spider mite)

Two-spotted mite bronzes and webs strawberries, tomatoes, cucurbits, vines and nursery stock in hot, dry WA summers, and miticide resistance is widespread. A UK laboratory study recorded knock-down and mortality in two-spotted mite within 48 hours of exposure to pyroligneous acid. The effect was partial and will vary with product and rate, so treat wood vinegar as a program partner and not a stand-alone miticide.

Whitefly and thrips

Silverleaf whitefly, greenhouse whitefly and western flower thrips hide under leaves and in flowers, breed fast and resist many insecticides. We have not found a published study testing wood vinegar on either. Both are small, soft-bodied sap feeders like the aphids and mites that pyroligneous acid affected in laboratory work, and both find hosts partly by smell. Protected cropping is the easiest place to test it: one treated bay, one untreated, sticky traps in both.

Tomato potato psyllid (TPP)

TPP was first found in Perth in 2017 and is now established in WA tomato, potato, capsicum and chilli crops. It has not been tested with wood vinegar. Finnish researchers reported that wood vinegar repelled the carrot psyllid, a member of the same family, and psyllids find host plants by odour. This is a rationale from a related species, not proof on TPP.

Mealybug and scale

Longtailed mealybug in vines and citrus, red scale in citrus and black scale in olives all shelter under a waxy coating that sheds sprays. A Thai study cited in recent reviews reported that wood vinegar controlled striped mealybug, and its acids and phenols are thought to help penetrate the wax. The species found in WA vineyards and orchards have not been tested.

Stable fly and fungus gnats

Stable fly breeds in rotting vegetable residue on the Swan Coastal Plain, and fungus gnats breed in wet potting media and chew seedling roots. Neither has been tested with wood vinegar. Laboratory work on the related housefly, cited in published reviews, reported effective control. The idea is that acidic, strongly scented wood vinegar makes residue or media less attractive for egg laying. It does not replace the residue management that WA’s stable fly regulations require.

Termites

Subterranean termites hollow out fruit trees, vines, trellis posts and garden timber, and they are among the most-studied wood vinegar targets. Japanese research found wood vinegar and several of its components were termiticidal, and a later study recorded 100% mortality of two subterranean termite species at 5 to 10% concentration, with a repellent effect at 10%. One was a Coptotermes, the genus of WA’s main pest termite. These are laboratory results, and they relate to trees and timber, not the protection of buildings.

Root-knot nematode

Root-knot nematodes gall and fork carrots, tomatoes, potatoes, strawberries and vines in WA’s warm sandy soils. In a 2024 Italian field study, wood vinegar applied at 1% reduced root-knot nematode infection in strawberry by 15%. A modest result, but a field one. Wood vinegar also naturally contains furfural, a compound registered overseas as a nematicide.

Root lesion nematode (Pratylenchus)

Root lesion nematodes are common in WA cropping paddocks and take yield from wheat, barley and canola, with no in-crop treatment available. Wood vinegar has not been tested on them. The rationale comes from the root-knot nematode field result, the furfural content, and wood vinegar’s use to stimulate root growth, since a bigger root system tolerates more nematode pruning.

Seeing one of these pests? Ask us for the research and suggested rates, or buy Renergi Wood Vinegar online.

Fungal and water mould diseases

Powdery mildew

Powdery mildew grows on the outside of the leaf, where it is exposed to whatever is sprayed there. Wood vinegar’s phenols have inhibited a wide range of plant disease fungi, and it has been shown to raise plants’ own defence enzyme activity. Trial work on powdery mildew itself is still thin. Read more: powdery mildew and wood vinegar

Phytophthora root rot and dieback

Phytophthora is a water mould, and wood vinegar has repeatedly inhibited water moulds in the laboratory, including several Phytophthora species. Phytophthora cinnamomi itself has not been tested. Read more: Phytophthora and wood vinegar

Pythium, damping-off and cavity spot

Pythium is one of the best-documented wood vinegar targets, with strong laboratory results and reduced disease in greenhouse cucumber at 0.125%. Read more: Pythium and wood vinegar

Downy mildew

Downy mildew hits WA grapevines in wet springs, canola seedlings in damp starts, and irrigated onions, lettuce and cucurbits. In a two-year field study on canola, foliar treatments based on wood vinegar reduced downy mildew incidence by about 12% in the best treatment, and wood vinegar diluted 400 times lifted seed yield by an average of 9.6%. Laboratory work cited in reviews also reports inhibition of grapevine downy mildew.

Flag smut, loose smut and bunt

Wood vinegar has not been tested on flag smut. European organic research found that acetic acid, wood vinegar’s main organic acid, controlled common bunt in wheat as a seed treatment. Read more: flag smut, bunt and wood vinegar

Rhizoctonia bare patch

Rhizoctonia bare patch is one of the costliest root diseases in WA cereals, worst on sandy soils and in no-till systems after a dry start. Wood vinegar inhibited Rhizoctonia solani in the laboratory and reduced Rhizoctonia disease in greenhouse cucumber at 0.25%. The cereal strain has not been tested in the field. Rhizoctonia is suppressed in biologically active soils, which is why soil biology is part of the interest.

Fusarium crown rot, head blight and wilt

Fusarium has some of the strongest wood vinegar data: a 66% cut in head blight infection in Chinese field work, and an 81 to 100% reduction in tomato Fusarium wilt in a 2024 greenhouse study. Read more: Fusarium and wood vinegar

Sclerotinia stem rot

Sclerotinia is a major disease of WA canola and lupins in medium and high rainfall zones, and causes lettuce drop and white mould in vegetables. In the same two-year canola field study, foliar treatments based on wood vinegar reduced Sclerotinia incidence by about 17% in the best treatment, alongside the yield gain. Laboratory work also shows wood vinegar inhibits Sclerotinia sclerotiorum.

Botrytis bunch rot and grey mould

A 2025 grapevine study found wood vinegar at 2% and 4% inhibited Botrytis and reduced lesion length on inoculated vine tissue, while lifting the vine’s protective compounds. Read more: Botrytis and wood vinegar

Anthracnose (lupins, avocado, mango and olives)

Anthracnose bends and breaks lupin stems and rots avocados, mangoes and olives, often after harvest. A 2024 review reports that wood vinegar’s inhibition of Colletotrichum gloeosporioides, the avocado and mango anthracnose fungus, was similar to the fungicide chlorothalonil. Other studies report activity against two more Colletotrichum species. Lupin anthracnose has not been tested.

Alternaria leaf spot and early blight

Alternaria causes early blight in potatoes and tomatoes and leaf spots in brassicas, carrots and apples. In Korean research, pyroligneous acid completely inhibited Alternaria mali, the apple leaf blotch fungus, at a 1:32 dilution, and soil-applied wood vinegar indirectly reduced tomato early blight by building beneficial soil microbes.

Blackleg, septoria, yellow spot, net blotch and rusts

These stubble-borne diseases are the ones WA broadacre growers budget fungicide for every year, and resistance is established in several. None has been tested with wood vinegar. Related evidence exists: it inhibited the cereal pathogens Fusarium graminearum and Cochliobolus sativus in laboratory studies cited in reviews, and it has been shown to raise plant defence enzyme activity.

Take-all

Take-all blackens the roots of wheat and barley in the high-rainfall south, and no in-crop fungicide fixes it. Wood vinegar has not been tested on it. It has inhibited other soil-borne root fungi in laboratory and greenhouse studies, and Chinese research cited in a 2024 review found it raised soil enzyme activity and improved wheat’s resistance to root rot.

Grapevine trunk disease (Eutypa and Botryosphaeria)

Botryosphaeria and Eutypa dieback infect through pruning wounds and rot vines from the inside. Wood vinegar’s longest research record is against wood fungi: it inhibited white rot and brown rot fungi at 0.5 to 2%. The trunk disease fungi themselves, and use on pruning wounds, have not been tested.

Dollar spot, brown patch and Pythium in turf

Dollar spot, brown patch and Pythium mark greens, fairways and ovals across WA. Wood vinegar has not been tested on turf. Two of the main turf pathogens are covered in the laboratory: Rhizoctonia solani, the cause of brown patch, and Pythium. Dollar spot has not been tested.

Bacterial diseases

Bacterial spot, canker, black rot, soft rot and crown gall

Bacterial diseases leave growers with copper, hygiene and clean planting material. In the laboratory, wood vinegar inhibited Xanthomonas campestris and Agrobacterium tumefaciens, the crown gall bacterium, at 10% dilution, and a 2025 study found three wood vinegars inhibited the soft rot bacterium and a Pseudomonas syringae pathogen. Field data is limited.

Weeds

Non-selective weed control

At high rates, wood vinegar is a documented contact herbicide. Finnish field research found it destroyed virtually all above-ground growth of broadleaf weeds at 400 to 1,300 L/ha, with couch grass the main survivor. It does not move through the plant, so perennials regrow. Renergi Wood Vinegar is made to be gentle on plants – at normal dilutions it is not herbicidal – so burn-down takes high volumes of undiluted product and suits spot spraying, paths, under-vine strips, and better accompanying other products to improve their efficiency. 

Rates, research and trials

Tell us your crop and the problem, and we’ll send you the research and the rates other WA growers are using. If you want to test it properly, we’ll help you set up treated and untreated strips. Contact us, or order Renergi Wood Vinegar online in packs from 4 litres up to 1,000-litre IBCs.

Renergi Wood Vinegar is supplied as a soil and plant conditioner. The research summarised on this page is published third-party work.