Wandering jew or trad (Tradescantia fluminensis, syn. T. albiflora) Environmental foe or Chicken delight?

The waterways in South Gippsland are well aquatinted with this weed from South America.  It loves nothing better than shady spot down by the river where it thrives on silty alluvial soils.  It's not a huge fan of being submerged in water but it does tolerate the occasional flood and will put up with being waterlogged ever now and again.

Wandering trad has hairless leaves which are glossy, slightly fleshy and dark green in colour. A distinctive feature of the plant is its stem-clasping leaves at the base. Flowers are white, about 1cm across displayed during spring and summer. Fruit is not formed on the plant in Australia therefore it does not spread by seed but rather by broken off sections of stem taking root.

As the name suggests, it wanders about and forms dense mats that smothers all native groundcover vegetation in its path. Subsequently preventing natural regeneration of trees and shrubs. Over time, (in a stream bank situation) this process causes eventual loss of native tree and shrub cover which can lead to erosion.  This makes wandering trad an unpopular addition to the natural environment in Australia. 

In terms of its control, there are several options (see below). Using a combination of these, (based on site specifics and resources at hand) is the best method.

Manual removal: small infestations can be dug out ensuring that all stem fragments are removed, (if not they will regrow) and disposed of appropriately. 

Solarisation: covering the plants with plastic sheeting for 6 weeks in the warmer months will weaken the plant (sunny situations only, this will not be effective in full shade). After removing the plastic any regrowth can be dug out or sprayed.

Herbicide: spraying with selective or non-selective herbicides, (using a surfactant) will work eventually but repeat treatments will be required. Herbicides registered in Victoria for use on wandering trad can be found on the APVMA website; www.apvma.gov.au.  

Alternative uses: Julie Cave, Blue Mountains City Council Bush Regeneration Team member has made some suggestions for the use of trad which include; turning the plant into liquid fertiliser or compost. Read more on this by visiting http://www.weedsbluemountains.org.au/index.php.

Whilst researching control methods for wandering trad I came across findings that suggest ducks and chickens love the stuff. Apparently Muscovies and chickens consume wandering trad readily with no ill effects (given that the plants have not been sprayed with herbicide). If someone works out how to drive a flock of ducks down to an infested gully for some crash grazing we might have another viable management tool. In a domestic situation, those with chooks (and wondering trad) may have themselves a cheap and useful solution to the problem.

For further information on the identification of wandering trad visit www.southgippslandweeds.com.au or contact Kate Williams, South Gippsland Landcare Project Officer on (03) 5662 5759 or email katew@wgcma.vic.gov.au. Information from this article taken from Wandering jew (Tradescantia fluminensis, sny. T. albiflora)  http://www.esc.nsw.gov.au/site/Weeds/Sheets/herbs/H%20Wandering%20jew.htm, Eurobodella Shire Council, NSW.

Kate

African lovegrass

No love for African Lovegrass (Erogrostis curvula)

 

African lovegrass, or 'ALG' as it's referred to by those who know it,  is a major weed of grazing land throughout mainland Australia. South Gippsland's not immune to invasion by African lovegrass. There has been a recent report of isolated plants as close as 10km from the South Gippsland Shire boundary; it may very well be within the Shire boundary.  Being a tussock grass, its presence is often overlooked; (unlike weeds with bright purple flowers that are easy to spot) it can also be confused with some other native or introduced grasses. Early detection allows early control. What to look for;

·        Perennial tussock grass (forms as a clump)

·        Grows from 30-70cm high with a diameter of 25-35cm at ground level

·        Begins flowering in spring or early summer with erect, open or compact seed heads that are a lead-grey or grey green colour  (see photo below showing the seed heads)

·        Leaves are blue-green, long and narrow with curly tips

·        Has a ring of hairs below the base of the leaf blade

Whilst is can be confused with some native and introduced species, it is clearly distinct from them;

·        Spear and corkscrew grass (Austrostipa sp.) look similar to African lovegrass in the early vegetative growth but have awns on the seed.

·        Other native and introduced lovegrasses often look similar but have different seed heads.

African lovegrass is a problem in an agricultural situation as readily establishes in overgrazed pastures and only produces a limited quantity of green feed during the spring and summer months. Overall carrying capacity is reduced where infestations are dense. Forage quality declines as the plants mature and also with the commencement of frosts. The amount of green leaf dry matter utilised by the animal is at best 65% in early spring and 50% in early summer. Come winter, the amount utilised by the dead material is only 38%. Crude protein of the dead leaf in winter is only 3.6%.  Minimise the risk of seed entry and establishment on your property by paying attention to likely sources of seed import. The movement of fodder is a main cause of weed seed spread in agriculture. If you're looking to purchase hay or livestock from a known African lovegrass area (check with Bob Wilson, DPI Gippsland Coordinator Pest Management to find out general distribution on T: (03) 56 629 930). Supplementary feeding in a smaller 'sacrifice' paddock is a good precautionary measure followed by monitoring.  Be conscious of livestock movements, seeds take up to 7-10 days to pass through livestock and can still be viable for 10 days, as with the fodder keep livestock in a smaller paddock and monitor.

For further information on the identification of African lovegrass contact Kate Williams, South Gippsland Landcare Project Officer on (03) 5662 5759 or email katew@wgcma.vic.gov.au. To find out the general distribution of African lovegrass in Gippsland contact Bob Wilson, DPI Gippsland Coordinator Pest Management on T: (03) 56 629 930). Information from this article taken from Primefacts, February 2010 Edition via www.industry.nsw.gov.au and African lovegrass, May 2009. 3D weed management, Meat & Livestock Australia, Sydney.

Photos of African lovegrass courtesy of Peter Kershaw, VicRoads Eastern Region 2011.

Broadleaf Dock

A recent visit to a farm, (that rears dairy calves) in South Gippsland has prompted me to talk about dock. Several paddocks on the farm were thick with broadleaf dock (Rumex obtusifolius), whilst out on a paddock the farmer asked "why is it growing with such vigour?" and "How can I get it under control without relying on herbicide?"

 

To address the first question one needs to try and understand what that plant is telling us. Docks are a perennial herb with a thick taproot. Plants with taproots are typically found in areas of poor drainage- the plant is trying to correct this problem by penetrating deep into the subsoil to improve drainage and aeration. Why might drainage be poor you ask- In pastures, calcium is a mineral removed in great quantities with the least return in the manure. Calcium is the element which, among other things, causes soil particles to move apart for good aeration and drainage. Soils deficient in calcium are in effect prone to water logging. Therefore even before doing a soil assessment or test we can assume that calcium may be deficient and that drainage is poor. High stocking rates may be another factor for compaction and subsequent poor drainage however the farmer indicated that stocking rates were fairly low and that they haven't even been stocked recently given the amount of water on the place.

Delving deeper, (quite literally!) a soil core sample was taken so that a quick visual assessment of the soils biotic and physical qualities could be made. It was obvious from the sample taken that the soil lacked diversity of microfauna with only earth worms present. A cockchafer grub was also found in the sample. Cockchafers are common pasture pests in Gippsland, affecting shallow rooted pasture species, having minimal impact on deep-rooted plants such as lucerne, cocksfoot, phalaris and dock for that matter. The extent and severity of damage caused by cockchafers varies markedly from year to year and from one property to the next. The main indicators of their presence can be found during a dry spell after the autumn break, when dead pasture is found among areas of green. Dead pasture, unless re-sowed, provides a perfect home for a new dock plant or another broadleaf plant such as capeweed. Perhaps this is another factor contributing to the growth of dock throughout the paddock. Looking at the grass in the sample, (namely the roots) it's clear that they are confined to the top few cm's of soil- yet another indicator that oxygen is poor lower down.

Following the visual assessment a *soil test was taken for chemical analysis. Results of the test found that, as suspected, the available calcium was slightly low. It also revealed that the available potash exceeded the available phosphate- this is characteristic of soil favoured by broadleaf weeds. Available nitrogen was low, (6.1ppm, desired level=26ppm). Nitrogen is the one nutrient that can be hard to manage as it's readily lost through leaching. Soil bacteria play a critical role in converting the nitrogen into amino acids- in this form it is not likely to leach.  The soil test didn't test for the present of soil bacteria yet if it did there would be affair chance they would be in insufficient numbers.

With all the above in mind – finding an answer to the second question can seem overwhelming! I'm not an agronomist- and I don't intent to give specific advice as such- rather I've put together a list of useful resources below that can help you build a picture of ways to correct your specific weed problems.

Remember- you can spray pasture weeds with herbicide until the cows come home yet correcting the health of the soil should be the aim of the game.

McCaman J.L. 1994. Weeds and Why They Grow. Acres Australia www.acresaustralia.com.au

 Department of Primary Industries, Victoria information on soil relevant to agriculture; http://new.dpi.vic.gov.au/agriculture/farming-management/soil-water

Department of Primary Industries, Victoria information on the Red headed cockchafer

http://new.dpi.vic.gov.au/agriculture/pests-diseases-and-weeds/pest-insects/ag1358-the-redheaded-pasture-cockchafer

Primary Industries, NSW information on fertilisers and soil improvement http://www.dpi.nsw.gov.au/agriculture/resources/soils/improvement

*It should be said that a plant tissue test is the preferred method for diagnosing trace element status of a pasture rather than a soil test but for the purposes of this exercise a soil test was taken.

Bridal Creeper: Be part of a program to reduce its spread!

Bridal creeper (Asparagus asparagoides) is a perennial climber growing to 3m tall with a tuberous root system growing rapidly in autumn/winter (NOW) dying back to the roots over summer.  The glossy leaves are a distinct bright green colour and 3cm long. Flowers are small and greenish to white hanging on stalks singly or in pairs along branchlets. Fruits are small red berries, 6-10 mm in diameter with up to 9 black, shiny seeds within when ripe.  Bridal creeper is a Weed of National Significance as it readily invades disturbed and undisturbed vegetation across a wide range of habitats.

Left uncontrolled, it can have significant impacts to natural ecosystems. The plant can dominate ground flora forming dense curtains that smother shrubs and the lower canopy of trees. Bridal creeper is not considered an agricultural weed as it is palatable to stock and reproduction is greatly inhibited by herbivores. Bridal creeper has a number of features which make it difficult to control – its tuber reserves provide a buffer against adverse seasons, it has a wide germination range and, as mentioned above, it can invade undisturbed areas. On the up side - bridal creeper has a short-lived seedbank and seed production only occurs in early emerging stems.

With this in mind, preventing invasion in the first place and being vigilant in controlling new outbreaks really is the best line of defence. Typically new outbreaks occur underneath tall trees where seeds have been spread by birds, monitor these areas for potential outbreaks. All underground tubers need to be removed in order for manual removal to be fully effective. Tubers can grow at some depth under the soil therefore using a small mattock to get leverage is the best way to go.  All removed material should be double bagged and disposed of appropriately.  Removed tubers have been shown to survive even with out light for 2 years- therefore correct disposal is important.

If you have noticed Bridal creeper on your property, please contact Kate Williams, Landcare Project Officer at the South Gippsland Landcare Network on (03) 5662 5759 or email katew@wgcma.vic.gov.au.  The Network is managing a control project along the Gippsland coast from Phillip Island to Port Albert, (where it is known to exist) in partnership with a range of stakeholders and financial assistance is available until July this year. This project is supported by Coastcare Victoria Community Grants- a joint program delivered in partnership between the Australian Government's Caring for Our Country and the Department of Sustainability and Environments Coast Action/Coastcare program.