A recent trip through the Pilbara showed widespread establishment of buffel grass (Cenchrus ciliaris). It was looking impressive on many properties following substantial rain across the region in May.  While the presence of a palatable perennial grass is good news for graziers it is a major problem for anyone managing native vegetation areas in National Parks and Nature reserves.

Buffel grass changes the ecology of the area. While we tend to think in easily visible species such as kangaroos and wallabies which no doubt also find buffel grass good tucker. On the other hand there are small marsupials, rodents, reptiles and other animals we rarely see that find their environment vastly changed, often to the negative.

Probably the best stand was in the Cape Ranges National Park near Exmouth where it was 70 to 90 per cent ground cover.

Distribution of buffel grass in Australia. Source:Australian Virtual Herbarium

Another issue that was obvious on our travels was that many properties had very little ground cover or feed, despite heavy rain 4 weeks before. It would be reasonable to assume that most of the water ran off without entering the soil due to the lack of ground cover. The image below shows how little soil cover there was despite reasonable recent rains.

Grazing exclusion zone (background) showing potential groundcover versus actual groundcover (foreground).

For more information on buffel grass go to:

http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0005/347153/awmg_buffel-grass.pdf

There has been a lot of talk and promotion of harvest weed seed management to keep a lid on cropping weed numbers and when done properly it does work. Unfortunately it is human nature to hear the pieces of a message that appeals to us and we don’t give heed to the full story.

The burning of narrow windrows appears to fall into this category. Recently there have been some runaway fires which have damaged fences, stubble cover, dry pastures, remnant native bushland amongst other things. Luckily no one was injured or killed and livestock losses were also low. These incidents lead to difficult relations with neighbours and incur added costs and lost opportunities.

Stubble burnt from escaped burn. Loss of groundcover will create crop establishment problems with possible loss of crop yield.Sally Peltzer from the Department of Agriculture & Food WA has just put out a timely reminder in the latest edition of e-Weed of the do’s and don’ts of successful windrow burning.

Using the McArthur Fire Index, or if you are a hipster with an iPhone, the Pocketfire® app, are good places to start to tell you the conditions are suitable to get a good burn that kills weed seeds but can still be contained. Look at three and 10 day weather forecasts to get an idea of likely wind directions and speeds.

Remember basic fire safety. Never light fires alone and without fire fighting gear primed and ready.

Light the rows every 50 to 75 m depending on the conditions. Light into the breeze or have a cross breeze. Don’t light the up wind side and hope for the best.

Normally there is about a 3 hour optimum time every day to burn narrow windrows and aim to have them out by 10 pm. Check again next morning to put out any smouldering patches.

Burnt dry pasture could mean the need to hand feeding in a dry autumn and winter.

It is always interesting, for me at least, to have a close look at the vegetation when travelling, both around Australia and overseas. Guess it is my love of nature and the environment, plus living life as a scientist .

Last month I was working in northern South Africa for two weeks, then across to Botswana for two weeks of Safari.  This was our first time doing Safari and I will have to admit it was fantastic. Botswana has tourism down to a fine art and I highly recommend it as a safe and great destination. However I digress.Area of Botswana where we "safaried".

Between observing a fantastic variety African wildlife in their natural habitat I observed some very familiar plants. Both Australia and southern Africa have been busy exchanging native species that then become weeds in their adopted home.

The first was feathertop Rhodes grass (Chloris virgata) at Nxai Pan, which is becoming a major weed in northern New South Wales and Queensland. This was a minor part of the lush vegetation which would soon dry off and be eaten down to dust by the vast numbers of grazers who traverse the landscape.  It is interesting to note that one of its many common names in southern Africa is ‘Old land grass’, and it tend s to be found on heavily croChloris virgata at Nxai Pan.pped areas.

Some of the grazers at Nxai Pan.Next was a species of fleabane out in the wilds of the Okavango Delta. The area with the fleabane was soon to go underwater with the coming annual flood.  The plants looked like either Tall fleabane or Canadian fleabane, however the University of Pretoria’s Plant Science Herbarium lists 12 species. I know enough about plant taxonomy to know when I am beaten. Going down to species should often be left to the experts, and let them argue among themselves.Fleabane waiting for the Delta flood.

Flaxleaf fleabane is also major problem in horticulture in South Africa’s Western Cape, with populations resistant to both glyphosate and paraquat. So it isn’t just us having trouble with this species.

From my back of the drum calculations, the proportion of farmers regularly testing for herbicide resistance would have to be 10 per cent at most. Many will do it as a "one-off" but this really isn't good enough for managing herbicide resistance.

One of the main reasons there is a low usage of testing is because it was sold as a “you have resistance-you don’t have resistance” tool, which doesn’t tell the farmer much about management decisions needed to be taken.

A test for trifluralin resistance in annual ryegrass. An eye-opener. (image:P. Boutsalis)To be fair, this was reasonable when resistance was rare. Now it is widespread with many weeds resistant to many modes-of-action farmers need more.

Resistance testing must be seen as a positive management tool to give farmers the knowledge of what herbicides are still effective in each paddock. Regularly testing will enable better weed control and save money. Now who could ask for more than that?

Now which herbicides will control this ryegrass?The link below is an interview with Peter Boutsalis, ‘father’ of the Quick-test® where he outlines the major benefits of regular testing.