Bushfire Aftermath / Weeds

It seems the fire ground, with a bit of rain, has turned into a weed jungle.

Tens of thousands of seeds must have lain dormant for years under the pasture and now, with a bit of moisture, warm weather, no competition from the grass and the richer ash laden post fire soil, have taken off. 

There are about eight different types, four of which I have never seen in this area before.

One of concern is the thorn apple. It is toxic to stock (and humans) and needs to be gotten rid off before winter reduces pasture growth and the cattle start getting interested in alternative feed.

Thorn Apple

So this means back pack spraying with glyphosate ie. Roundup or it’s equivalent.

Since Monsanto’s patent ran out in 2000 many new and much cheaper brands came onto the market.

We normally use a Chinese product.

This chemical is a little controversial and is in the midst of a few court cases around the world and its use is being cut back. There is also a resistance problem developing.

My old company bought Monsanto a few years ago and are now maybe regretting inheriting a bit of a poison chalice.

But I have used glyphosate for decades. It is a very effective product. Whether it has affected me health wise remains to be seen. I think I was in much more danger during my business career working in industries which at the time had little or no protocols for chemical exposure and worker safety.

Glyphosate molecule 

The chemical usually diluted to 10-15 mL/ L in water is absorbed through foliage and minimally through roots and is transported to growing points ie. a systematic herbicide.

It inhibits a plant enzyme involved in the synthesis of three aromatic amino acids: tyrosine, tryptophan, and phenylalanine, all essential for growth, causing the plant to die and eventually desiccate. While growth stops within hours of application, it takes several days for the plant to show signs of a successful ‘kill’. We have found the some species eg. blackberry and tussock can take weeks to yellow, while others eg. thistles take two days. It also depends on the stage of plant growth related to its environment. Low temperatures and dry soils can slow down the chemical’s action.

So it will be a few long days attacking this unexpected problem but the autumn weather is nice to work in ie. sunny but cool and with the Covid ‘stay at home’ rules in place there is not much else to do.