Sciencemadness Discussion Board

Herbicides, substitutes anyone?

BromicAcid - 26-7-2004 at 17:48

At my work we have to constantly use herbicides to kill the vacant areas of land that we have, otherwise we have to mow it and weed whip it, obviously that takes a whole lot more time then just spraying it.

Problem is most sprays that we use kill the plants for what seems a short while, two or three weeks, then we have all new weeds taking over the land. We have a 45 gallon sprayer (170 L) that we use.

Another problem that I have is all weed killers are different. I'll have to look at the ingredients at work, but out of the five bottles of different weed killers we had laying around today, no two of them had the same active ingredient. And the bases are different too, some are water, but one was 35% kerosene and 60% aromatic hydrocarbons, when added to water that one forms a white emulsion, interesting.

Nonetheless, does anyone know of a good chemical that might be a decent herbicide that could be available online concentrated from a chem supplier? I don't want to lay waste to the land forever, whenever a person moves into the property they lay down sod and that takes up host in the land, so no salting the earth here.

Currently five treatments cost us $670 on the upper end, and $350 on the lower end depending on which herbicide we use.

Magpie - 26-7-2004 at 18:21

This is one of my hot buttons - i.e., the seemingly overuse of herbicides and pesticides. The only one I will use on my yard is a systemic for roses, and I don't even like applying that. I just have a tremendous respect for the effect of complex organic chemicals on the biosphere. I've taken enough hazardous waste training courses that I believe most of these potent chemicals are mutagens or teratogens either for people or other innocent creatures. I either pull the weed by hand, mow it, or ignore it. I would hate to think that I or someone in my family got cancer because I took the easy way out for weed control.

Don't take this personally. You are getting paid to do a job that someone, if not you, will surely do. The herbicide that seems to be most popular around here is Roundup.

chemoleo - 26-7-2004 at 18:57

Well, a very good weed killer or rather, plant killler is NaClO3, sodium chlorate.
It is one of the most potent ones I ever witnessed - i.e. burst [that is, exploded] rockets with NaClO3 fuels would kill the plants in the surroudning areas.
Only by hearsay I heard it acts by lysing plant cells - but I yet wish to find a mechanism for that.
NaClO3 is commonly used in this country (which one is that? :P) to get rid of weeds on railway tracks.

Anyway, it's nasty stuff, I wouldn't want to eat it. Despite being an interesting oxidiser though, it has a lot of unrelated effects!

Regarding your different kind of herbicides - just post their marketing names, and lets see what we can find!

vulture - 27-7-2004 at 12:38

NaClO3 isn't that dangerous, but it washes away rapidly so it'll penetrate into ground waters quickly.

KClO3 might therefore be more effective and ecofriendly.

IvX - 29-7-2004 at 06:54

How eco-friendly can this get?Have you considered simply paving it?I will look for specifics but there are some shortish (GM) breeds of grass that could be planted there possibly taking over the weeds.

Other than that there's always mixing kerosene or anti-freeze or something like that but that may become a hazard.

chemoleo - 30-7-2004 at 05:50

Well, in principle there certainly aren't many ways for herbicides to be environmentally friendly.
There are always bound to be side effects, and using more complex weed killers (that are specific to the type of plant metabolism) may well work, but may also have detrimental effects on the surrounding biosphere.
The most biologically friendly weed killer would be a plant virus, specific to that plant - providing it wouldnt have tendency to mutate and to attack otther plants.

Vulture - to my knowledge I have never seen KClO3 being sold as weed killer. While NaClO3 certainly is. If KClO3 were more effective than NaClO3, then surely it would dominate the market, unless KClO3 is hugely more expensive to produce.
Also, I am tempted to think that the high solubility is part of the effectiveness of NaClO3 as a plant killer.
According to this reference http://www.ams.usda.gov/nop/NationalList/TAPReviews/SodiumCh... , chlorate lasts in the soil up to 6 months! - and it kills all plant growth except moss (which are evolutionarily divergent from the plants we know).
The toxicity is thought to be an effect of its oxidising capacity, and the chlorite ion that may be formed within the plant cell.

However, in this particular publication, chlorate is not praised much. Apparently it leads to increased salinity and phytotoxicity of the soil, after repeated exposure. I guess thats less of a problem if it rains a lot. However, the soil is damaged even longer if the well-known diuron is used.

Also, Bromic, have a look at http://www.uwyo.edu/plants/wyopest/TrainingManuals/Weedctrl....

It's a more detailed guide on different weeds and herbicides.

Anyway, to be honest I am not a big fan of weed killers either. As if the planet is not already suffering enough
:o

[Edited on 30-7-2004 by chemoleo]

Dodoman - 4-8-2004 at 09:48

When it comes to pests I believe in biological control. Don't be so chemically minded. First of all u need to figure out which of the 172 spieces of weed you got this could help http://web.aces.uiuc.edu/weedid/ then look for a natural enemy here http://www.nysaes.cornell.edu/ent/biocontrol/weedfeeders/wdfdrtoc.html and try introducing that enemy in the enviroment. It should work. The control agent (say a bug) would finish off the weeb then die due to lack of its host.

Cyrus - 4-8-2004 at 19:05

If only it were that simple....

IvX - 4-8-2004 at 22:21

Dodoman, atleast with (these)chemical killers you know what your dealing with and relativly simple.But (assuming it's possible)with your way there's virtualy no way of knowing what effects it will have and causes a much larger problem than just NaCLO3 since whatever you use will be signifcantly more complex.

Twospoons - 4-8-2004 at 23:20

There is a method of weed control called 'solarizing'. This involves laying a sheet of black polyethylene plastic over the ground for 2-3 weeks (maybe longer) and letting the sun cook everything under the sheet. The advantage this method has is that it can also kill dormant seeds in the top layer of soil. I'd imagine best effect would be achieved by mowing the area first (as short as possible). Obviously this method is only applicable to the hot sunny days of summer.

to chemoleo

Turel - 5-8-2004 at 00:40

about chlorate action being through lysing the cells:

The likely mechanism (very likely) is that of cellulose oxidation in the cell wall. Chlorates likely oxidize the cellulose to produce gaseous carbon monoxide and dioxide, which result in both destruction of the structural integrity of the cell wall, as well as gas pressures within the wall.

Not to mention the residual (cation) chloride byproduct, which would increase cell permeability through the cellular membrane (helping to allow internal solutions to exit the cell).

unionised - 5-8-2004 at 14:03

"First of all u need to figure out which of the 172 spieces of weed you got this could help "
I'm sure that there are more than that many weeds (I have a nasty feeling there are more than that in my garden:) ).

Anyway, the trouble with most biological controll is that you have got the weeds the local bugs don't eat. Introduce a new bug and you just shift the selection pressure to a different weed.
It's rather difficult to stop plants growing where you don't want them, an empty space is as unstable as a monoculture.

The best solution I can think of is to stop trying. Label the vacant lots as "local nature reserves, helping to maintain biodiversity". Make this part of your advertising too.
(Or get some sheep)

Magpie - 5-8-2004 at 18:18

I like the idea of letting the land revert to a natural state but recognize that doing this may cause the landowner to be fined by the local authority.

I will pass on an observation made recently in my backyard: My wife was cleaning a window of hardness spots from sprinkling the lawn. She used dilute vinegar. When finished she laid the vinegar soaked towel on the grass, removing it a few minutes later. The grass died where she had laid the towel. It is just coming back after about 2 weeks. My son backed this up saying he'd heard this suggested before as a home remedy herbicide.

BromicAcid - 5-8-2004 at 18:30

Searching though the newsgroup archives on google I came to a similar conclusion. 1 gallon of vinegar combined with 1 cup of salt supposedly kills any plant like a charm. However on the scale that we buy chemicals the price of vinegar is comparable with the price of synthetic killers.

Nevertheless it seems my employers have given up on trying to kill the lots any more. We got a concentrated herbicide from State Chemical in a large metal drum with instructions to dilute 1 gallon with 10 gallons of water. The drum was 20 gallons so therefore we expected to get 220 gallons out of it. However the representative of the company told us that it would make over 1300 gallons.

When I told my boss that it would only make 220 gallons she called State and they said that it would make 1300 gallons despite what the sticker said. We mixed a batch per the directions on the drum and it still did not kill the weeds. Considering my work spent $800 on that drum we have not heard anything more on spraying again after being ripped off so thoroughly.

Coincidently Unionised, there is a place down the street from my work that sells goats. Maybe we should pick up a few and tag them and just let them loose.

unionised - 7-8-2004 at 10:03

IIRC here in the, UK mis-labeling or mis-representing pesticides is a criminal offence. You might want to check on this and have "a quiet word" with the supplier.

chemoleo - 16-8-2004 at 16:05

Have a look at this:

http://story.news.yahoo.com/news?tmpl=story&cid=1802&...

They are debating the use of atrazine - a potent and profitable herbizide.
Now, atrazine is to be banned in the EU because scientists found that it was disrupting hormones in wildlife -- in some cases turning frogs into bizarre creatures bearing both male and female sex organ (quote).
Interestingly enough - it is not banned in the US of course - it's the second leading weed killer after all (would be bad for economy) - and the reason why it isn't banned is this :
" Hormone disruption, it read, cannot be considered a "legitimate regulatory endpoint at this time" -- that is, it is not an acceptable reason to restrict a chemical's use -- because the government had not settled on an officially accepted test for measuring such disruption."

Unbelievable, huh?
Frogs are mutating, and they dont bother to ban it. I wonder how many other side effects it has. Who knows, maybe this is why it makes so many people allergic against this or that...(just as a random example)

I guess you can see now why I am not a big fan of herbicides ...