Hi Murali,

I fear that the harm has been done.

Concenring glyphosphate: Glyphosate-based herbicides all work on the same biochemical principle -- they inhibit a specific enzyme that plants need in order to grow. The specific enzyme is called EPSP synthase. Without that enzyme, plants are unable to produce other proteins essential to growth, so they yellow and die over the course of several days or weeks. A majority of plants use this same enzyme, so almost all plants succumb to Roundup. Glyphosphate acts In the same way that many antibiotics gum up enzyme production to kill bacteria, glyphosate gums up enzymes in plants to kill them. Glyphosate kills plants like antibiotics kill bacteria.

The question of safety is a hard one to answer because there is a lot of polarized and conflicting information. Here are a few things we can probably say with some certainty. Given the amount of glyphosate sprayed on the planet every day, it is probably safe to say that glyphosate is not violently toxic to people or animals. People do not have the same enzymes in their cells that plants do, just like human cells and bacteria differ enough that antibiotics kill bacteria cells but not human cells

On the other hand, most people react badly to glyphosate (and other chemicals mixed with it) when ingested or applied to the skin, so you want to avoid any contact with the chemical. Roundup will kill almost any plant, including aquatic plants, so you want to be sure to avoid spray drift onto other plants or into water. Any pesticide should be applied carefully.

Paraquat is the trade name for N,N′-dimethyl-4,4′-bipyridinium dichloride, is the organic compound with the formula [(C5H4N)2]Cl2. It is classified as a viologen, a family of redox-active heterocycles or similar structure. This salt is one of the most widely used herbicides. It is quick-acting and non-selective, killing green plant tissue on contact. It is also toxic to human beings and animals. It is linked to development of Parkinson's disease.[2][3] The name is derived from the para positions of the quaternary nitrogens. A variety of related compounds are used in textiles.

Paraquat interferes with electron transfer, a process that is common to all life. It is an electron acceptor in redox and radical reactions.

As an herbicide, paraquat acts by inhibiting photosynthesis. In light-exposed plants, it accepts electrons from photosystem I (more specifically Fd, which is presented with electrons from PS I) and transfers them to molecular oxygen. In this manner, destructive reactive oxygen species are produced. In forming these reactive oxygen species, the oxidized form of paraquat is regenerated, and is again available to shunt electrons from photosystem I to start the cycle again. Paraquat is often used in science to catalyze the formation of reactive oxygen species (ROS), more specifically, the superoxide free radical. Paraquat will undergo redox cycling in vivo, being reduced by an electron donor such as NADPH, before being oxidized by an electron receptor such as dioxygen to produce superoxide, a major ROS. 2,4-D is a synthetic auxin, which is a class of plant hormones. It is absorbed through the leaves and is translocated to the meristems of the plant. Uncontrolled, unsustainable growth ensues, causing stem curl-over, leaf withering, and eventual plant death. 2,4-D is typically applied as an amine salt, but more potent ester versions exist as well.

Hence, Murali, I think that antidotes are useless fr these three potent herbicides, of which paraquat is very toxic for humans as well.

Cheers,,

Frank

Dear Frank.

Thank you very much for your informative answer. Its really gives  the fact that, these herbicide are unable to manage if farmers are unknowingly sprayed. Anyhow, we have to find suitable antidote for these herbicides to save the crops. Since, most of the farms, this is a herbicide problems are noticed frequently, as a scientist i am not able to answer for this situation. The farmers who cultivate good crop is suffering because of these herbicides due to some reasons.

My question is that, is it possible to discover a new antidote for these  herbicides. If its so, anybody attempted? Let me discuss further in the next mail

Cheers........

Murali Arthanari

Dear Murali,

I think that Dr Veroustraete has been very clear: there is no antidote for field use. These herbicides are systemic, so once they enter the plant they spread, inhibiting aminoacid synthesis, causing a ROS-shock and inhibiting photosynthesis or causing auxin toxicity.

I think trying to develop an antidote that is not harmful for the plants is a waste of time and the wrong way to deal with the problem. I also do not think it could be developed in a short time-frame, if at all. If farmers do not learn, an "antidote" would make the problem worse.

Regards,

Ruben

Dear Ruben,

Thank you very much for your suggestions and feed back about my questions.

With warm regards

Murali Arthanari

Dear Murali,

The antidotes for herbicides are the so called safeners. However, the known safeners like mefenpyr or isoxadifen are able to safen only a few mode of actions in single crops. And also then it depends on the individual chemical structure of the herbicide if the safener work well enough. The safener works also only together with the herbicide and not after the damage was already there. For glyphosate and paraquat as non-selective herbicides there is no safener known. It would be also very difficult to identify one because you need a kind of selectivity of the crop at the beginning. You cannot safen 100 % damage. 2,4-D is only able to control dicots and here we have the problem, that all known safeners work only on grasses. There is till now no dicot safener on the market.

Regards,

Andreas 

Dear Andreas,

Thank you very much for your interesting answer. What you have indicated in the text is absolutely correct. Anyhow, time will come to identify the suitable safener for the above non selective chemical.

Regards

Murali Arthanari

General herbicide-orientations from my side: 1. Although I have sprayed herbicides (incl. glyphosat in coffee/Tanzania) in many circumstances, I have become more and more sceptic and prefer --- whereever possible -- mechanical and other non-chemical-approaches. 2. Roundup = glyphosat is the worldwide most spread + used agrochemical and the findings from health and environmental Research accumulate recently in drastic propotions. I advise to be carefull. 3) We have many agro-chemicals the questionable, if not drastic environmental and biospherical Impacts of which have become known only years and decades after their introduction. 4) Good agronomical creativity and Cleverness can reduce, if not avoid herbicides to a very large extend.

With some limited moderate success I have sprayed a solution of lime and charcoal onto plants that have been sprayed with Glyphosate onto the desirable plants. This has to occur when the Glyphosate is still on the plant and wet. Like Frank Veroustraete said above, it works on a bio-chemical process, and I do not understand exactly why this has worked for me in the past. It is something that my father-in-law experimented with and saved about 40% of the Squash plants that were sprayed. I had similar results when meaning to spray with a insecticide and using the mixed glyphosate by mistake. I noticed the error early, called my father-in-law, and he recommended the treatment. Like my father-in-law, a percentage of my vegetable garden was saved. No proper scientific measurement here and I understand that scientifically, it is not a measurable experiment, however, if it works and can help people, why not share it. Also since this discussion is about the subject in the academic and scientific community, why not mention it to see if someone will study it.

Charcoal has huge adsorption properties that mostly depend on the producing process. This property can explain, at least partially, the positive effect mentioned by Roy Thompson.

There is a patent for Glyphoisate neutralisation in animals: WH67(R) Humic acids from Pharmawerk Weinboehla, Germany. If you need further information, please contact me.

احمد مجيد المشهداني

Mohammed Akram Alobaidy

You can use glyphosate at a concentration of 6.4 liters per hectare and for paraquat at a concentration of 2.8 liters per hectare.

2 4 D at a concentration of 250 ml per 100 liters of water