GLYPHOSATE
1. Context:
The Union Agriculture Ministry restricted the use of glyphosate, a widely used herbicide.
The Supreme court is about to take up a plea seeking a ban on all herbicide-tolerant crops, including transgenic hybrid mustard & cotton.
2. Glyphosate:
- Glyphosate is a herbicide used to kill weeds, which are undesirable plants that compete with crops for nutrients, water & sunlight.
- As weeds grow at the expense of crops, farmers remove them manually or spray herbicides.
- Glyphosate is a broad-spectrum herbicide that can control a wide range of weeds, whether broadleaf/grassy.
- It is non-selective, killing most plants in the field.
- When applied to their leaves, it inhibits the production of a protein '5-enolpyruvylshikimate-3-phosphate synthase (EPSPS)'.
- This enzyme which is produced by plants & microorganisms, synthesises aromatic amino acids that are necessary for their growth.
3. Usage in India:
- There are 9 glyphosate-based formulations containing different concentrations of the chemical registered for use under the Insecticides Act, of 1968.
- These are approved largely for weed control in tea gardens & non-crop areas like playgrounds, railway tracks etc.
- Farmers apply glyphosate on irrigation channels & bunds to clear weeds, making it easier for water to flow & to walk through them.
- The scope for glyphosate use is limited for the very reason that it is non-selective.
- Designed to kill all plants coming into contact with it, the chemical cannot ordinarily distinguish between crop & weed.
- It can be used in tea or rubber plantations but not in fields where the crops & weeds are at almost the same level.
4. Government Action:
- The Ministry of Agriculture & Farmers Welfare, issued a notification stating that 'the use of glyphosate involves health hazards & risk to human beings & animals.'
- It was not banned completely but its use is restricted.
- The spraying of glyphosate & its derivatives shall only be permitted through 'pest control operators.
- Glyphosate application has increased only with the advent of genetic modification(GM) or transgenic technology.
- A 'cp4-epsps' gene was isolated from a soil bacterium Agrobacterium tumefaciens & incorporated into crop plants like cotton, maize, and soybean.
- This alien gene codes for a protein that does not allow glyphosate to bind with the EPSPS enzyme.
- The said GM crop can 'tolerate' the spraying of the herbicide, which then kills only the weeds.
| Nearly 81.5 million hectares were planted worldwide with herbicide-tolerant(HT) GM crops. The global glyphosate market is annually worth $9.3 billion, with over 45% of use on account of GM crops. |
- Till now India's only GM crop officially under commercial cultivation is Bt Cotton.
- This has 2 alien genes-'cry1Ac & cry2Ab', from the soil bacterium Bacillus thuringiensis, that code for proteins toxic to the American bollworm, spotted bollworm, tobacco caterpillar insect pests.
- Neither the Centre nor the State government has succeeded in stopping the cultivation of illegal HT cotton.
- Having failed to curb the illegal sales of seed, the Centre is trying to nip the problem in the bud, by cutting the access of farmers to glyphosate & allowing its use only through pest control operators.
5. Health Concerns:
- The World Health Organisation's International Agency for Research on Cancer (IARC), classified glyphosate as "probably carcinogenic to humans".
- This was based on evidence for cancer in experimental animals from pure glyphosate, as opposed to that in humans from real-world exposures through diluted formulations.
- The US Environmental Protection Agency, held that there are no risks of concern to human health from current uses of glyphosate & no evidence of it causing cancer.
- The European Chemicals Agency has concluded that classifying glyphosate as a carcinogenic, mutagenic or reprotoxic substance is not justified.
- The Union Environment Ministry's Genetic Engineering Appraisal Committee(GEAC), recommended the commercial release of GM hybrid mustard.
- This crop can tolerate the spraying of glufosinate ammonium, a non-selective herbicide similar to glyphosate.
- GEAC is set to take a call on approving glyphosate-tolerant Bt cotton, whose illegal cultivation is an open secret.
6. Epilogue:
All eyes are on the Supreme Court, scheduled to hear a plea challenging the GEAC's nod for the transgenic hybrid mustard & seeking a ban on all HT crops.
