Context
Recently the Indian Agricultural Research Institute (IARI) has developed rice varieties that enable farmers to spray Imazethapyr (herbicide) for controlling weeds in rice.
About
- IARI has developed two basmati varieties (Pusa Basmati 1979 and Pusa Basmati 1985) and two non-basmati rice hybrids (Sava 134 and Sava 127).
- These contain a mutated acetolactate synthase (ALS) gene that enables farmers to spray Imazethapyr for controlling weeds in rice.
- This gene is already found in rice and wheat – not introduced from soil microorganisms or different unrelated species, like inside the case of Bt cotton.
- The weed varieties are Echinochloa colona (normally known as jangli chawal), Cyperus rotundus (motha) and Trianthema portulacastrum (patthar-chatta).
Traditional approach of rice cultivation
- Normal rice cultivation includes getting ready nurseries, wherein the rice seeds are raised into young plant life which might be uprooted and replanted round 30 days later in the main field.
- After transplanting, the sector must be irrigated every 1-2 days to keep a water intensity of 4-5 cm.
- Water acts like a natural herbicide, preventing the weed seeds from germinating and killing the already emerged seedlings. However the technique consumes quite a lot of water.
Herbicide-tolerant solutions
- DSR and ZT wheat basically replace water and repeated discipline plows with a chemical herbicide (Imazethapyr) to take care of weeds.
- DSR dispenses with the need for any paddy nursery, puddling, transplanting and flooding of fields. The paddy seeds may be sown without delay, just like wheat.
- There is more or less 30% saving of water, aside from exertions in transplanting and weed management, and gas used for puddling.
- ‘FreeHit’ ZT technology makes it feasible to sow wheat without delay without any rice stubble burning or maybe land preparation.
- Alternatively, they can use a Happy Seeder without a rotavator that simplest cuts and leaves the crop residue on the sector.
How does the mutated ALS gene work?
- The ALS gene codes for an enzyme (protein) that facilitates synthesizing vital amino acids for plant growth and development.
- Imazethapyr sprayed on regular rice and wheat binds itself to the ALS enzymes, inhibiting their production of the amino acids.
- The herbicide will, then, kill the crop in conjunction with the weeds, because it can’t distinguish between the two.
- However the brand new technology consists of a mutated ALS gene, whose DNA collection has been altered using a chemical mutant or radiation.
- As a result, the ALS enzymes do not have binding web sites for Imazethapyr and the amino acid synthesis isn’t inhibited.
- The plants can now “tolerate” the herbicide, which only kills the weeds.
Concluding Remark
- The adoption of Direct Seeded Rice (DSR) and Zero Tillage (ZT) farming practices, which offer benefits including reduced water and fuel intake and take away the environmental pollution related to crop residue burning, is only to improve with the mixing of herbicide-tolerant technology.
- As those technologies are not genetically modified (GM), it ought to similarly facilitate their popularity and adoption amongst farmers and stakeholders.
Source: The Indian Express
UPSC Prelims Practice Question
Q. In India, the use of carbofuran, methyl parathion, phorate and triazophos is viewed with apprehension. These chemicals are used as (2019)
(a) pesticides in agriculture
(b) preservatives in processed foods
(c) fruit-ripening agents
(d) moisturizing agents in cosmetics
Ans: (a)