IMI-Resistant Mustard Hybrids

Why in News?

In the 2026-27 rabi sowing season, Indian farmers are set to begin the wide-scale cultivation of imidazolinone-resistant (IMI-resistant) mustard hybrids.  

• IMI Resistant Mustard Hybrids – The mustard varities that are resistance to imidazolinone herbicide.
• It is designed to overcome a parasitic weed called Orobanche, a major hurdle in oilseed production.
• Orobanche – A destructive root parasite that attaches to the mustard plant and drains water and nutrients (It has more recently been called Phelipanche.) 
• Edible oil deficit – India imported 16 million tonnes of edible oils in 2024–25, at about Rs 1.6 lakh crore.
• Mustard – It is the most vital oilseed crop to meet the edible oil demand, especially in the arid environments of North India.
• However, its yields have been suppressed throughout the year by Orobanche.
• Development Process – Unlike genetically modified (GM) crops, these hybrids were developed in a process called mutation breeding — where scientists breed crops to preserve certain natural mutations.
  • Mutation breeding – It is the process of exposing plant seeds or tissue to physical agents (like radiation) or chemical mutagens to intentionally induce genetic variations
• Key Enzyme – The process is based on an enzyme called acetolactate synthase (ALS), which is essential for plant growth.
• Normal mustard plants are killed by IMI herbicides because the herbicides inhibit ALS.
• Working of the New Hybrid
  • In the IMI-resistant mustard hybrids, a single DNA change makes the plant’s ALS enzyme resistant to imidazolinone (IMI) herbicides, freeing farmers to spray IMI herbicides directly over the field.
  • The herbicide kills weeds like Orobanche but leaves the mustard crop unharmed.
  • It’s especially effective against Orobanche because the herbicide travels through soil and plant tissues, reaching the parasite where manual weeding cannot.
• Benefit – Farmers don’t increase the demand for labour during the short, critical weeding period, and the research community because it protects oilseeds.

To know about GM Mustard, click here

Reference

The Hindu | New herbicide-tolerant mustard hybrids need diverse farming plans