India will introduce Imidazolinone (IMI)-resistant mustard hybrids during the 2026-27 rabi season to combat the parasitic weed Orobanche aegyptiaca (broomrape). This initiative aims to increase domestic oilseed production and reduce reliance on expensive edible oil imports, which cost India approximately ₹1.6 lakh crore in 2024-25.
The Orobanche Menace and Management
- Parasitic Nature: A holoparasitic weed lacking chlorophyll, Orobanche uses root structures called haustoria to siphon water and nutrients from mustard plants, causing yield losses of 20%–50%.
- Propagation: A single shoot produces ~5,000 microscopic seeds, which can remain viable in the soil for up to 20 years. Germination is triggered by strigolactones exuded by host roots.
- IMI-Resistance Mechanism: Developed via conventional mutation breeding (not GM), these hybrids feature a structural DNA mutation in the Acetolactate Synthase (ALS/AHAS) enzyme. This prevents Imidazolinone herbicides from binding to the crop, allowing targeted weed control without damaging the mustard.
- Integrated Weed Management (IWM): ICAR advises against over-reliance on chemicals to prevent “superweed” evolution. Recommended practices include crop rotation (wheat/chickpea), herbicide rotation, trap cropping, and manual extraction.
IASPOINT Booster Facts
- Regulatory Status: Unlike transgenic DMH-11, IMI-resistant varieties are non-GM and do not require GEAC clearance; they are governed by the PPV&FR Act, 2001.
- Market Context: India imports 55%–60% of its edible oil. Mustard (Brassica juncea) accounts for over 40% of indigenous oilseed production.
- Global Precedent: IMI-tolerant technology is globally known as the “Clearfield” ecosystem, used in canola and sunflower since the late 20th century.