In India, the large-scale cultivation of new imidazolinone-resistant mustard hybrids is planned to begin during the 2026-27 rabi season, between October and April. These hybrids have been developed to overcome the parasitic weed Orobanche, which causes significant losses in oilseed production.
The country has long faced a significant shortage of edible oils. It is reported that India imported about 16 million tons of oil in the 2024-25 period, spending approximately 1.6 lakh crore rupees on these imports. Mustard is considered one of the most critical oilseed crops to meet this demand, especially in the arid regions of North India.
However, mustard yields have been under constant pressure due to Orobanche, a destructive root parasite that attaches to the soil and absorbs water and nutrients from the plant. This parasite is also referred to as Phelipanche in some publications.
How Does the New Method Work?
The new hybrids are not genetically modified organisms; they were developed using a method called mutation breeding. In this approach, researchers preserve and propagate naturally occurring mutations in the plant.
At the core of this technology is the enzyme acetolactate synthase (ALS), which is vital for plant growth. Normal mustard plants die because IMI herbicides inhibit this enzyme. In the new hybrids, a single change in the DNA makes the ALS enzyme resistant to the herbicide, allowing farmers to apply the chemical directly to the fields.
This way, the herbicide targets only the weeds. The method is particularly effective against Orobanche because it reaches areas that manual weeding cannot.
Benefits for Farmers, Caution from Experts
Farmers welcome these hybrids as they do not increase labor needs during periods when workforce availability is limited and weed control must be done within a short timeframe. Researchers also believe these products can help protect oilseed production.
On the other hand, some experts emphasize the need for caution in the long-term use of this technology. Geneticist Deepak Pental from Delhi University recently noted in an article published in Current Science that while the short-term benefits are clear, weeds may develop resistance over time.
Pental explained that if farmers rely on the same type of herbicide for many years, strong selection pressure will arise, leading to the emergence of resistant or less sensitive weed populations. This would weaken the herbicide's effectiveness and eventually cause the production system based on this chemical to fail.
Different Approaches Needed for a Lasting Solution
According to Pental, the new products should not be seen simply as a chemical substitute for manual labor. Instead, they should be part of a broader agricultural strategy that combines various weed control methods.
The expert recommends crop rotation, alternating herbicides with different modes of action, and continuing manual weeding to remove weeds that survive chemical treatment to ensure the system's durability over several years.
Pental's assessment: A single herbicide mode of action cannot form the foundation of a sustainable weed management strategy.
As India promotes IMI-resistant mustard this season, the real challenge will be integrating powerful agricultural tools not as standalone solutions but as components of a long-term, scientifically balanced program.
