It is India’s largest indigenous edible oil source farmed in nearly nine million hectares – mainly Rajasthan, Uttar Pradesh, Madhya Pradesh, Haryana and West Bengal.
But mustard is also a crop increasingly susceptible to infestation by Orobanche aegyptiaca. This is a parasitic weed that attaches to the roots of mustard plants and extracts nutrients, carbon and water from them. By depriving the host crop of these, it causes wilting, yellowing and stunted growth of the plants and, thereby, lower mustard seed yields.
“Till three years ago, there was no margoja (the local name for the root parasite) and my average yield was 9 quintals per acre. In good years with no disease, ola (hail) or pala (frost), it could be 12 quintals,” says Kokchand Sahu, a farmer from Gigorani village in Nathusari Chopta tehsil of Haryana’s Sirsa district.
The 42-year-old harvested a mere 6 quintals per-acre average of seed in the 2024-25 crop season (October-March). “I followed the Haryana Agricultural University’s recommendation to spray glyphosate herbicide – first at 25 grams/hectare after 30 days of sowing and then 50 grams after 55 days. It made no difference,” he notes.
Sahu has sown mustard on just six out of his total 32-acres holding in the current season, down from 14 in 2024-25 and 16 acres in 2023-24: “Farmers here traditionally grew mustard on almost three-fourths of their land. It requires only two irrigations, as against 5-6 for wheat. But margoja has dented our confidence. This time, I have planted wheat on 20, chana (chickpea) on four and jau (barley) on another two acres”.
According to Bhagirath Choudhary, director of the Jodhpur (Rajasthan)-based South Asia Biotechnology Centre (SABC), Orobanche has become the “No. 1 hidden threat” in the major mustard-growing areas of Haryana and Rajasthan.
The “hidden” threat is due to the weed’s underground location and its establishing connection with the host plant’s roots to steal nutrients and water. By the time the parasite’s shoots appear above the ground and become visible, the damage to the crop from diversion and undernourishment would have already occurred.
SABC conducted a field-based survey, including one-to-one interactions with 51 representative farmers, in Haryana’s Sirsa and Bhiwani districts to assess the severity and spread of the Orobanche infestation this season. The survey, undertaken between mid-December and first week of January, revealed heavy and uniform weed emergence in many fields. “The parasite density was markedly higher in repeatedly cultivated mustard fields,” informs Choudhary.
The reason is simple: A single Orobanche shoot produces 40-45 purple-coloured flowers, each further containing 4,000-5,000 very minute seeds. These remain viable in the soil for up to 20 years and disperse by wind and water to other fields. Once a strong seed bank is built, it creates conditions for rapid infestation. Farmers usually give the first irrigation for mustard 25-30 days after sowing. The soil moisture from that is, however, also conducive for the germination of the Orobanche seeds, followed immediately by their underground establishment and attachment to the mustard plant roots.
