Floods Alter Punjab's Weed Map, PAU Warns of Emerging Agricultural Threats
Ludhiana, June 11, 2026:
The floods that swept across Punjab in recent years (2023 and 2025) have left behind more than damaged crops and battered infrastructure. Scientists at Punjab Agricultural University, Ludhiana, have now identified an emerging ecological concern: a changing weed landscape that could pose fresh challenges to the state's agriculture.
A survey conducted by PAU in flood-affected districts, including Hoshiarpur, Gurdaspur, Pathankot, Ropar, Amritsar and Patiala, has revealed the appearance of new weed species and significant shifts in weed flora. The findings point to the far-reaching impact of extreme weather events on agricultural ecosystems and highlight the need for vigilant monitoring and timely intervention.
Among the notable discoveries were three weed species not previously reported from these areas: wild radish or Jangli mooli (Raphanus raphanistrum), celery-leaved buttercup or Jal dhaniya (Ranunculus sceleratus), and marsh yellow-cress (Rorippa palustris). Scientists believe these species were introduced through floodwaters carrying seeds and vegetative propagules from upstream regions. In certain locations, marsh yellow-cress was observed infesting pea fields, signalling its ability to establish itself in cultivated areas.
The survey also documented noticeable changes in weed composition during the rabi season. Several species that were once uncommon have become increasingly visible in moist fields left in the wake of flooding. Such shifts are a cause for concern because weeds compete directly with crops for nutrients, moisture, sunlight and space. Many also serve as alternate hosts for insect pests and disease-causing organisms, increasing risks to farm productivity.
The Vice Chancellor of PAU, Dr Satbir Singh Gosal, revealed that the findings demonstrate how climate variability and extreme weather events can alter agroecosystems in unexpected ways. “Our understanding of the ecology, adaptability and invasive potential of these newly introduced weed species in Punjab remains limited. Continuous surveillance and timely management measures are essential before they become firmly established and threaten crop production, biodiversity and ecosystem stability,” he emphasized.
Highlighting the practical implications of the study, Dr Makhan Singh Bhullar, Director of Extension Education, PAU, urged farmers to stay alert during the ongoing kharif season. He advised them to report any unfamiliar plant species or unusual weed infestations to PAU experts, Krishi Vigyan Kendras (KVKs), Farmers’ Advisory Service Centres (FASCs), or the Department of Agriculture and Farmers Welfare so that appropriate action can be taken at an early stage.
Calling for a collective response, Dr Gosal stressed that safeguarding Punjab's agricultural biodiversity demands the active participation of farmers, scientists, extension personnel and other stakeholders. As climate extremes become more frequent, the battle against invasive weeds may begin long before they are visible across the landscape, making vigilance the first line of defence.