Azhar Jatoi
For decades, it has blended almost unnoticed into Pakistan’s rural and urban landscapes—growing along highways, spreading across grazing lands, invading farmlands, and even appearing in public parks. Yet beneath its ordinary appearance, Parthenium hysterophorus, commonly known as parthenium weed, “famine weed,” or jaggar booti, has emerged as one of the most destructive invasive plant species threatening the country’s agriculture, ecosystems, livestock, and public health.
Today, Pakistan stands at a critical turning point as a long-running scientific initiative to control the parthenium weed transitions from international support to full national ownership, marking a major milestone in the country’s environmental and agricultural resilience.
A Silent but Widespread Threat
The impact of parthenium weed in Pakistan is both widespread and deeply personal. Farmers in Punjab, Khyber Pakhtunkhwa, and Azad Jammu and Kashmir recount how the aggressive weed crowds out crops, reduces fodder availability, and renders grazing lands unusable. Livestock that feed on contaminated fodder often suffer health complications, while agricultural productivity declines steadily.
Medical professionals have also raised alarms. Exposure to parthenium pollen and plant residue has been linked to skin allergies, respiratory problems, asthma, and other chronic conditions, especially among farm workers and rural communities. Ecologists warn that parthenium suppresses native plant species, undermining biodiversity and weakening already fragile ecosystems.
What makes the weed particularly dangerous is its resilience. It thrives in poor soils, produces vast quantities of seeds, and adapts easily to different climatic conditions. As one agricultural policy expert noted, “Parthenium is not just an agricultural nuisance; it is a national challenge that affects food security, livelihoods, biodiversity, and public health simultaneously.”
Science-Led Response to Parthenium Weed in Pakistan
Recognising the scale of the threat, Centre for Agriculture and Bioscience International (CABI) began working in Pakistan more than a decade ago to develop a sustainable and environmentally safe response. Instead of relying solely on chemical herbicides or labour-intensive manual removal—both costly and often ineffective—CABI adopted a long-term, science-based approach.
This strategy combined biological control, rigorous research, institutional partnerships, and community engagement. The goal was not just to suppress parthenium temporarily, but to build a system that Pakistan could maintain independently.
Breakthrough in Biological Control
At the heart of this initiative lies a major breakthrough in biological control. After years of testing, researchers introduced Listronotus setosipennis, a tiny stem-boring weevil that feeds exclusively on parthenium. By damaging the plant’s internal tissues, the insect significantly reduces its growth, flowering, and seed production.
Extensive host-specificity testing confirmed that the weevil does not attack economically important crops, such as sunflower, easing concerns among farmers and policymakers.
“This was a turning point,” said CABI Deputy Director Abdul Rehman, who led the programme. “Once farmers understood that the weevil targets only parthenium, acceptance increased dramatically.”
At CABI’s Rawalpindi facility, a specialised rearing system was developed, producing more than 3,000 weevils per month. Thousands of adult insects have already been released at strategic sites across Punjab, Khyber Pakhtunkhwa, and Azad Jammu and Kashmir. Early field observations show noticeable weakening of parthenium populations where the weevil has established itself.
Research Highlights the Cost of Inaction
Biological control was supported by extensive local research to quantify the real cost of parthenium infestation. Studies conducted at CABI’s Rawalpindi office revealed that maize yields can drop by 14 to 46 percent, depending on weed density. When replicated across regions and crops, such losses pose a serious threat to national food security, particularly for smallholder farmers.
Further research warned that climate change could enable parthenium to spread into new areas, increasing pressure on agricultural systems already under stress. Adding to the optimism, scientists also identified a naturally occurring rust fungus, Puccinia abrupta var. partheniicola, which weakens parthenium and complements the impact of the weevil.
Community Awareness and Behaviour Change
CABI recognised early that science alone cannot defeat an invasive species without public cooperation. As a result, community engagement became a cornerstone of the programme. Over 10,000 farmers across 438 villages were trained to identify parthenium and manage it safely.
Village-level campaigns promoted collective action, while partnerships with government departments integrated parthenium awareness into agricultural extension services. Urban outreach also played a role, with more than 2,000 city residents engaged through activities in public parks and community spaces.
A nationally broadcast documentary reached an estimated 2.2 million viewers, while a dedicated “Weeding Week” campaign mobilised around 1,400 farmers to remove parthenium from their local environments. As Abdul Rehman observed, “When people understand the damage this weed causes, they stop ignoring it.”
Education, Museums, and Public Engagement
Educational partnerships expanded the programme’s reach even further. The Pakistan Museum of Natural History collaborated with CABI to create an exhibit on invasive species, with parthenium as a central example. Thousands of visitors, including students, learned how a single invasive plant can disrupt entire ecosystems—and how science and society can respond together.
Transition to National Ownership
A major milestone was reached this year as CABI formally handed over live cultures of Listronotus setosipennis to six national institutions. These include the Pakistan Agricultural Research Council, University of Agriculture Faisalabad, Nuclear Institute for Agriculture and Biology, Entomological Research Institute of AARI Punjab, Ghazi University Dera Ghazi Khan, and the Directorate of Agricultural Research in Khyber Pakhtunkhwa.
“This handover ensures Pakistan retains the expertise and resources needed to continue independently,” Abdul Rehman explained. “The system now belongs to national institutions.”
To support this transition, CABI organised a national training workshop in December 2025, training 22 officers and lab assistants in insect rearing, plant production, data recording, and field-release techniques. Importantly, the workshop strengthened collaboration among institutions that will now jointly sustain the programme.
A Model for Future Environmental Challenges
Pakistan now enters a new phase in parthenium weed management. With research capacity, biological control infrastructure, and public awareness in place, the focus shifts to integration and continuity. Provincial agriculture and environmental departments must embed biological control into routine operations, while communities continue monitoring to prevent reinfestation.
Beyond parthenium, the programme offers a replicable model for tackling other invasive species threatening Pakistan’s agriculture and biodiversity. By investing in science, institutions, and communities, the country has demonstrated how long-term environmental challenges can be addressed sustainably.
