Biocontrol agents approved to tackle weed

The Department of Plant Protection has granted permission to the Centre for Agriculture and Bioscience International (CABI) to import two additional biocontrol agents from Australia.

This initiative is aimed at combating the invasive parthenium weed in an environmentally sustainable manner, minimising reliance on hazardous chemicals for its management.

CABI, a UK-based non-profit intergovernmental organisation dedicated to scientific research, has been at the forefront of controlling parthenium naturally in Pakistan since 2017.

The organisation has run mass community awareness campaigns under its Action on Invasives programme and has trained farmers in coping with the impact of parthenium and effective management techniques in collaboration with government agencies and public universities.

Last year, CABI introduced and released its first biocontrol agents, a type of weevil imported from South Africa, across various regions of the country following years of rigorous testing in quarantined laboratories.

Experts assert that biocontrol is an effective method for managing invasive non-native species. Unlike harmful chemical pesticides, biocontrol agents target specific pests or weeds, feeding and developing exclusively on them.

Parthenium, also known as famine weed, is recognised globally as a serious weed due to its detrimental effects on crop yields and human and livestock health. It has been dubbed the "suicide weed" in India.

Native to tropical America, parthenium has spread to multiple regions worldwide, covering 48 countries across Africa, Asia, and the South Pacific.

Experts note that parthenium entered Pakistan from India in the 1980s and has rapidly proliferated across the country's rural and urban landscapes. This invasive weed damages local habitats and adversely affects agriculture, particularly vital food crops like wheat, rice, and maize.

It now covers thousands of hectares, especially in the rain-fed districts of northern Punjab, Khyber-Pakhtunkhwa, and Azad Jammu and Kashmir, and has become dominant in wastelands, degraded areas, and along roadsides and water channels. Its presence has also been seen in parts of Balochistan and Sindh.

Abdul Rehman, Deputy Director of Projects Implementation and Research at CABI, emphasised the importance of adopting a multi-biocontrol agent approach in Pakistan.

"CABI, with its expertise in biological control, is focusing on importing two new biocontrol agents to manage parthenium weed, also known as Gajar Booti in Pakistan," he said.

He highlighted that many of the 48 countries affected by parthenium are deploying biocontrol agents to mitigate the weed's growth, which can reduce crop output by 46-90% and cause severe allergies and diseases in humans and animals.

Australia has screened and approved the release of 11 biocontrol agents for parthenium management. Other countries, such as India, South Africa, Ethiopia, and Sri Lanka, are also utilising an integrated pest management approach to control this noxious weed, emphasising community participation and biological methods.

Despite the promising potential of biological control, several challenges hinder the introduction of these agents in Pakistan.

Rehman pointed out that environmental factors, along with the complex and time-consuming approval processes, delay the import and release of biocontrol agents.

The first biocontrol agent required almost four years of quarantine testing before receiving government approval. Initially, it was restricted to wild rangelands and controlled areas, not agricultural fields.

Inadequate funding and technical expertise hinder biological control programmes. Rehman noted that reforming the regulatory regime could save time and resources, stating, "If an agent is rigorously tested in Australia or South Africa, we should not need to repeat the process here."

He expressed concern that, despite receiving permission to import two new agents, their release in Pakistan could take another four to five years and urged authorities to expedite the deployment process to one-year post-import.