• 10 Nov - 16 Nov, 2018
  • Rabia Mushtaq
  • Feature

Parthenium – a toxic weed – is capable of destroying native and most cultivable crops in our part of the world. MAG finds out how this weed is affecting the crops and ultimately, our ecosystem. Read on…

What is Parthenium?

Known as parthenium hysterophorus – Gajar Booti in Urdu – parthenium is an invasive, vigorous species of weed that tends to disturb the ecology and causes health issues among humans and animals, through direct contact. Its presence is enough to reduce crop production as it enters fields unknown to its damaging effects and also threatens biodiversity. The weed is usually spotted in bare, disturbed areas on roadsides and greatly stocked areas around watering points. Its erect stem and deep tap root turns woody with age. But as it grows, the dangerous plant develops several branches on its upper half and can grow up till two metres. Parthenium’s small, cream-coloured flowers sit on the tips of its many stems with each flower comprising of four to five black-coloured, wedge-shaped seeds, which are two millimetres long with thin, white scales. The leaves of the plant are pale green in colour, lobed deeply and are covered with soft, fine trichomes.

Origins of the killer weed

Parthenium is native to the region surrounding the Gulf of Mexico, Southern North America, Central America, Central South America and West Indies. The weed has successfully invaded more than 20 countries around the world, together with numerous islands and five continents. African countries are at a high risk of invasion and the weed is spreading at an alarming rate in many other regions including South Asia.

How it made its way into Pakistan?

The weed made its way to India before 1910 – via contaminated wheat grains – but was not recorded up until 1956. Ever since then, parthenium is said to have been spread like wildfire in India and Pakistan through different sources.

The weed travelled to Pakistan during the late 1980s via Chenab due to regular water flow and floods, and then it gradually spread in the country’s arid region. Its presence is proven in Punjab and Khyber Pakhtunkhwa through scientific literature and evidence. However, its existence in Sindh and Balochistan is based on observations by locals and organisations working to curb the green menace.

Dangers of parthenium in Pakistan

It is an invasive weed and not a part of Pakistan’s local flora or fauna. It looks like a pretty plant and resembles the jasmine flower. According to research, parthenium has adverse effects on humans, animals, crops and also the environment. If people touch it with bare hands or stay around the plant for a while, it may cause allergy, asthma, eczema and eye irritation. The consequences may take time to surface, also depending on individual’s capacity. And if the cattle consume it as fodder, they may suffer from blisters which may eventually turn its milk yellow leaving it to stink and the meat no more healthy for consumption. However, the constant use of the weed as a fodder may prove fatal for the cattle.

Parthenium is spotted near irrigated fields in Punjab, starting from Potohar, district Sargodha and Gujranwala, where most of its thrust can be seen on the edges of the fields. However, the plant can easily be rooted out, if or when spotted. For instance, if a farmer’s land is spread over one acre, they can easily pull out parthenium from their fields. But if they don’t, the plant is capable of spreading at an alarming speed. With the passage of time, the plant’s roots are able to release allelopathic chemical which halts the germination of crops and it easily overruns them. This usually happens because when the parthenium plant matures, it produces approximately 10,000-15,000 seeds, which possesses the potential to multiply at an increasing number.

Curbing the menace of parthenium

In order to find out how to curb this deadly weed, MAG got in touch with two representatives of Centre for Agriculture and Biosciences International (CABI) – an international not-for-profit, inter-governmental organisation, who has a rather different take on the invasive plant.

Dr Umair Safdar, Development Communication Executive for CABI Pakistan, talks about how the organisation is working to control parthenium in their preferred way. 

“Our organisation works on the biological control – natural ways to curb the growth of parthenium,” informs Dr Safdar, adding, “In Africa, CABI has worked on a biological control agent called Listronotus which makes a hole in the plant’s stem and helps destroy it before the flowering stage.”

According to experts at CABI, the use of weedicides can impact our agriculture adversely and less harmful weedicides barely work on these bad boys. “The seeds of parthenium can survive for 20 years. If they fall on a piece of land and find suitable conditions to flourish, then they are capable of germinating even after several years. A regular spray does not work on it; only glyphosate – herbicide applied to the leaves of plants to kill both broad leaf plants and grasses – deters it and the world discourages farmers to use the agent, as it is extremely harmful for other crops, especially food crops, which will eventually raise the issue of food security in the region,” Dr Safdar warns.

Ashfaque Ahmed, Training, Monitoring and Evaluation, Quality Assurance Manager at CABI reveals the presence of toxic plant in many parts of Sindh.

“We’re working in different districts of Sindh and have observed the presence of parthenium near mango orchids in Hyderabad, Tando Allahyar and Mir Pur Khas to name a few. So, this entire strip has been the breeding ground of parthenium,” he asserts. “We have conducted surveys in order to implement our next course of action,” says Ahmed.

“The weed has immense potential to damage the crops that eventually affects economy and the ecosystem. Using weedicides is not a good idea because it will impact the region’s food security,” he shares.

However, gardening enthusiast, Muhammad Izhar Ul Haq, does not seem to agree with the notion that parthenium poses as much danger as being reported. 

“The plant is invasive but there are studies that also talk about its benefits. The weed can be used to fertilise the land as it absorbs salinity. If cultivated on a barren piece of land, it has magnificent effects as it can make soil fertile,” Mr Haq shares the advantage of the weed.

The plant also has medicinal qualities. There are established studies that the weed possesses anti-inflammatory contents. “However, one cannot deny the many toxic qualities it possesses. For example, if the plant gets mixed with animal fodder, then it definitely poses danger to the cattle, but it does have benefits too,” concludes Mr Haq.

Dr Safdar of CABI is absolutely against the idea of the plant being used for consumption. “There are rumours being spread by local hakims that parthenium can cure diabetic and stomach issues, but that is not true and does not have any scientific evidence. There is extreme lack of knowledge regarding this and we’re working spread awareness in this regard,” says Dr Safdar reiterating the vision of CABI.

How to get rid of parthenium?

It is important to strengthen the technical aspect of controlling parthenium, but in order to stop the plant from growing, it is more important to create awareness among the public. A short-term way to control the plant is by pulling it from the roots and CABI is working to seize it using long-term biological control strategies. “But for that we need to import biological control agents. To start with this strategy, an NOC is submitted to the government, so as soon as we receive that – most probably next year – we’ll start working on it and try to control the growth of parthenium in approximately three years,” concludes Dr Safdar.