Malaysia: Continuous spraying of herbicide keeps dangerous introduced weed manageable

TASHNY SUKUMARAN The Star 16 Mar 16;

KUALA LUMPUR: A dangerous weed that was sweeping the nation last year is now contained and controlled.

“We have to continuously control the weed by spraying certain areas before the plant blooms,” said the Agriculture Department’s Plant Biosecurity Division head Faridah Aini Muhammad.

Parthenium hysterophorus, or congress grass, dubbed the “worst weed of the century” due to its ability to destroy native flora and crops and cause scarring rashes, was first discovered on our shores in Selangor in 2013.

It was later spotted in nine other states, forcing the authorities to take immediate action.

“People still report in if they see it, and we take action. However, it is under control – it has not spread over more land,” she added.

She said there were also more stringent conditions placed on the import of livestock and agricultural machinery, as it is suspected that the weed entered the country through this channel.

Currently, Kedah is home to the biggest infestation with 23.77ha, followed by Perak with 18ha.

Sabah is the least affected with just 0.09ha.

The other affected states are Perlis (2.68ha), Penang (2.8ha), Negri Sembilan (11.7ha), Malacca (4.05ha), Johor (3.6ha) and Pahang (1.19ha), bringing it to a national total of just 70.4ha or about 50 football pitches.

“It is still found mostly tepi jalan (by the roadside). But because of continuous spraying of herbicide we can keep it manageable, even with its large seed bank.”

Besides using herbicides to hold the weed at bay, the general public can use salt water in a 1:4 ratio of salt to water to destroy the weed.

Similar in appearance to ulam raja, Parthenium hysterophorus is classified as a dangerous pest under the Plant Quarantine Regulations 1981 and can quickly propagate.

It produces hundreds of thousands of seeds during its four-week life cycle, and the seeds can lie dormant for up to 10 years.

Anyone caught spreading or transporting the eczema-causing weed into or across Malaysia risks a RM10,000 fine or two years’ jail or both.

The Star first revealed that this weed was sweeping the nation in December 2014, with people in parts of Kedah reportedly suffering from itchy red rashes.

The highly allergenic plant can cause severe skin disease and hay fever.

It is also toxic to livestock such as goats and cows, causing fevers, ulcers, anorexia and intestinal damage.