The Apunba Imagi Machasing (AIMS), Imphal on Saturday raised alarm on the wide scale growth of Congress grass (Parthenium hysterophorus) in the state. It appealed to the state Forest minister and authorities concerned to wipe out the plant from Manipur’s soil.
AIMS stated that the plain areas of Manipur have had abundant growth of congress grass. Several studies have shown that congress grass is one of the most troublesome and noxious weeds, reducing crop production in America, Asia, Africa and Australia, it stated.
The said grass is grown everywhere on the roadsides of Manipur, it stated, adding almost all grasses along Manipur’s main roads are occupied by this plant. The aggressive dominance of this weed endangers biodiversity in Manipur as it contains dangerous toxins, including parthenin, hysterin, hymenin, and ambrosin, it mentioned.
Skin diseases and respiratory malfunction can be caused by contact with the plant in humans and animals, AIMS stated. Prolonged exposure to the plant can cause skin inflammation, eczema, asthma, allergic rhinitis, allergic bronchitis, hay fever, black spots, burning, blisters around the eyes, diarrhoea, and breathlessness, it further stated.
Congress grass pollen can also cause asthma (allergic bronchitis), especially among children who play outdoors as well as adults. The spread of the problem all over the body can cause significant discomfort, it stated.
Various animals, including horses and cattle, also suffer from dermatitis when Congress grass is consumed, which causes mouth ulcers and excessive salivation, it stated.
This plant kills cattle when fed a significant amount (10-52 per cent). In addition, it causes anorexia, pruritus, alopecia, and diarrhoea in dogs. It can also cause acute illness in cattle when fed and weaken the immune system, AIMS mentioned.
It has been reported that Congress grass has strong allelopathic effects on several crops. It may inhibit germination and radical growth in various dicotyledonous and monocotyledonous plants. It also affects the activity of nitrogen-fixing and nitrifying bacteria.
Pollens produced by parthenium are enormous (on average 624 million/plant), and at least 600-800 of them are transported away and deposited on vegetative and floral parts of the plant, it stated. If these pollen are left uncontrolled throughout the growing season, yield declines may range from 40 to 97 per cent. Moreover, the plant serves as a host for many viruses that cause plant diseases. A total habitat change has been attributed to congress grass in native Australian grasslands, open woodlands, riverbanks, and floodplains, it added.
It is a drought-tolerant plant and grows faster during the rainy season. Congress grass, “which was introduced” in Manipur a couple of years ago, is not native to Manipur and might be brought here intentionally to degrade the environment of Manipur, AIMS stated.
Because, unlike other drought-tolerant plants that can flourish in any soil type, this drought-tolerant plant is only found on the roadside of Manipur, it stated.
“It is obvious that it was planted by dropping seeds from vehicles onto the roadside. It is, therefore, a form of biological warfare to devastate the soils of Manipur with poppy in the hills and congress grass in the plains,” AIMS further stated.
