Congress grass menace in North-East India

Dr N Irabanta Singh *

Parthenium hysterophorus at Salem, Tamil Nadu :: Pix - Wikipedia/Thamizhpparithi Maari

Introduction

Congress grass (Parthenium hysterophorus L.) has been rapidly spreading globally and continually affecting our health, livestock, flora and environment. The fast invasion of this weed is attributed to its wide adaptability to extreme soil and climatic conditions, ability to grow throughout the year, shorter life cycle, and easy disposal by wind, water and movement of vehicle and animals coupled with the absence of neutral enemies like insects and diseases.

In this article, the writer will focus on
(i) Parthenium and its spread in NE India,
(ii) Aerobiology and Parthenium menance,
(iii) Effect on the human and animal health,
(iv) Effect on biodiversity,
(v) How to kill Congress grass,
(vi) Recommendation and future strategies

Parthenium and its spread in NE India

Systematic field surveys were made on National Highways, State Highways and along the railway tracts of the North Eastern States during July to September, 2015; August to September 2016; April to August, 2017. The longitude and latitude of each Parthenium spotted place was recorded with the help of GPS.

Manipur – Parthenium was spotted highest in the State highways (Mayai Lambi) followed by NH-39, NH-150 andNH-53. In all the selected National Highways and State Highways of Manipur, heavy infestation ofParthenium weed was recorded except in NH-53. In the roadsides, one can easily observed dominance ofParthenium over other weeds.

Nagaland – Dimapur district is one of the thickly populated districts of Nagaland. Field survey conducted in Dimapur to Imphal National Highway and Dimapur to Patkai Autonomous College crossing and its adjacent areas revealed heavy infestation of Parthenium in front of Nagaland bamboo resorts centre and in front of Parth fuel service (5miles) along NH-29.

It was also detected at Podum-pukhuri Block –I (Lane no 1) in front of Hollatoli School, Podum-pukhuri Block-II (Lane no 2) vear sand and bricks querries (NH-29), on the bank of Podum pukhuri, Podum pukhuri village road near Florida nursery, Duroga Pather areas, Hill nursery, Ford City Service Centre, in front of Assam Rifles Trainning Centre School (NH-29), infront of Sandal wood nursery, in pring Valley School.

Road leading to Dimapur airport. Surprisingly, the roads leading to villages in the district were also found to be infested with Parthenium. The campus of The Global Open University, Nagaland, Sodzouhou village was also found infested with Parthenium.

Assam – Heavy infestation withParthenium was noticed in NH-31 (Gate of Narayanana Specialty Hospital Gauhati Gate; Barpeta road near Manikpur and Howly, NH- 31c (Bodoland), NH-37 (Mahatma Gandhi Memorial Hospital Campus).

Convent School Gate, Berama area, Nagaon Paper Mill Gate, Amlighat, Bogaonguri Loha, Jugulgaon, Kohargaon L.P. School, Homara, Bhomorachuri Kuch, Batamori, Timnel Village – all in NH-37. Heavy infestation withParthenium weed was found in these places. The weed was also spotted at one place in Silchar (South Assam) – Agartala (Tripura) road.

Arunachal Pradesh – Mild infestation with Parthenium was observed along the NH-52. It was spotted at Government middle Primary School compound, Naharlagun, Piwan opposite Forest office and Tourist Information Centre near Banderdewa. Heavy infestation with Parthenium was detected on either side of NH-52 at Banderdewa (Assam-Arunachal Pradesh Border) which might be one of the sources of spreadingParthenium in Arunachal Pradesh.

Sikkim – Parthenium infestation was noticed near Rangpur Government School campus, Mazhitar, Border Road Organization Office campus, Mazhitar and Rangpo Bazar. In Gangtok city, the presence of Parthenium was not noticed.

Tripura – Parthenium infestation was noticed in the International Fair ground, Hapania, in and around Tripura Medical College campus, Hapania; near GB Hospital (Tila), Akhuopura Road, Airport road, Radhanagar Bus stand (North), Jogendranagar (Bon Kumari Bazar) and Agartala – Assam Road (NH-44) near Badarghat Bund. Mizoram – Survey work not yet started.

Aerobiology and Parthenium menance

Earlier the presence of Parthenium pollen in the air having potential for allergies was reported from Central and Southern India (Singh, 2008). Subsequently, it was reported in Eastern India (Gupta and Chandra, 1991) as well as N.E. India (Irabanta Singh, 2012). By now, it may be presumed that the air quality is likely to deteriorate throughout the N.E. India due to proliferation of Congress grass (Parthenium hysterophorus) that warrants more scientific studies.

Effect of Congress grass on human and animal health

Exposure to P. hysterophorus pollen extract leads to bronchospasm in some patients of bronchial asthma.Parthenium weed is also known to cause many human health problems (Anonymous, 1976; Kologi et al, 1997). In the beginning, dermatitis was found in agricultural labourers but now increasing number of city dwellers are being affected as the weed spreads into urban areas (Tower and Subba Rao, 1992; Gautam and Gautam, 2011).

In animals, Parthenium may cause clinical signs such as salivation, diarrhea, anorexia, pruritus, alopecia and dermatitis, loss of hair and marked depigmentation of skin. A study on toxicity of the weed to cattle and buffalo has shown that 10 – 50% Parthenium in diet can kill animals within 30 days (Narasinha et al, 1977).

Tainting of milk in cows was reported (Tudor et al, 1982). Parthenoium affects the animal health, milk, meat quality (Evan, 1997). Besides, it is likely to cause health hazards to wild animals too due to regular exposure even in the National Park such as Kaziranga National Park (Assam).

There have been efforts to monitor the pollen concentration in different regions of India so as to tackleParthenium linked health problems. These are to be addressed by the
(a) Parthenium Aerobiologists
(b) weed specialists
(c) Patients/NGOs/and
(d) Dermatologists in an integrated manner.

Effect on biodiversity

Congress grass (P. hysterophorus L.) is also a major threat to biodiversity as this weed quickly colonizes land leaving very little space for other herbs and plants to grow due to allelopathic effects on certain plants.

Such situation was noticed by the writer while surveying NH-29 in Dimapur (Nagaland) where the weed completely changed the biodiversity of the area. Such situation was also noticed in the National Highways of Guwahati-Dimapur. Effect on biodiversity is observed in some areas of Imphal city where the weed completely replaced other flora.

How to kill Congress grass?

(i) By uprooting completely and destroying as and when noticed.
(ii) By spraying Glyphosate (1.0 – 1.5%) for total vegetation control or metribuzing (0.3 – 0.5%) if grasses are to be saved.
(iii) By releasing Mexican beetle (Zygogramma bicolorata) for sustainable control.
(iv) By broadcasting seeds of Cassia tora (Sickle pod) at the places where Parthenium seedlings are coming up and
(v) By utilizing Congress grass biomass for making compost and vermicompost.

Recommendation and future strategies

(i) Large scale demonstration with people's participation in different districts of NE India states.
(ii) Publication and distribution of leaflets in vernacular languages.
(iii) Involvement of media for regular broadcasting/publications of information on Partheniummanagement and their spread.
(iv) Regular monitoring and eradication of Parthenium in newly infested areas.
(v) Proper quarantine measures are to be taken to prevent the infestation of weed in new area.
(vi) Lectures/demonstration programme on Parthenium control are to be organized among school/college students.
(vii) Control of Parthenium is to be ensured through municipal corporation, Gram Panchayat development authority and railway/other transport organization.