Imphal city: Call for public awareness

Prof N Irabanta Singh *

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

Introduction

It is good news that Imphal city could secured a place in the second round of “Fast tract smart city” competition which have selected 13 more smart cities which was conducted by the ministry of Urban Development and Housing and Urban Poverty Alleviation, Government of India (The Sangai Express, May 26, 2016 issue). While planning about a smart city we need to give emphasis on bio-pollutants available in our environment. The Congress grass (Parthenium hysterophorous L.), a native of Central and Southern America is a major weed both urban and agricultural situations throughout India.

Status and seriousness of Parthenium problem

In Imphal city, the weed was reported first by the present author along Imphal-Dimapur road (NH39) at Mantripukhri Truck parking area during 1994. Now, the weed has infested almost all areas of the Imphal city (Sanjenthong area, Wangkhei, Kongba near Meitei Mayek High School, Manipur College road, Singjamei, Kakwa, Canchipur (Indo-Myanmar road); Singjamei-Kshetri leikai, Khongman, Kongba Area; Kongba-Khurai road; both banks of Nambul river such as Waheng leikai, Keishampat, Pisum; Uripok-Iroishemba road; Khwai bazar to Tera bazar (Imphal – Jiri road); Khwai bazar to Mantripukhri (Imphal-Dimapur road); Khwairamband bazar to Khurai road; Khwairamband bazar to Khuman Lampak road; Khuman Lampak road to Khurai; Pishum to Mayai Lambi road including northen side of the Polo ground near Auto boarding/deboarding area).

Our aerobiological investigations at 4 sites (Tiddim ground, Keishamthong Elangbam Leikai, Heirangoithong and Wahengbam Leikai) revealed that average number of Parthenium hysterophorous pollen of all the sampling sites were high at a distance of 1m rom the plants in horizontal (580 pollen/m3) and 1.5 m in vertical (530 pollen/m3) in July. Pollen grains of Parthenium were recorded throughout the year.

The highest monthly pollen concentration was found in June followed by July and September in horizontal profile. Whereas in the vertical profile the highest monthly pollen concentration was found in July followed by June and September respectively in the four sampling sites. During these months, in Tiddim ground and Keishamthong Elangbam Leikai were heavily infested with P. hysterophorous, the pollen concentration were high as compared to Heirangoithong and Wahengbam Leikai both in horizontal and vertical profiles.

Least number of P. hysterophorous pollen grain was collected in December (below 40%) at vertical as well as in horizontal profile in the four sampling sites. The correlation between the frequency of the average pollen number of horizontal and vertical of 4 different sampling sites using t-test was found to be 3.3 at 0.05% significant. The influence of meteorological factors such as temperature, wind speed, rainfall, and relative humidity on the variation patterns in the concentration of atmospheric pollen were studied.

It was observed that 250C-280C temperature, 4-5 km/hr wind speed, 60-70% RH, bright sunny and rain free days were favourable for high Parthenium hysterophorous L pollen catch. These weather conditions might be conducive for high discharge, dispersal and deposition of P.hysterophorous pollen. Too low or too high temperature, very high wind speed, high humidity and cloudy and rainy days hindered high pollen catch.

Such type of reports were also found from other cities of India. For instance, in Bangalore 40 – 60 % of the total aero-pollen sampled between 1981 and 1986 was from Parthenium suggesting the seriousness of the problem. In another study from Salt Lake City, East Kolkata, clinically 1 out of 6 patients showed ELISA positive reaction to Parthenium.

Partheniummenance on human and livestock health

Human health

Partheniumis known to contain sequiterpene lactone which induce severe allergic reaction in susceptible individuals who are continuously exposed. Itching, eruption developed on exposed parts of the body, particularly the upper eyelids side of the neck, parts of face, V of neck, from elbow and backs of knee.

Livestock health

Cows passing through patches of Parthenium suffer from inflamed udder, fever and rashes. In addition to itching, popular erythematous eruptions, loss of hair, marked depigmentation of the skin, developments of oedema ulceration and developments of lesions in the mouth and intensive and reduced milk yield when hungry cows eat the Parthenium weed in pastures because it contains harmful compounds.

Agents for Spreading Parthenium

The motor vehicles are one of the most important agents for spreading Parthenium seeds from one place to another. Prior to 1994, no parthenium plant was noticed in Imphal city by the present writer. The registration of motor vehicle in Manipur as on 31st March 1991 was 46688 (Truck-4017; buses – 1216; jeeps – 3596; cars – 2214; taxis – 273; two wheelers – 33146; three wheelers – 1292; tractors – 485; tailors – 317 and others – 159).

Whereas the registration of motor vehicles in Manipur as on 31st March 2015 was 249978 (Truck– 12709; buses – 1385; jeeps – 1542; cars – 22886; taxis – 4542; two wheelers – 191838; three wheelers – 14310 and others – 766). The amount increased in motor vehicles during last two decades is tremendous. The major portion of this vehicles (60% or more) are in the Imphal west and Imphal east district of Manipur. The frequent movement of the motor vehicle facilitate the spreads of Parthenium seeds in the roadsides of Imphal city resulted heavy infestation of parthenium plants.

Management strategies

There are three methods for control of Parthenium viz, mechanical, chemical and biological.

Mechanical control: It involves hand weeding including uprooting of young parthenium plants. It is an unpleasant job and made worst by the health hazards involved in handling Parthenium.

Chemical control: It is too expensive for farmers or general public to use.

Biological control: It can be perform either classical or bioherbicidal tactics because biological control is considered to be the cheapest and most effective method with minimum impacts.

a. Control of Congress grass (Parthenium hysterophorous L.) by using sickle pod (Cassia tora L.). The seeds of sickle pods if broadcasted on the Congress grass growing areas will suppress Parthenium through competitive displacement (please refer to The Sangai Express 18th Nov., 2015 issue).

b. The Congress grass (P. hysterophorous) can also be controlled using Mexican beetle (please refer to The Sangai Express 15th Oct., 2015 issue).

Discussion, public awareness and conclusion

The growth of Parthenium has been observed throughout the year but present with high abundance during June to August. This might be due to congenial climatic condition such as high rainfall, optimum temperature and high relative humidity which favoured the growth of the weed. It has started spreading like a wild fire in the Imphal city and its suburbs. The reason might be due to its prolific seed production and its lightness which could be easily blown through wind and carried away by the moving motor vehicles.

It has also its allelopathic effect on other plants. Till now, the weed has been found growing only along the roadside, wastelands and non-crop areas but if it is not controlled at the earliest, it might cause serious problems to the environment as Parthenium pollen causes contact dermatitis, rhinitis, asthma, etc., to susceptible human being and livestock.

Thus, the general public need to have awareness about the menace of the Congress grass. We have to realise our responsibility to wipe out this dreaded weed because the delay in addressing Parthenium issue in near future might end up in a great turmoil.