|AGRICULTURE TRIBUNE||Monday, September 4, 2000, Chandigarh, India|
Congress grass the
scourge of India
Role of farm meteorology
Congress grass the scourge
DESIGNATED as one among the seven most devastating weeds of the world, parthenium hysterophorus L or congress grass nowadays happens to be a major biological pollutant of our environs. Despite expansion of literature on various aspects of this obnoxious weed, availability of reports on its control strategies and enough concern raised by the general public, the weed continues to spread its tentacles almost throughout the country. Since its inception into the Indian flora, this alien species has been captivating the attention of people in most of the states mainly because of its potential threat to the farm lands, native flora and fauna of a region and, above all, to the human beings. Once introduced, it occupies vast tracks of lands to the exclusion of the previously existing plants, gradually becoming the dominant plant of the area.
It happens to be great headache to the Indian scientist, naturalists as well as the physicians as it may attack the countrymen with a number of ailments like allergic skin diseases and incurable breathing troubles. Its present-day menacing proportions could be perceived as early as two-and-a-half decades back, when a Bombay weekly The Current sounded the alarm in an article with the warning Weed out congress grass or else face disaster saying further ....in another five years there will be no land left for crops, no fodder for cattle and a large population will be suffering from a deadly eczema........the situation is grim. It is a major calamity.
When this plant was sighted in Pune in 1956, dismissed as insignificant and of rare occurrence, nobody would have believed that this white-flowered weed shall become scourge of India within two decades of its inception into the floral wealth. Within five years of this report, the congress grass became a potent threat in Dharwar, Bombay-Karnataka region in erstwhile Mysore state. Only two years later, another report came when it travelled about 1700 km northwards, probably with the rooked cuttings of Jasmine and was recorded from Jammu in 1963. Subsequent reports on its spread and acclimatisation confirm that the weed sprouted at a furious pace naturalising in various regions of the country with varied agro-ecological conditions. From the plains of Punjab and Haryana to the desert of Rajasthan, from Manali, Nainital, Nilgiri and Tirupati Hills to sea level in Madras, from grasslands of Maharashtra to the Dandeli and Ammasandra forests in Karnataka and from thickly-populated metropolitan cities like Delhi to the isolated remote pockets of Andaman and Nicobar Islands, there is hardly any region left that seems to be hitherto unexplored by this troublemaker weed. The popularity of the weed is reflected from the variety of vernacular names it has acquired in the central and southern states of India such as broom brush, chatak chandni, gajar gavat, gajar buti or gajar ghas, gandhi buti, macherla kampa, osadi, pandhari phul, pittchi machipatri or white top.
Parthenium plant, with gregarious nature and white thick canopies of unattractive floral heads, belongs to the dicot family of flowering plants composite (Asteraceae) to which otherwise ornamentals like dahlia and chrysanthemum and oilseed crop plants like sunflower and safflower belong. These highly floriferous and profusely branched green herbaceous plants produce enormous mass of light-weight seeds, which, on being blown over and disseminated by the wind to far-off places, give rise to new plants. The outbreak of rainy season promotes germination of the seed beds lying in the soil to form dense mat of seedlings. The weed populations can easily be found growing along the roadsides, railway tracks, river banks, waste places, construction sites and peripheries of the agricultural fields and parks, both in cities and their outskirts. It is an aggressive and highly colonising species that seems to thrive under all kinds of habitats and its survival extends seasonal barriers.
Congress grass causes contact dermatitis and respiratory allergies in human beings, bender being hazardous to the life of plants and animals. In susceptible individual, the direct contact almost immediately produces itching and a persistent exposure may undermine bodys resistance. The contact dermatitis symptoms include redness of the skin, itching, water discharge from the patches and thickening of the skin. The skin becomes photosensitive making it hard for the patient to face the sunlight. Bare parts of the body, underjoints and soft tissues around eyes are more likely to be affected with contact dermatitis. Doctors at the PGI, Chandigarh, had once reported that 61 per cent of the patients of contact dermatitis from Chandigarh and its surrounding areas were found to be allergic to congress grass and suggested that in the absence of any permanent cure, the only remedy lies in removing the patient from the environment infested with this weed to hilly areas having its sparse plants. The suggestion, however, seems impracticable in most cases due to family, social or economic reasons. All the three systems of medicines allopathy, homoeopathy and ayurvedic seem to cure the patient only to a limited extent, that too giving only a temporary relief. A sesquiterpene laitone named parthenin has been held responsible for the cause of allergenicity of this weed. Contrarily, some research scientists working at the Cancer Research Institute, Bombay, however, feel that this otherwise toxic chemical, when properly processed, exhibits anti-cancer potential. Indian scientists have revealed time and again its possible usefulness in a variety of ways like use as an insecticide, medicinal value as a tonic for digestion, protein-rich substratum for raising edible mushroom, anti-malarial properties, etc, but on account of strong criticism, sometimes received from the researchers abroad, such findings remained at the experimental level and could not obtain approval for its exploitation at the commercial scale.
The uninterrupted growth
of parthenium has acquired national dimensions and needs
to be contained under nationwide programme on a war
footing. The parthenium menace in Australia was at one
time more severe, but the country launched an effective
national programme to control it. Cannot this be done in
India? The Government of Karnataka made the beginning in
its legal battle against the weed in 1975 by making it
legally mandatory for the people of the state to contain
the vigorous growth and spread of this weed under the
Karnataka Agricultural Pests and Diseases Act, 1968, in
terms of its Section 3, read with Sub-Section (7) of
Section 2. In case of non-compliance with the
notification, the person is deemed to have committed an
offence punishable with fine with the costs of preventive
or remedial measures, recoverable as arrears of land
revenue. On similar lines, issuance of a notification
making at obligatory for the residents for its clearance
from their private holdings and also the instructions to
the Public Works Departments, Agriculture, Forestry and
Health Departments for its removal from areas falling
within their jurisdiction may help to get rid of this
nasty weed. The lack of coordination among research
agencies and the administrative authorities along with
paucity of funds or exclusion of this troublemaker from
the governments list of priorities constitute
another factors contributing to the fast spread of this
weed. To bring its menace under control, a coordinated
effort of governmental and non-governmental agencies
along with persistent public support and NGOs
yeomen service spirit is required. The efforts in the
direction of education, public awareness and deweeding
must be given a planned though, otherwise the contents of
the current would become a reality and the congress grass
shall become the deadliest enemy of the country.
Role of farm meteorology
ECONOMIC progress and improvement of living beings depend largely upon the growth and efficiency of the agriculture sector, particularly in developing countries like India where the economy is predominantly based on agriculture. Agro-meteorology is an indispensable factor for the progress in this direction. Effective development and utilisation of a countrys land and water potential and their exploitation on a national basis are impossible without a basic knowledge of the influence of climatic conditions upon them.
The primary aim of agro-meteorology is to utilise and understand the interaction of knowledge of atmosphere and climatic processes with living organisms for maximising food production. It is concerned with the interaction between meteorological and hydrological factors on the one hand, and agriculture in the wider sense, including horticulture, animal husbandry and forestry, on the other. Its object is discover and define such effect and to apply knowledge of the atmosphere to practical agricultural use. Its field of interests extends from the soil layer where plant roots grow, through the air layer near the ground in which crops and trees grow and animal live, to the highest levels of interest to aerobiology. In additional to natural climate and its local variations, agro-meteorology is also concerned with artificial modification in environment (for example, by wind breaks and shelterbelts, irrigation, glass houses, etc.), in climate conditions of storage, either indoors for open field, in environmental conditions of animal shelters and farm buildings and during the transport of agricultural produce by land, sea or air.
The types of agro-meteorological problems include the protection against adverse production factors in the incidence and multiplication of pest and diseases of animals and crops, pollution of air, soil, crop and the animals, soil erosion, the environmental stress on crops and animals and the limits of constraints imposed on all farm operations; the incidence, frequency and extent of frost; the dangers of forest fires; losses during storage and transport, etc.
Improving agricultural techniques based on sound interpretation of meterological knowledge is the next step on the agro-meteorological problems. These would be designed to overcome the dangers listed above.
In the field of agro-meteorology, there have been extensive works on crop weather models, which are useful in evaluating the time and degree of effect of various weather elements on crop yield. In the development of agro-climatic zoning, classification needed in establishing appropriate crop calendar and cropping patterns, in the simulation of crop growth under given hypothetical or historical conditions in solving environmental problems in plant breeding work, varietal trials and fertiliser research programmes and for use in operational climate act assessment for agriculture.
Thus, the knowledge of the effects of weather on crop yields has several benefits in better production and through yield forecasting to make in advance given the early warning on crop failures is particularly valuable. Agro-meteorology can assist in the strategy of food production i.e. the decision-making processes, which involves the correct assessment of weather factors. Weather and climate must be interpreted correctly in relation to having organisms as choice of crop, selection of farm animal, method of soil cultivation, timing of farm operations helps in the correct choice of land use, production planning and genetic planning.
By tracking the
statistics of what can happen and what has happened, risk
analysis in relation to future proposal can be
significantly improved. Weather forecasting of the
conventional type can play a helpful role, provided that
such predictions are reliable, adequately available and
most of all that effects of future weather are understood
in correct perspective one has to realise that the for a
forecast to be of any use at all, there must be some
action that the recipient can undertake, either to take
advantage of favourable circumstances or to minimise the
Poultry and farm forestry
Place the nests inside the sheds, one to two weeks prior to the start of egg production.
Keep sufficient cold water available for the birds in the sheds.
The lights may be kept on during the cooler parts of the nights viz. late evening and early morning so that the birds can compensate the feed consumption of hot period of the day.
Any operation such as debeaking and vaccination may be done up to 14-16 weeks of age. The prices of eggs start rising from this month so there should be minimum of disturbance after the laying start.
Broiler chicks should be vaccinated against Ranikhet disease during first week of its age.
Use pond aeration, particularly during the early morning hours, the stocking density of fish is more than 4,000 per acre and the average weight of fish is more than 300 g.
Suspend the use of organic manures, inorganic fertiliser, supplementary feed if algal blooms develop in the pond surface.
Use an extra dose of lime @ 50 kg per acre (in liquid form) to avoid the risk of disease out break.