‘Sena’ a serious challenge to SL’s agriculture: Needs to be handled with great care and foresight


The introduction of the Fall Army Worm (FAW), known locally as ‘Sena’ to Sri Lanka, about four months ago is a disaster to all affected farmers, who need immediate effective relief, and it is our hope the government’s promises will be kept.

Commencing in the Anuradhapura and Ampara areas, it has spread to other parts, and it is estimated that 50% of the 80,000 hectares of maize in Sri Lanka is affected. It is claimed that FAW was discovered in the last century in the USA, and then spread to Latin America and much later to Africa and now Asia.

All attempts to eradicate it have failed and the strategy is to minimize its harm in a cost effective manner. The preferred host for Sena’s development is maize, from where it can spread to other plant hosts like rice and sugarcane, with serious damage to both animal and human food needs, and the rural economy.

The strategy being adopted in Sri Lanka too is one of reducing the pest load to levels that would make containment possible in a cost effective manner. But already the human predators (HP) have become operational. Moves are afoot to remove the existing ban on import of Genetically Modified (GM) seed varieties to enable a ‘Sena’ resistant variety of maize seed to be imported.

It cannot be propagated and has to be replaced each year with imported seed from the MNC Monsanto at high cost. Further, ‘Sena’ can overcome the resistance to it of the seed variety quickly. This course was dropped in Africa as it is costly and ineffective and is a danger to other plants, and must be opposed.

To reduce the ‘Sena’ density, many means have been tried, but with varying degrees of success. The human predators, who are after commissions, are promoting the chemical pesticide approach, but this kills the large number of natural predators as well thereby knocking out this invaluable biological but harmless weapon, which can also have an adverse impact on other cultivated plants.

It would appear that the Agriculture Department is using it as a short term weapon to reduce the ‘Sena’ load, but this should not be persisted with. It is costly and does more harm than good. Other measures like use of mechanical means, pheromones etc. are also being mentioned.

But when I spoke to scientific members of the LSSP Agriculture Committee, they were surprised that no mention has been made of the "push-pull" approach. Amongst the maize or other crops, plants like Desmodium (which is locally available) that repels the ‘Sena’ adult and larvae could be planted. At the same time other grasses that ‘Sena’ likes, such as Napier and Guinea, could be planted on the side to divert it away from the maize and other food crops. This should be done.

Thilak Kandegama, who is also associated with the LSSP, has had good results by following traditional practices like following the lunar calendar and avoiding planting when weeds and worms sprout during the Vesak and Poya periods. Besides planting at the right time, it is best if the whole area is done at once, and not staggered, as the later ones tend to get more affected.

He has also had success by four applications of ash when the maize is growing, wider spacing of plants, the use of organic farming (NEEM etc) The LSSP Scientific Agriculture Committee, while supporting these measures, lay much stress on the avoidance of mono-cropping over large extents. They stress the importance of mixed planting with different varieties of plants. Wider spacing to allow sunlight to fall on the plants is all important,

The government needs to have a systematic programme of integrated pest control on the above lines as a part of a national policy that stresses diversified small scale farming. The extension service should link the farmer to the researcher so that the two combine to study the changing local conditions and make suitable adaptations. This should be encouraged together with producer cooperative backing, rather than massive mono-crop farming, specially by Multinational Corporations (MNCs) that favour the development of pests and pauperize the village farmer.

The MNCs want to maximize profits in the shortest possible time without giving due consideration to the need for sustainable agriculture that will continue to provide a suitable environment for farming for the future generations. Agriculture must be cost effective for the small farmer to ensure that he has a viable livelihood.

They should not be forced into debt. With the granting of land ownership with the right to sell, the farmer will be forced to sell the land. In the absence of viable income sources in the rural sector, they will be forced to migrate to cities to become a cheap source of labour to urban MNCs, living meagerly in shanty towns, a prey to all the vice and negative culture that prevails there.

This is why the ‘Sena’ problem needs to be handled with great care and foresight. The invasion of our land by an insect predator must not be used to let in the foreign human predators, who can ultimately destroy rural agriculture, society and traditional culture.

I end with a quotation from "Can Humanity Conquer Nature" by Friedrich Engels: "Let us not, however, flatter ourselves overmuch on account of our human victories over nature. For each such victory, nature takes its revenge on us. Each victory, it is true in the first place, brings about the result we expected, but in the second and third place, it has quite different, unforeseen effects, which only too often cancel the first".

- Prof. Tissa Vitarana

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