By Charles Mkoka, SciDev Net
LILONGWE-- Officials in Malawi are working flat out to promote
safe alternatives to the agricultural pesticide methyl bromide,
whose use they hope to phase out by the end of the year. If they
succeed, Malawi will be the first in southern Africa to phase
out all non-essential use of the chemical.
Methyl bromide is widely used to kill pests that damage tobacco,
a cash crop and principal source of foreign capital for Malawi.
But few farmers are aware that the pesticide is hazardous to human
health and the environment, and is partially responsible for depleting
the ozone layer of the Earth's atmosphere.
Parties to the Montreal Protocol on ozone-depleting substances
are required to stop using methyl bromide. The deadline for developing
countries is 2015. "We are currently ahead of schedule,"
says Aloysius Kamperewera, deputy director of environmental affairs,
the government department that is coordinating the work.
"Malawians need to consider the long term adverse effects
of the substance," says Raphael Kabwaza, director of environmental
affairs. "It might not be tomorrow, next week or next month,
but the effects of methyl bromide on the environment are disastrous.
"Malawi's Agricultural Research and Extension Trust (ARET)
has intensified efforts to raise awareness among farmers of the
threats posed by methyl bromide, and of its alternatives. The
campaign is targeting farmers with leaflets, articles in the press,
farm visits and training conducted by ARET staff. Customs officials
have also been notified that any imports of the chemical after
31 December should be impounded. Officials will be trained in
order to enforce the forthcoming ban.
One of the alternative approaches to pest control being promoted
is the use of 'soil-less culture', since a principal tobacco pest
— a microscopic 'nematode' worm — lives in soil. In
'soil-less culture', plants are grown in trays that float in plastic
ponds set above the ground. Each tray has 200 compartments containing
a single tobacco seed and a mulch made from pine bark to enhance
root development. The seeds absorb nutrients from the water —
which is supplemented with fertiliser — and use the bark
Two other alternatives being recommended are the pesticides 'metham
sodium' and 'dazomet' (traded in Malawi as 'Basamid'), both of
which are also toxic and should be handled with care, but are
considered safer than methyl bromide.
"There is need for more time for the rural farmers to understand
the phase-out of the substance," says Kamperewera describing
the challenges ahead. "It is a gradual process, but they
will embrace the idea with time.
"According to ARET officials, about 71,500 metric tones
of methyl bromide are used worldwide every year. Seventy five
per cent of this is used in developing countries. Malawi is the
second largest user of methyl bromide in Africa after Zimbabwe.
Each year more than 130 tonnes of the chemical are used, with
tobacco growers using 85 per cent of this.
Montreal Protocol's Multilateral Fund to Assist Developing Countries
is supporting Malawi's phase out of methyl bromide.