The developing world's heavy dependence on staple foods such as rice, soya, wheat and maize makes for a precarious existence if these crops are ravaged by unexpected drought, disease, flood or freak weather - not uncommon events in poor countries.

Some say this is where the controversial research area known as biotechnology can help feed the starving millions, by engineering plant strains with improved resistance and yields.

"By bringing in this technology to make the same crop that people eat and grow, make it more insulated against some of the elements of nature, more nutritious...it will improve local production," said Channapatna Prakash, professor in plant molecular genetics at Tuskegee University, Alabama.

"If it does make a difference in their overall health and well-being with the least intervention, it needs to be looked at very carefully," he said. "If it does provide some solution in certain places and circumstances, then why not?"

Prakash is also a member of the U.S. Agriculture Department's agricultural biotechnology advisory committee.

Genetic modification (GM) involves exchanging or splicing genes of unrelated species that cannot naturally swap with each other and scientists say the applications are almost limitless.

The species can be vastly different, for example, inserting scorpion toxin or spider venom genes into maize and other food crops as a 'natural pesticide' to deter insects and birds from feeding on the plants, or fish antifreeze genes into tomatoes.

RESULTS HARD TO MEASURE, PROGRESS STILL SLOW

The tangible progress made so far is hard to assess as the various applications of biotechnology to Third World staple crops are still being developed. Scientists say the measurable results and possible benefits to farmers are still years away.

Test projects already underway include virus-resistant strains of sweet potato in Kenya, insect-resistant rice in China and papaya in southeast Asia, as well as various cassava and maize projects in other African nations.

Perhaps the most famous to date - and also controversial - is 'golden rice', which many see as having come to represent the hopes and fears about biotechnology, even though not one single seed of it has yet to be planted commercially.

Rice is the most important crop in the developing world and is eaten by close to four billion people every day. It accounts for around 80 percent of the total calories consumed by 2.7 billion Asians, or half of the world's population.

In 1999, Swiss and German scientists developed a variety of rice engineered to produce beta-carotene, a substance which the body can convert to Vitamin A. In this way, they hope to stave off malnutrition in poorer nations where rice is a staple food.

'Golden rice', named for its yellow hue, is produced by splicing two daffodil genes and a bacterium gene into japonica rice, which is a variety adapted for temperate climates.

However, experts say many more years are needed before the Vitamin A trait can be worked into the thousands of other varieties grown in countries such as India and Bangladesh.

With such an important crop, genetic scientists are also keen to develop rice strains with resistance to insects, which can eat away yields in tropical Asia by more than 30 percent.

Many crops grown in Third World countries are effectively organic as smallholder farmers lack the money to buy pesticides and other chemical treatments - thus bringing more significance to crops which can resist insects and the usual field diseases.

PROGRESS HAMPERED BY TECHNICAL PROBLEMS...