Letter: Saved by trees

Sir: Roy Hattersley has unwittingly hit the nail on the head while coming to the wrong conclusion in his piece on GM crops (Notebook, 21 August). There is no campaign against testing. Protesters who pull up crops are demanding a five-year moratorium on commercial growing while proper tests are being done.

His second point is even more important, but he's got it wrong again. We certainly need "an antidote to drought, flood and famine", but you don't get that by growing a different kind of crop. You get it by retaining trees, not cutting them down, particularly on steep slopes. Flooding of the Ganges is caused by logging in the Himalayas. Floods on the Yangtse have similar origin in the mountains of China.

The two notorious famines in Ethiopia were caused by the cutting of forest on steep hillsides to clear land for agriculture. Forest was reduced from 40 percent to 3 percent in two generations, so that soil was washed away during the rains into the Blue Nile, then down into the White Nile in Sudan, ending up in Lake Nasser in Egypt. No amount of growing a more prolific crop would have prevented this.

Trees are now being replanted in Ethiopia. Agroforestry, which combines trees with crops and livestock may yet save the day. What we need to do is follow the laws of evolution rather than think up hi-tech ways of outwitting nature.

JILL DONISTHORPE

Winsley, Wiltshire