In the developing countries

In the developing countries death by starvation is indeed a real threat to hundreds of millions. Now it can be said that realistic ways of solving this problem are beginning to appear. Scientific and technological progress is making itself felt more and more in agricultural production. It is not only by way of improving farm machines and implements, of more effective chemical fertilizers to the farmer, but also of progress in selection and genetics, that is called in the West "green revolution". The first problem which scientists want to solve is the problem of "straw-grain" balance. "Tall stands of grain" are good for literary descriptions. For the farmer it means that the biggest part of the plant food from the soil goes not into the grain but into the straw. Now it is known that too much fertilizer adds height to the plant, which is not what the grower primarily wants. Besides tall stands of grain are easier beaten down by wind and rain and this only makes harvesting more difficult.

Looking for the solution of the problem selectionists focussed attention on "dwarf" varieties which had been practically forgotten both in Europe and America. In 1946 a United States selectionist brought from Japan a few grains of a dwarf variety of wheat. The first plantings were not a success. The variety didn't want to grow in the USA climate and in the USA soil. But the scientists soon found the variety carrying three dwarf genes, three "orders" to the future shoots not to grow in height. Experiments on crossbreeding were begun in the United States and in the Mexican National Agricultural Research Institute (now the international centre for improving varieties of maize and wheat). As a result two new varieties appeared on US farm fields, one of them soon set a yield record of 14.1 tons per hectare. The varieties developed by Borlaug won him a Nobel Prize and solved the grain problem in Mexico. They proved to be three times more productive than the ordinary varieties, and adapted themselves very well to the conditions of tropical and subtropical areas where because of short daylight hours wheat does not grow well. Mexico stopped importing grain and since the mid-sixties has herself been exporting about a million tons annually.

Many other countries, primarily those of tropical Asia, took an interest in the new varieties. In the course of 3-4 years, the hybrid wheats became a leading grain crop in this area. In India the "Mexican" varieties, further improved by local selectionists, were planted over an area of 4,000,000 hectares in 1966-69.

Scientists now turned their attention to another cereal that has been the main food for centuries – rice. In 1962 an International Rice Research Institute was founded on the Philippines. The local climate, in which three harvests a year can be grown, made it possible to carry on selection work very quickly. By 1965 two dwarf varieties of rice grew on farm fields. Besides doubling and trebling the yields, they matured a month earlier than the usual varieties of rice. Later, still more rapidly maturing hybrid was grown which requires only 90 days from planting to harvesting instead of the 140-180 days for ordinary varieties.

Selectionists working with maize and millet also succeeded in increasing yields.The developing countries have worked at the problem with such energy that American and European farmers can envy. In the United States it took 15 years to get a hybrid maize evolved into large-scale cultivation. In the developing countries 17 million hectares were planted to high-yield varieties of wheat and rice by 1969-70. The scientists of new national states themselves have contributed very much to the further improvement of imported varieties. In India, for instance, wheats with hightened immunity to plant diseases and highest protein content were obtained in the period of five years on the country's farm fields. In Sri Lanka and Malaysia preference is given to improved local varieties of rice which require only little changes in the set up cultivation techniques. Important selection work is being carried out wilh dwarf rice in Nigeria, Guinea, Niger and Mali.

Here are some of the initial (first) results of the "green revolution". Wheat production in India more than doubled; in Pakistan it nearly doubled; the rice harvest in Sri Lanka increased by nearly 60 per cent; the maize harvest in Morocco more than doubled. Some developing countries already are close to being able to meet their own grain requirements.

Дата добавления: 2015-11-14