Why did the percentage share of agricultural sector in the exports of the country declined in the period 1950-1990?

The decline in the percentage share of the agricultural sector in the exports of a country from 1950-1990 could be due to several reasons:

1. Industrialization: During this period, many countries underwent significant industrialization. This means that industries such as manufacturing, technology, and services grew rapidly, often at the expense of the agricultural sector. As these industries grew, they likely made up a larger share of the country's exports, thereby reducing the percentage share of agriculture.

2. Urbanization: This period also saw a large-scale movement of people from rural areas (where agriculture is usually based) to cities. This could have resulted in a decrease in agricultural production and therefore a decrease in the share of agricultural exports.

3. Globalization: The 1950-1990 period was a time of increasing globalization, which could have led to increased competition in agricultural products from other countries. This could have made it more difficult for the country's agricultural sector to maintain its share of exports.

4. Changes in agricultural policy: If the country implemented policies that reduced support for the agricultural sector, this could have led to a decrease in agricultural production and exports.

5. Technological advancements: The period from 1950-1990 saw significant technological advancements. These advancements often led to increased productivity in sectors like manufacturing and services, which could have led to these sectors making up a larger share of exports at the expense of the agricultural sector.

Remember, these are general reasons and the specific reasons can vary from country to country. To get a more accurate answer, one would need to look at the specific circumstances and policies of the country in question.