Читать книгу Principles of Plant Genetics and Breeding - George Acquaah - Страница 22

In spite of a doubling of the world population in the last three decades, agricultural production rose at an adequate rate to meet world food needs. However, an additional 3 billion people will be added to the world population in the next three decades, requiring an expansion in world food supplies to meet the projected needs. The world population is estimated to reach 9 billion by 2050. Even though crop acreage in the US, for example, increased from 160 million acres (in 1926) to 225 acres (in 2015), arable land globally, including in the US, is on a steady decline due to a variety of factors, including the adverse impacts of climate change, surrendering of land to urban development, and salinization. Consequently, as the world population increases, there is a need for an agricultural production system that is apace with population growth but will be conducted on less land. Generally, it is estimated that about 40–60% of agricultural productivity is attributed to plant breeding efforts, through development of improved varieties. This calls for improved and high‐yielding cultivars to be developed by plant breeders. With the aid of plant breeding, the yields of major crops have dramatically changed over the years. Another major concern is the fact that most of the population growth will occur in developing countries where food needs are currently most serious, and where resources for feeding the people are already most severely strained, because of natural or human‐made disasters, or ineffective political systems.