Preface

The need for more food is rapidly increasing as the world population is growing at a fast pace. The scientific community involved in crop production and its improvement is being called upon to find solutions to the expanding global demand for crop plants and their products. Two options are available to increase yields: the first consists of an increase in the areas under production, and the second, an improvement of productivity on existing farmland. Of the two options the second seems preferable, as it avoids the disruption of existing ecosystems as well as an increase in greenhouse gas emissions. In both cases two strategies can be adopted, one classical, of extensive industrial agriculture largely adopted in developed countries to produce major crops like corn, rice, wheat and soybean and another one, known as sustainable agriculture, characterized by a production more respectful of the ecosystem. The two strategies are not mutually exclusive and which one of the two should be adopted depends on the characteristics of local production methods and on economic and political considerations, as well as the choice of global versus local food production and consumption. In this context, to really improve the situation, we should focus our efforts on the areas of the world where the nutrition of the population should be improved, like Africa, India, Bangladesh, Pakistan, China and some regions of South America. In these areas the solutions to solve the problem of hunger should be local and specific, related to the real needs of the population and respectful of local traditions. The knowledge, experience and know-how available to the western world could be invaluable tools for improving their agricultural production. Application of our model of industrial agriculture should be avoided. Only by trying to understand what are the needs of these populations and exporting our knowledge to improve their situation can we hope to contribute to solve their problems. These considerations are developed in the first two chapters of the book. The following chapter will deal with genetic variability as an essential source of plant improvement. The following chapters will analyse basic physiological processes which represent bottlenecks for productivity and the efforts that could be directed to increase the efficiency of these processes. The topics analysed will be the genetic control of seed size; germination and seedling elongation, representing crucial steps in plant development; photomorphogenesis and the effects of light on aspects related to yield, such as photoperiod and shade avoidance, photosynthesis and the sink-source flux; and mineral nutrition. These topics will be covered in chapters 5 to 9. We will concentrate on factors that are directly related to yield, omitting those indirectly affecting productivity like herbicide- and pest-resistance, drought tolerance and cold resistance. In the last part of the book, attention will be given to some of the tools available to the researcher to achieve plant improvement. We will focus attention on available tools such as molecularly assisted breeding, gene editing, domestication of new species, heterosis and apomixis.