Wheat and Wheat Production Constraints

Abstract

Wheat is staple food for the major part of the world’s population. Approximately 630 million tons of wheat are produced annually, roughly half of it in developing countries (Peña 2007; Singh et al. 2011). It is especially important in India, in the USA, in Europe, and in the Latin and central-American countries including Argentina, Brazil, Bolivia, Chile, Mexico, Paraguay and Uruguay. Wheat production in the USA in 2011, was around 34.4 million tons harvested from 18.6 million hectares (Savary et al. 2012). Annual wheat production in the Latin American region, for example, used to be rather low compared to that in some technologically advanced countries and remained so, for some years (15 and 20 × 106 t). However, as in other countries, wheat productivity in this region has gradually increased during the past 20 years, reaching an average of over 2.0–3.5 t/ha, depending upon the country. This significant increase in wheat yield is mainly due to the introduction of high yielding cultivars and improvements in integrated disease management practices which are dealt with in the following chapters, followed by individual descriptions of some important wheat diseases that cause substantial yield losses in different wheat growing areas, of the world. Besides several diseases, the reoccurrence of scab, the emergence of an aggressive race of stem rust Ug99 and the spread of a relatively new disease—the Pyricularia blast, attacking cereals other than rice, are causing serious threats to wheat cultivation in much of the world (Vurro et al. 2012; Ralph et al. 2012).