ABSTRACT
Improving water management in winter wheat Q. Xue, J. Rudd, J. Bell, T. Marek and S. Liu, Texas A&M AgriLife Research and Extension Center at Amarillo, USA
1 Introduction
2 Winter wheat yield
3 Yield determination under water-limited conditions
4 The role of measuring evapotranspiration (ET)
5 Water-use efficiency
6 Wheat yield, evapotranspiration (ET) and water-use efficiency (WUE) relationships
7 Case studies
8 Future trends and conclusion
9 Where to look for further information
10 References
Wheat (Triticum aestivum L. em. Thell) is a major crop in the world and is the number one food grain consumed directly by humans. Wheat is grown in a wide range of environments around the world and has the broadest adaptation of all cereal crop species (Briggle and Curtis, 1987). Therefore, wheat production plays a critical role in the world economy and food security. For 2016/17, the world wheat production is projected to be about 720 million metric tons. The European Union dominates the production with 157 million tons, followed by China (130 million tons), India (88 million tons), Russia (64 million tons), the United States (56 million tons), Canada (28.5 million tons), Pakistan (25.3 million tons), Australia (25 million tons), Ukraine (24 million tons) and Turkey (17.5 million tons) (https:// www.statista.com/statistics/237912/global-top-wheat-producing-countries/). Wheat is also widely traded in the world market, with the United States, European Union, Australia, Canada and Russia being the major exporters (Fischer et al., 2014). For example, the United States share of world wheat exports has ranged from about 16% to nearly 40% in last three decades (Fig. 1). Although wheat exports have a declining trend in coming decade, the United States will remain one of the world’s leading suppliers of high-quality
wheat (USDA-Economic Research Service, 2015) (https://www.ers.usda.gov/data-products/ chart-gallery/detail.aspx?chartId=52238).
