Winter wheat

Winter wheat(usuallyTriticum aestivum) are strains ofwheatthat are planted in theautumnto germinate and develop into young plants that remain in the vegetative phase during the winter and resume growth in early spring. Classification intospring wheatversus winter wheat is common and traditionally refers to the season during which the crop is grown. For winter wheat, the physiological stage of heading (when the ear first emerges) is delayed until the plant experiencesvernalization, a period of 30 to 60 days of cold winter temperatures (0 to 5 °C; 32 to 41 °F).
Winter wheat is usually planted from September to November (in theNorthern Hemisphere) and harvested in the summer or early autumn of the next year. In the Southern Hemisphere a winter-wheat crop fully 'completes' in a year's time before harvest. Winter wheat usually yields more than spring wheat.
So-called "facultative" wheat varieties need shorter periods ofvernalizationtime (15–30 days) and temperatures of 3 to 15 °C (37 to 59 °F). In many areas facultative varieties can be grown either as winter or as a spring, depending on time of sowing.
In countries that experience mild winters, such as in South Asia (India, Pakistan, Nepal, Bangladesh), North Africa, the Middle East and the lower latitudes (e.g.Sonorain Mexico), spring wheat (not requiring a period ofvernalization) is also sown in the autumn (November–December) and harvested in late spring (April–May) the next year. This spring wheat planted in the autumn and grown over the winter is sometimes also incorrectly called "winter wheat", and is also known as aRabi crop.
Hard winter wheats have a higherglutenprotein content than other wheats. They are used to make flour foryeastbreads, or are blended with soft spring wheats to make the all-purposeflourused in a wide variety of baked products. Pure soft wheat is used for specialty or cake flour.Durum, the hardest wheat, is primarily used for makingpasta. Almost all durum wheat grown in North America is spring-planted.
Winter wheat is grown throughoutEuropeandNorth America, and inSiberia.
Winter wheat is grown as acash cropor acover crop. Optimal growing conditions for winter wheat include high-drainage soil with medium texture. Mid-quality soil nutrient content is best for winter wheat, with an appropriate supply ofnitrogenbeing critical for the wheat to be able to establish itself in time before winter dormancy. In addition, a firmseedbedhelps protect the wheat over the winter period.In the United States, about 40% of the total wheat production is of a strain known as hard red winter wheat, with soft red winter wheat contributing another 15% of the annual wheat crop. There are also winter varieties of white wheat.Soft red winter wheat is also grown in the Canadian province ofOntario, along with white winter wheat.
Winter wheat was brought toKansasby German-Russian Mennonitesin the 19th century.Bernhard Warkentin andMark A. Carletonplayed a major part in the spread of winter wheat as a commercial crop. Warkentin organized mills in central Kansas and imported seed fromUkraineto meet growing demand. Carleton worked for theUnited States Department of Agriculture(USDA) as a crop explorer. He went toRussiato find other wheat varieties and worked withKansas State Universityresearchers to develop new ones. Winter wheat production quickly spread throughout theGreat Plains, and was, as it still is, usually grown using the techniques ofdryland farming.
Fortemperate climatezones such as Canada,increases in yields for winter wheat due toclimate changeare predicted. ForUkraine, where temperatures are increasing throughout the year and precipitation is predicted to increase, winter wheat yields could increase by 20–40% in the north and northwestern regions between 2010 and 2050.