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ARS Home » Midwest Area » Wooster, Ohio » Corn, Soybean and Wheat Quality Research » Research » Publications at this Location » Publication #261927

Title: Management of Pre-harvest Sprout Damage in Wheat and Improvement of Soft Wheat Quality in US

item Kweon, Meera

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/15/2010
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The United State Department of Agriculture (USDA) estimated world wheat production at 641MMT and US wheat production at 60.5 MMT in 2010/11. About 82% of the world wheat demand is for food and seed use, and about 18% for feed and residual use. Although pre-harvest sprouting occurs for all cereals, most of the damage occurs in wheat because wheat is the most widely grown cereal in the world. Pre-harvest sprouting in wheat occurs in 3-4 years out of 10 in major wheat-producing areas throughout the world including the Unites States. The areas in the US commonly affected by sprout damage are portions of the Pacific Northwest, the upper Midwest and the Northeast. Before wheat is harvested, kernels can start to germinate in the field when wet condition persists due to prolonged and repeated rain, and sprout damage may continue to occur during storage and shipment, resulting in significant economic losses through lower yield, decreased test weight, and activated enzyme complex in the seed. Pre-harvest sprout damage in US wheat ranges from very minor to very severe, and damage occurs mostly in narrow defined areas. The incidence and severity of pre-harvest sprout damage is quite unpredictable because of the variability of inopportune rains and undocumented differences in the susceptibility of prevalent varieties to pre-harvest sprouting. Naturally, not all varieties of wheat have an equal amount of pre-harvest sprouting tolerance. When wet weather continues for a prolonged period, even the most pre-harvest sprouting tolerant wheat varieties will eventually sprout. For example, the weather in Kansas State is usually hot with dry conditions following ripening of hard red wheat, which does not normally favor sprouting. But unexpected damage occurred in parts of the state during 1979, 1989, 1993, 1999, and 2004 when weather conditions were particularly favorable. Since the early 1970s, there have been numerous efforts in the world to improve the resistance to pre-harvest sprouting through wheat breeding programs and research on the genetics and physiology of seed development, dormancy and germination. However, the pre-harvest sprouting problem remains unsolved because of its sporadic occurrence and complex biology. Only a few wheat cultivars resistant to pre-harvest sprouting such as Clark’s Cream, Rio Blanco, Cayuga, and Jensen have been released, and Jensen is among the few resistant varieties still in commercial use. Most wheat cultivars planted currently in the US are susceptible to pre-harvest sprouting. As the severity of sprouting increases, acceptable food uses for wheat are limited. When sprouting in wheat is too severe to use for food, the wheat is pushed to sell as animal feed. To mitigate the economic losses of sprout damage, the wheat industry employs common practices. Early harvesting as soon as grains mature physically is generally recommended to farmers to avoid a risk of pre-harvest sprouting. When prolonged wet weather conditions are forecasted or expected in certain regions, batches of wheat received are subjected to testing to guarantee sound wheat. Depending on sprout severity, sprouteded wheat can be blended with sound wheat, but reducing the proportion of sprouted wheat requires progressively greater expenses because the starch hydrolyzing amylase activity in sprouted wheat increases exponentially as the sprout severity increases. As a result, blending severely sprouted wheat with sound wheat is a difficult and expensive remedy to improve end-use quality. Traditionally visual scoring is used for sprout count, but recently the secondary falling number test has been implemented at grain elevators for testing sprouted wheat. There is still a major problem with the reliability of falling number because many factors affect the result. To manage the sprouted wheat problem, the milling industry has often c