Submitted to: American Society of Agronomy
Publication Type: Abstract Only
Publication Acceptance Date: 10/31/1999
Publication Date: N/A
Citation: MACKOWN, C.T., CARVER, B.F. 1999. SOURCE-SINK INTERACTIONS OF WHEAT CULTIVARS USED FOR GRAZING AND GRAIN PRODUCTION. AMERICAN SOCIETY OF AGRONOMY. Abstract p. 151. Interpretive Summary: Abstract only
Technical Abstract: In a preliminary experiment, grain yield of 2163 hard red winter wheat (HRWW, Triticum aestivum L.) grown for forage-plus-grain was 18% less (P=0.08) than wheat grown for grain only. Aboveground biomass of this grazed cv was 60% less (P=0.001) and grain protein concentration was 9% (P=0.003) less than that of ungrazed wheat. To further test our hypothesis sthat grazing reduces the source-sink ratio and alters assimilate availability thereby affecting grain traits, we expanded our experiment to include 12 HRWW released within the past 60 years. Overall, grazing significantly (P<0.05) reduced the dry weight of the flag leaf blade at anthesis by 24%, total aboveground biomass at maturity 25%, spike number 17%, kernel mass 7.0%, grain yield 26%, and grain N concentration 5.8%. Apparently, greater aboveground biomass of ungrazed wheat had a greater reservoir of N available for redistribution to the grain.