EFFECT OF WHEAT MORPHOLOGICAL STAGE AT GRAZING TERMINATION ON ECONOMIC RETURN

The economic impact of timing of grazing termination in the wheat (Tri ticum aestivum L.) grain-stocker cattle (Bos sp.) enterprise has not b een elucidated. A 4-yr study used the first hollow stem stage of growt h in ungrazed wheat as a grazing termination indicator and the subsequ ent effect on net return. First hollow stem is the stage at which holl ow stem can first be identified above the crown; it occurs prior to th e growing point reaching the soil surface. Net return was maximized wh en grazing was terminated at first hollow stem. Grain yield decreased (P < 0.05) 83 kg ha(-1) d(-1) as cattle grazed past first hollow stem. Increased weight gain by rattle was not sufficient to offset grain yi eld losses. Since hollow stem formation was delayed in grazed wheat, p roducers who use semidwarf wheat as a dual-purpose crop should monitor the morphological stage in ungrazed areas of the held to determine th e optimum time to terminate grazing.