Winter wheat (Triticum aestivum L.) grown as a dual‐purpose crop is a unique and economically important resource, especially in the southern Great Plains. Since the last major review of grazing effects on grain yield, in 1956, wheat cultivars have been developed that may affect the productivity of the grazing‐grain enterprise. Thus, we decided to review current research on grazing winter wheat and the effects on grain yield in light of earlier information. During a year of favorable precipitation and adequate to excess soil fertility, tall winter wheat cultivars grazed prior to jointing experienced increased grain yield relative to nongrazed wheat, because of reduced lodging. Current research suggests that the grain yield of semidwarf wheat cultivars is more sensitive to forage removal than for tall cultivars. Grazing termination dates necessary to prevent grain yield reduction of semidwarf cultivars also appear to be much earlier than for taller wheat cultivars. The reason for the difference in grazing tolerance is not clear; however, research suggests that semidwarf cultivars require maximum leaf area at anthesis for maximum grain yield. Tall wheat cultivars are not affected in the same manner, and decreased leaf area due to later grazing does not reduce grain yield of taller wheat cultivars to the same extent as for the semidwarf cultivars. Thus, taller wheat cultivars have the potential for extending the grazing period for livestock producers while producing grain yield similar to that of semidwarf wheat cultivars (which generally produce more grain in a nongrazed situation).

The use of winter wheat (Triticum aestivum L.) as a dual‐purpose forage and grain crop is important to the agricultural economies of the Southern Great Plains of the USA. Planting date is an important management factor in determining the economic success of a dual‐purpose winter wheat enterprise. The overall objective of the research reported in this paper is to determine the economic optimal planting date for dual‐purpose winter wheat production. The specific objectives are to determine wheat fall–winter forage yield, wheat grain yield, and wheat test weight response to planting date for dual‐purpose winter wheat production. Field studies were conducted in north central Oklahoma from 1991–1992 through 1999–2000. The impact of alternative planting dates on dual‐purpose wheat fall–winter forage yield, grain yield, and test weight was estimated. Estimated response functions illustrate that delaying the planting date from 10 to 30 September resulted in an 18% increase in expected grain yield, a 68% decrease in expected fall–winter forage yield, and only a 0.5% increase in expected test weight. Optimal planting date is sensitive to the relative value of wheat fall–winter forage and wheat grain, but not sensitive to wheat test weight discount schedules. When the value of wheat forage is high relative to the value of grain, it is more profitable to plant early to increase expected forage yield. Alternatively, when the value of grain is high relative to the value of forage, later planting generates greater net returns.

The economic impact of timing of grazing termination in the wheat (Triticum aestivum L.) grain‐stocker cattle (Bos sp.) enterprise has not been elucidated. A 4‐yr study used the first hollow stem stage of growth in ungrazed wheat as a grazing termination indicator and the subsequent effect on net return. First hollow stem is the stage at which hollow stem can first be identified above the crown; it occurs prior to the growing point reaching the soil surface. Net return was maximized when 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 cattle was not sufficient to offset grain yield losses. Since hollow stem formation was delayed in grazed wheat, producers who use semidwarf wheat as a dual‐purpose crop should monitor the morphological stage in ungrazed areas of the field to determine the optimum time to terminate grazing.

Aluminum (Al) toxicity is a major yield‐limiting factor in winter wheat production in many parts of the world. The use of Al‐tolerant cultivars reduces the impact of this problem and is common to the southern Great Plains where wheat is managed as a dual‐purpose crop. However, no quantitative data exist on the Al tolerance ranking of winter wheat cultivars often grown in a dual‐purpose management system. This study was established to classify on a field scale the Al tolerance of common winter wheat cultivars (Ok101, Ok102, 2137, 2174, Jagger, Jagalene, Custer, and AP502CL). Fall forage yield of each cultivar was harvested by hand clipping. Soil samples were collected at the same time and analyzed for pH and Al saturation (Alsat). Grain was hand‐harvested in June of each year from the same rows harvested for forage. Cultivar differences (P < 0.1) were found in forage and grain yields for the Alsat > 30% range. Al tolerance based on grain yield ranked as follows: 2137 > Jagalene = Ok101 > Jagger = 2174 ≥ Ok102 > Custer = AP502CL. Al tolerance based on forage yield ranking was similar to that of grain: 2137 > Ok101 = Jagalene = Jagger > 2174 = Ok102 > Custer = AP502CL. Grain yield seemed to be less affected by Alsat than forage yields. The use of Al‐tolerant winter wheat cultivars may minimize producers' risk of crop loss; therefore, this ranking of Al tolerance should help winter wheat producers make informed decisions if they have acid soils with high Al content and no other remedies available.

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