However, in the 2-year rotation, wheat yields are not always increased. The savings from reduced tillage almost equal the additional cost of herbicide treatment. The profit comes from increased yields and reduced erosion. An effective weed control program begins with the winter wheat crop. A good stand of vigorously growing winter wheat prevents weeds from becoming a problem following harvest.
Weeds are larger and harder to kill in poor stands of winter wheat.
However, wider row spacings are preferred in areas where there is more stubble and less rainfall. Barnyardgrass, foxtail species and field sandbur are especially troublesome in these wider spaced plantings in the higher rainfall areas. Farmers should make every effort to obtain uniform and vigorous stands of wheat. Poor stands and the lack of vigor are usually due to poor moisture management during the fallow period before winter wheat planting. Common purslane is especially troublesome.