Economic Evaluation of Field Bindweed (Convolvulus arvensis) Control in a Winter Wheat-Fallow Rotation

摘要

Field bindweed infests millions of hectares in the Great Plains greatly reducing productivity and value of land. The standard practice for field bindweed control is sweep tillage at 3 wk intervals combined with one or two annual 2,4-D applications during the 14 mo fallow period in a winter wheat-fallow crop rotation. This was compared to tillage and 2,4-D in conjunction with dicamba or a mixture of pi-cloram+2,4-D applied once during the first October of the first 14 mo fallow period. Also, three no-tillage systems were included using glyphosate+2,4-D at monthly intervals. Two of the treatments were supplemented with dicamba, or pi-cloram+2,4-D as in the sweep tillage system. All treatments controlled field bindweed in two fallow periods and two winter wheat crops, and increased winter wheat yields to about twice the control. Sweep tillage at 3 wk intervals combined with 2,4-D resulted in $36 ha~(-1) profit for an owner-operator compared to $15 ha~(-1) loss with no herbicide or tillage treatment. On average no-tillage lost $35 ha~(-1). Other treatments, although controlling field bindweed, lost from 35 to $186 ha~(-1). To determine if long-term benefit after control was achieved, average yields for the area were used to calculate profits using normal farming practices. Profits were 136, 78, and $-50 ha~(-1), respectively, for sweep tillage and 2,4-D, no-tillage, and the untreated check. In a standard 33:67 owner-tenant rental, profits to the owner for the control period were 90, -33, and $43 ha~(-1), respectively for tillage and 2,4-D, no-tillage, and untreated check. The tenant lost from $24 to 69 ha~(-1) for the three systems indicating owners must modify rental agreements during a field bindweed control program.