A COMPARISON OF MANAGEMENT REGIMES FOR ONE-YEAR ROTATIONAL SET-ASIDE WITHIN A SEQUENCE OF WINTER-WHEAT CROPS, AND OF GROWING WHEAT WITHOUT INTERRUPTION - 2 - EFFECTS ON VEGETATION AND WEED-CONTROL

Six management regimes for I-year set-aside were compared with continu ous winter wheat for their effects on weed control in two following te st crops of winter wheat. The experiment was repeated in each of three years (1989-91) on predominantly sandy loam soils in eastern England. The weed flora was dominated by Poa spp., Stellaria media, Matricaria spp., Chenopodium album and volunteer crops, predominantly wheat. Man aging set-aside by allowing natural regeneration and cutting it 2-4 ti mes during the growing season resulted in fewest weeds in the followin g wheat crop. It was also a low cost option. Winter wheat, despite the application of herbicides, was not as effective in minimizing weeds i n the winter wheat test crops as the best set-aside options. An Italia n ryegrass cover crop set seed despite being cut 2-4 times per year. T he only serious weed infestation arising in following wheat crops was from volunteer ryegrass in the second wheat following set-aside. The e ffects of management in the set-aside year were generally greater in t he second of the following wheats than in the first.