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Weed control in farm woodlands - WD0107

Description
Previous research and experience of Farm Woodland Scheme (and FWPS) plantings has identified weed control as a key problem inhibiting the successful establishment of farm woodland trees. Recent research within Project WD0101 has clearly demonstrated the efficacy and persistence of certain triazine herbicides, most notably Gardoprim A (atrazine + terbuthylazine); however, due to perceived environmental risks and the commercial decisions of chemical manufacturers, use of many of the triazine-based products is no longer an option. Further research is required to examine the merits of a range oaf alternative methods of weed control for farm woodland plantations. As well as non-trazine residual herbicides, options such as mulching tree rows with organic waste materials, including straw and farm-yard manure, should be considered.

The woodland Grant Scheme and Farm Woodland Premium Scheme both allow trees to be planted at spacing s up to 3 x 3 m. This gives tree densities well below those traditionally recommended for forest planting. Planting trees at such wide spacing cuts the cost of woodland establishments, without a loss of grant-aid, and also permits use of farm machinery and allows relatively easy woodland maintenance. Despite these undoubted benefits, wide spacing of trees will allow greater development of side-branches on the lower stem of trees - increasing knottiness and decreasing the value of the timber produced. Where timber production is seen as an objective, the silvicultural problem might be overcome by early pruning of side branches, `cleaning` the lower stem of young trees, commencing perhaps 3 to 5 years after planting.
Objective
To study the safety and efficacy of a range of non-triazine residual herbicides when used for weed control in recently planted farm woodlands, and to compare these chemicals with a highly effective triazine mixture. To examine the effectiveness of organic mulches, including farm waste materials such as straw and farm-yard manure, in controlling weed growth around trees. To complete a preliminary assessment of the feasibility of mechanical application of farm-yard manure into tree rows. To examine the effects of a range of pruning treatments, designed to improve the final timber value of trees planted at relatively wide spacing, on the growth and habit of young broadleaved trees. To produce initial recommendations on the feasibility of hand pruning of young trees as a technique for improvement of tree form, giving due regard to the relative costs of pruning operations and higher density planting.
Time-Scale and Cost
From: 1993

To: 1997

Cost: £75,000
Contractor / Funded Organisations
ADAS UK Ltd.
Keywords
              
Fields of Study
Farm Woodlands