Author
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Webster, Theodore |
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Submitted to: Weed Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/3/2005 Publication Date: 11/1/2005 Citation: Webster, T.M. 2005. Mulch type affects growth and tuber production of yellow nutsedge (Cyperus esculentus) and purple nutsedge (Cyperus rotundus). Weed Science. 53:834-838. Interpretive Summary: Methyl bromide has been the foundation for pest management in vegetable crop production in the southeast US. However, methyl bromide use will be abolished in 2005. Many of the proposed fumigant alternatives may only be short-term replacements due to potential regulatory issues. Nutsedges are the most troublesome weeds of vegetable crops in Southern US. In many vegetable crops, effective long-term alternatives to methyl bromide for nutsedge management have not been identified. Polyethylene mulch is commonly used in vegetable production. However, nutsedges penetrate mulch and compete with crops for resources. Studies evaluated the effect of black and clear mulch on nutsedge growth and tuber production relative to non-mulched control over a 16 week period. Relative to non-mulched, yellow nutsedge shoot production was reduced 46 to 72% by black and clear mulch. Yellow nutsedge shoot numbers that pierced and emerged through black and clear mulches wee reduced 96% relative to nonmulched. Yellow nutsedge tuber production was reduced 49 to 51% in black and clear mulch. Growth of purple nutsedge shoots and tubers in black mulch was similar to non-mulched. Clear mulch reduced purple nutsedge tuber biomass relative to non-mulched, but clear mulch was similar to black mulch in nearly all measured variables. The relative insensitivity of purple nutsedge and sensitivity of yellow nutsedge growth to the physical mulch barrier, could lead to a shift in nutsedge species composition in mulched vegetable production. Technical Abstract: Polyethylene mulch is an effective component of weed management in commercial vegetable production, but nutsedges persist and proliferate in these systems. Studies evaluated growth and tuber production of purple and yellow nutsedge grown in pots covered with black-opaque polyethylene mulch, clear-colorless polyethylene mulch, or non-mulched. Single nutsedge tubers wee planted and growth evaluated over a 16 week period. Relative to non-mulched, yellow nutsedge shoot production was reduced 46 to 72% by black and clear mulch. Yellow nutsedge shoot number that pierced and emerged through black and clear mulches was reduced 96% relative to emerged shoots in non-mulched. Yellow nutsedge in non-mulched produced 366 tubers per initial tuber, while tuber production was reduced 49 to 51% in black and clear mulch. Growth of purple nutsedge shoots and tubers in black mulch was similar to non-mulched. Clear mulch reduced purple nutsedge tuber biomass relative to non-mulched, but clear mulch was similar to black mulch in nearly all measured variables. Without mulch, yellow nutsedge produced more shoots, shoot biomass, tubers, tuber biomass, and root biomass than purple nutsedge. However, growth of yellow nutsedge was hindered by mulch, while differences in purple nutsedge growth among mulches could not be detected. The relative insensitivity of purple nutsedge and sensitivity of yellow nutsedge growth to the physical mulch barrier, could lead to a shift in nutsedge species composition in mulched vegetable production. |
