Author
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Teasdale, John |
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Submitted to: Weed Science Society of America Meeting Abstracts
Publication Type: Abstract Only Publication Acceptance Date: 9/9/2003 Publication Date: 3/1/2004 Citation: Teasdale, J.R. 2004. Interactions between weed seedling recruitment, surface residue, and soil-based weed management practices [abstract]. Weed Science Society of America Meeting Abstracts No. 146 [CDROM]. 44:42. Interpretive Summary: Technical Abstract: Use of no-tillage cropping systems can result in the presence of crop and/or cover crop residue on the surface of soils during the time of crop and weed establishment. Research during the past decade has demonstrated the selective impact that residue can exert on recruitment of various weed species. Residue can either inhibit or stimulate recruitment depending on the amount of residue present and local environmental conditions. Mechanisms for inhibition of emergence include modification of environmental cues that trigger germination, allelopathic inhibition of germination and/or emergence processes, and physical interference with emergence and establishment of seedlings. Physical properties of a surface mulch that define the suppression of weed emergence regardless of residue type are mulch area index (surface area of mulch material per unit soil area) and solid volume fraction (fraction of mulch volume composed of solid material). Recent research has shown that surface residue can interfere with seedling mortality resulting from both herbicidal and mechanical weed management practices. Surface residue adsorbs and reduces soil solution concentrations of common soil-applied herbicides such as metolachlor and atrazine and can be antagonistic to the activity of these herbicides. Residue also interferes with mechanical cultivation and reduces the efficiency of seedling disruption by mechanical implements. Therefore, although surface residue can be used to reduce seedling recruitment in weed management systems, it also can reduce the efficiency of soil-based weed management practices such as preemergence herbicides and mechanical cultivation. Novel approaches are needed to create synergisms between surface residue and other "little hammers" that may not adequately control weeds alone. |
