Tillage Systems Influence Weed Seedbank Dynamics in Organic Vegetables
Applied Research
Dwayne Joseph
Agriculture Educator
University of Maryland
Chestertown
Abstract
Organic crop production practices that limit replenishment of the weed seedbank can reduce future weed pressure in vegetable systems. Cover cropping combined with conservation tillage can suppress weeds; however, reduced soil disturbance may also influence weed seedbank dynamics. A four-year study was conducted in a field transitioning to organic certification to evaluate how two conservation tillage systems (no-tillage, NT; strip-tillage, ST) and two conventional tillage systems (bare ground, BG; black polyethylene mulch, BP), used in combination with winter cover crops, affected the density and composition of the germinable weed seedbank in an eggplant and sweet corn rotation. Tillage system significantly influenced weed seedbank density, plant class (grass vs. broadleaf), and species composition. Germinable seedbank densities were consistently highest in NT and ST and lowest in BP, with BG intermediate. Broadleaf densities were greater in conservation tillage systems, while grasses were more abundant under conventional tillage. Goosegrass, carpetweed, yellow woodsorrel, and fall panicum accounted for more than 88% of the germinable seedbank across years, with relative abundances varying by treatment. Species richness increased over time in conservation tillage systems and was significantly greater in NT and ST by the final year. These results indicate that increased soil disturbance under conventional tillage reduces germinable weed seedbank density, whereas conservation tillage promotes greater species richness and shifts in dominant weed species, highlighting important tradeoffs for integrated weed management in organic vegetable production.
Poster has NOT been presented at any previous NACAA AM/PIC
This poster is being submitted for judging. It will be displayed at the AM/PIC if not selected as a State winner. The abstract will be published in the proceedings.
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Authors: Dwayne Joseph , Alan Leslie, Cerruti Hooks
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Joseph , D. Agriculture Educator, University of Maryland, Maryland, 21620
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Leslie, A. Center Director, University of Maryland, Maryland, 20742
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Hooks, C. Professor, University of Maryland, Maryland, 20742