Improving Nutsedge and Grass Control in Organic Production Systems Using Sequential Mowing and Organic Herbicide Application

Project Overview

Project Type: Graduate Student
Funds awarded in 2021: $15,654.00
Projected End Date: 08/31/2024
Grant Recipient: North Carolina State University
Region: Southern
State: North Carolina
Graduate Student:
Major Professor:


Not commodity specific


  • Pest Management: chemical control, physical control, weed ecology
  • Production Systems: organic agriculture

    Proposal abstract:

    Yellow (Cyperus esculentus) and purple nutsedge (Cyperus rotundus)] are ranked the 6th most troublesome weeds in vegetable and fruit crops and soybean, and cotton in the U.S. (VanWychen 2019).  These nutsedge species and annual grasses including large crabgrass (Digitaria sanguinalis) and goosegrass (Eleucine indica) are difficult to control in organic systems including plasticulture, and no-till systems. In organic systems, no organic herbicide options are registered for controlling nutsedge species, and organic herbicides provide little to no control of annual grasses.   These weeds are primarily controlled by hand weeding and cultivation in organic systems. Continuous cultivation is detrimental to soil health, promotes soil erosion, and reduces organic content in the soil. In turfgrass, mowing is commonly used as a means of controlling perennial nutsedge by depleting their tubers with repeated mowing (Summerlin and Coble 2000).   Preliminary evaluations suggest an application of an organic herbicide applied immediately after mowing may improve weed control, as well as reduce the number of mowings required to inhibit nutsedge tuber production (Ippolito, unpublished data). To reduce tillage and improve weed control, studies will be conducted to determine the effect of subsequent mowing in conjunction with organic herbicide applications on nutsedge (yellow and purple), large crabgrass and goosegrass control.   Additionally, the impact of these treatments on the weed seedbank will be determined.

    Project objectives from proposal:


    1. Develop a nutsedge and annual grass management program utilizing subsequent mowing and organic herbicide application.
    2. Determine the optimum program of sequential mowing and organic herbicides to reduce weed seedbank composition and seed density.
    3. Determine the effects of organic herbicide rate in combination with mowing to identify optimal herbicide rate for perennial nutsedge and annual grass control.
    4. Disseminate information, knowledge and recommendations through grower meetings, extension articles, and refereed journal publications.
    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.