Optimizing buckwheat use as a weed suppressive cover crop for sustainable cropping systems in Florida

Project Overview

Project Type: Graduate Student
Funds awarded in 2007: $10,000.00
Projected End Date: 12/31/2009
Grant Recipient: University of Florida
Region: Southern
State: Florida
Graduate Student:
Major Professor:
Dr. Carlene Chase
University of Florida

Annual Reports


Not commodity specific


  • Crop Production: cover crops
  • Pest Management: allelopathy, competition, cultural control, physical control, weed ecology


    Buckwheat is a promising cover crop for weed management in sustainable and organic cropping systems. Since the humid, subtropical climate in Florida is different considerably from the temperate areas of the country where buckwheat is typically grown, recommendations were needed for growing buckwheat cover crop to maximize its benefits. Buckwheat cover crop was compared with weedy fallow and a harrowed control at six planting dates in spring and fall in 2007 and 2008. Generally, buckwheat resulted in fewer weeds than the weedy fallow and was as effective at suppressing weeds as the harrowed control. With the mild weather in spring and fall in north-central Florida, climatic conditions at the beginning of May and mid October may be the most suitable for buckwheat growth and weed suppression. When termination practices of rolling, flail mowing, light tillage, and the combination of flail mowing and light tillage were compared, light tillage may be a promising option for buckwheat planted in fall. Rolling and flail mowing may be more applicable for use in spring and for systems in which growers wish to retain buckwheat residue as an organic mulch.


    Weed management in horticultural production can be a major challenge in conventional, transitional, and organic production systems. In conventional systems, herbicide options are often limited and can be harmful to rotational crops. In transitional and organic systems nonsynthetic herbicides may be used if nonchemical approaches are insufficient. However, nonsynthetic herbicides are costly and thus far are all nonselective and can injure the crop. Efficacy and persistence of control with nonsynthetic herbicides are often insufficient. Cover crops could be used as an alternative to herbicides and as a part of an integrated weed management program to control weeds in conventional production systems and decrease the need for hand-weeding and cultivation in organic systems. Both living cover crops and cover crop residues can interfere with weed seed germination and seedling emergence.

    Buckwheat [Fagopyrum esculentum Moench] is an annual broadleaf grain crop belonging to the Polygonaceae family and is generally utilized as a summer cover crop in temperate areas. It can be used as a weed-suppressive cover crop based on mechanisms of competition with weeds for resources, alteration of the soil physical environment, and allelopathy. To obtain the optimal growth for best benefits, it should be planted in cool and moist environments without frost and drought.

    Cover crops can be terminated with chemicals or mechanically. Cover crop residues can be incorporated into the soil or retained on the surface of the soil as mulches. The effectiveness of termination practices may differ depending on the growth stage and species of the cover crops. Moreover, termination practices can also affect weed emergence and growth.

    Since the humid subtropical climate of Florida is considerably different from the rest of the country, recommendations for cover crop utilization developed in other parts of the US may not be applicable. Termination practices may influence weed emergence and growth through soil disturbance or mulches or by allelopathy, whereas they may also affect residue decomposition and the persistence of the surface mulch or allelopathic effect. Therefore, the goal of this study was to generate information on planting period and termination practices for buckwheat to determine whether it can be a useful cover crop to suppress weeds effectively for sustainable and organic cropping systems in north central Florida.

    Project objectives:

    1. To determine the optimal planting period for buckwheat as a weed suppressive cover crop in Florida.

      To compare methods for termination of buckwheat when used as a cover crop for weed suppression in Florida.

    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.