Integrated weed management strategies with cereal rye mulch in processing vegetable legumes

Authors: KORRES, NICHOLAS - Oak Ridge Institute For Science And Education (ORISE); Hausman, Nicholas; MOODY, JAMES - Retired ARS Employee; KITIS, EMRE - Akdeniz University; Williams, Martin

Submitted to: Agronomy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/23/2020
Publication Date: 10/19/2020
Citation: Korres, N.E., Hausman, N.E., Moody, J., Kitis, E., Williams II, M.M. 2020. Integrated weed management strategies with cereal rye mulch in processing vegetable legumes. Agronomy Journal. 112(5):4264-4275. https://doi.org/10.1002/agj2.20349.
DOI: https://doi.org/10.1002/agj2.20349

Interpretive Summary: The limited options of chemical weed control in processing vegetable legumes such as edamame, lima bean and snap bean necessitate the integration of tactics that satisfy weed management needs. The use of cereal rye as a cover crop, which was killed early i.e. four weeks prior to vegetable legume crops planting, in combination with various herbicide programs, augmented with hand-weeding, was investigated in a three-years field experiment for its weed control efficacy. The efficacy of early killed rye (EKR) compared to stale seedbed (SSB) was assessed through the density and biomass production of the naturally occurring weed flora along with crop establishment and yield, hand weeding and product recovery. EKR suppressed weeds through weed biomass reductions in edamame and snap bean crops but not in lima bean. All herbicide programs suppressed weed density and weed biomass in all vegetable legumes, especially when accompanied with hand-weeding, the inclusion of which enhanced weed suppression further. EKR did not compromise yield in edamame and increased product recovery in edamame and lima bean. The results presented in this study indicate the suitability of EKR as an integrated weed management component in edamame, the utility of which increases rapidly despite the limited weed control options that are available to the producers and processors.

Technical Abstract: Little is known about the potential benefits of cereal rye (Secale cereale L.) in combination with various weed management tactics in processing vegetable legume crops such as edamame, lima bean, and snap bean. Field experiments were conducted over three years to determine the extent to which early killed rye (EKR) and integrated weed management tactics, including pre- and post-emergence herbicides with (augmented) or without (standard) hand weeding, suppress the density and biomass of naturally occurring weed flora. Possible drawbacks on the crop establishment and yield also were investigated. EKR reduced weed biomass 53% and 73% compared to SSB in edamame and snap bean respectively. On the contrary, weed density and biomass increases of 67 and 39%, respectively, were observed in EKR, compared with SSB, in lima bean. Crop establishment and yield were unaffected by EKR in edamame; however, yield reductions were observed in lima bean and snap bean. Soil nitrate-nitrogen was negatively correlated with soil moisture in all vegetable legume crops tested. The application of pre- and post-emergence herbicides, particularly when followed by hand weeding, suppressed both weed density and biomass and improved yield. The results presented in this study indicate the suitability of EKR as an integrated weed management component in edamame.