A review of weed management challenges in organic peanut production

Authors: Johnson, Wiley - Carroll

Submitted to: Peanut Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/28/2019
Publication Date: 3/1/2019
Citation: Johnson, W.C. 2019. A review of weed management challenges in organic peanut production. Peanut Science. 46(1):56-66. https://doi.org/10.3146/PS18-12.1.
DOI: https://doi.org/10.3146/PS18-12.1

Interpretive Summary: Organic peanut production is a risky enterprise and this is largely due to difficulties in managing weeds using systems acceptable for certified organic production. In contrast with conventional peanut production that relies on conventional herbicides for weed control, organic peanut production relies on an integrated system of cultural, mechanical, chemical, and thermal weed control. The foundation for an integrated weed management system is cultural weed control that is a series of production practices that promote peanut growth to suppress weeds. Cultural weed controls include a uniform peanut stand planted in rows 91 cm wide at a density of 20 to 26 plants/m of row. These practices promote vigorous early season peanut growth and lessen chances for weed escapes. Mechanical weed control is based on intensive cultivation using a tine weeder and sweep cultivator to control weeds before they emerge. Handweeding is also a form of mechanical weed control that is used to supplement other weed control efforts by controlling sparse populations of escapes. Herbicides derived from natural products and thermal weed control using propane flaming have limited value in organic peanut production due to limited weed control spectra, particularly poor control of annual grasses and perennial weeds. Successful weed management in certified organic peanut production will depend on an integrated system, not a single form of weed control.

Technical Abstract: Organic peanut production is a high-risk cropping system and ~ is largely due to difficulties in managing weeds using systems acceptable for certified organic production. In contrast with conventional peanut production that relies on synthetic herbicides for weed control, organic peanut production relies on an integrated system of cultural, mechanical, chemical, and thermal weed control. The foundation for an integrated weed management system is cultural weed control that is a series of production practices that promote peanut growth to suppress weeds. Cultural weed controls include a uniform peanut stand of 20 to 26 plants/m of row and vigorous early season growth. Mechanical weed control is based on intensive cultivation regimes with a tine weeder and sweep cultivator to control weeds before they emerge. Handweeding is also a form of mechanical weed control that is used to supplement other weed control efforts by controlling sparse populations of escapes. Herbicides derived from natural products and thermal weed control using propane flaming have limited value in organic peanut production due to limited weed control spectra, particularly poor control of annual grasses and perennial weeds. Despite these limitations, naturally derived herbicides and propane flaming may have specialized niches to control broadleaf weeds. Successful weed management in certified organic peanut production will depend on an integrated system, not a single form of weed control.