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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #184785
Title: YELLOW NUTSEDGE (CYPERUS ESCULENTUS) CONTROL WITH METHAM-SODIUM IN TRANSPLANTED CANTALOUPE (CUCUMIS MELO)

Author
item Johnson, Wiley - Carroll
item MULLINIX, JR., BENJAMIN - UNIVERSITY OF GEORGIA

Submitted to: Crop Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/21/2006
Publication Date: 4/2/2007
Citation: Johnson, W.C., Mullinix, Jr., B. 2007. Yellow nutsedge (Cyperus esculentus) control with metham-sodium in transplanted cantaloupe (Cucumis melo). Crop Protection. 26:867-871.

Interpretive Summary: Metham-sodium has been identified as an alternative to methyl bromide fumigation for perennial nutsedge control in transplanted cucurbit crops. However, questions persist regarding the optimum combination of preplant fumigation interval, metham-sodium rate, and seedbed mulching for maximum efficacy. Trials were conducted in Tifton, GA from 2001 to 2003 to evaluate all possible combinations of preplant fumigation intervals (1-wk, 2-wk, or 3-wk before transplanting), three metham-sodium rates (nontreated, 2x rate, and 1x rate), and polyethylene mulching (bareground or black polyethylene mulched seedbeds). Metham-sodium sprayed and incorporated 2-wk before transplanting effectively controlled yellow nutsedge, with minimal fumigant phytotoxicity to cantaloupe. In contrast, metham-sodium fumigation 3-wk before transplanting was not as effective in controlling yellow nutsedge as fumigation closer to transplanting. Black polyethylene mulch improved yellow nutsedge control and increased cantaloupe yield compared to bareground seedbeds. Plots fumigated with metham-sodium at the 1x rate had greater yield than either non-fumigated plots or plots treated with metham-sodium at the 2x rate. Cantaloupe yield response was attributed to superior yellow nutsedge control. These results show that a 1x rate of metham-sodium sprayed and incorporated 2- to 3-wk before transplanting, with seedbeds immediately covered with black polyethylene mulch, is a cost-effective alternative to methyl bromide fumigation for perennial nutsedge control.

Technical Abstract: Irrigated field trials were conducted from 2001 through 2003 in Georgia at the Coastal Plain Experiment Station to determine the optimum combination of preplant fumigation interval, metham-sodium rate, and polyethylene mulching for yellow nutsedge control in transplanted cantaloupe. The trial evaluated all possible combinations of preplant fumigation intervals (1-wk, 2-wk, or 3-wk before transplanting), three metham-sodium rates (nontreated, 2x rate, and 1x rate), and polyethylene mulching (bareground or black polyethylene mulched seedbeds). Metham-sodium sprayed and incorporated 2-wk before transplanting effectively controlled yellow nutsedge, with minimal fumigant phytotoxicity. Metham-sodium applied 1-wk before transplanting provided acceptable yellow nutsedge control, but stunted cantaloupe. In contrast, metham-sodium fumigation 3-wk before transplanting was not as effective in controlling yellow nutsedge as fumigation closer to transplanting. Polyethylene mulch improved yellow nutsedge control and increased yield across all possible combinations of preplant fumigation intervals and metham-sodium rates. Plots fumigated with metham-sodium at the 1x rate had better yellow nutsedge control and greater yield than either non-fumigated or treated with metham-sodium at the 2x rate. Cantaloupe yield response was attributed to superior yellow nutsedge control across all mulching treatments provided by the 1x rate. Polyethylene mulch applied immediately prior to transplanting suppressed yellow nutsedge emergence without fumigation, giving transplanted cantaloupe the opportunity to shade seedbeds before weed emergence.