Use of Wild Radish (Raphanus raphanistrum) and Rye Cover Crops for Weed Suppression in Sweet Corn

• Published in: Weed science Vol. 56; no. 4; pp. 588 - 595
• Main Authors: Malik, Mayank S., Norsworthy, Jason K., Culpepper, A. Stanley, Riley, Melissa B., Bridges, William
• Format: Journal Article
• Language: English
• Published: 810 East 10th Street, Lawrence, KS 66044-8897 Weed Science Society of America 01-07-2008; Cambridge University Press
• Subjects: allelochemicals; Allelopathy; application rate; atrazine; Biological and medical sciences; Chemical control; Corn; Cover crops; crop yield; field experimentation; Fundamental and applied biological sciences. Psychology; Glucosinolates; Herbicides; integrated weed management; IWM; metolachlor; Parasitic plants. Weeds; pesticide application; Phytopathology. Animal pests. Plant and forest protection; plant density; Plants; preemergent weed control; Radishes; Raphanus raphanistrum; reduced herbicide rates; Rye; Secale cereale; sweetcorn; Tillage; Weed control; Weed Management; Weeds; Zea mays; South Carolina; Georgia; reduced herbicide rates; Allelopathy; cover crops; large crabgrass, Digitaria sanguinalis (L.) Scop. DIGSA; sweet corn, Zea mays L. ‘Silver Queen’, ‘Summer Sweet’, ‘Prime Plus’; ivyleaf morningglory, Ipomoea hederacea Jacq. IPOHE; S-metolachlor; glucosinolates; wild radish Raphanus raphanistrum L. RAPRA; spreading dayflower, Commelina diffusa Burm. f. COMDI; Florida pusley, Richardia scabra L. RCHSC; rye, Secale cereale L. ‘Wrenz’; IWM; Atrazine; Monocotyledones; Glucosinolate; Cover crop; Cereal crop; Cruciferae; Gramineae; Reduced rate protection; Dicotyledones; Weed science; Angiospermae; Thioglycoside; Carbohydrate; Secale cereale; Weed; Sulfur Organic compounds; Biochemical compound; Use; Zea mays var. saccharata; Pesticides; Oside; Herbicide; Restrictive practice; Application rates; Vegetable crop; Spermatophyta; Heteroside; Chemical weed control; Raphanus raphanistrum
• ISSN: 0043-1745; 1550-2759
• DOI: 10.1614/WS-08-002.1

Field experiments were conducted near Blackville, SC, and Tifton, GA, in 2004 and 2005, to evaluate the effect of wild radish and rye cover crops on weed control and sweet corn yield when used in conjunction with lower-than-recommended herbicide rates. Cover crop treatments included wild radish, rye, and no cover crop, alone and in conjunction with half and full rates of atrazine (0.84 and 1.68 kg ai ha−1) plus S-metolachlor (0.44 and 0.87 kg ai ha−1) applied before sweet corn emergence. Florida pusley, large crabgrass, spreading dayflower, ivyleaf morningglory, and wild radish infested the test sites. Wild radish and rye cover crops without herbicides reduced total weed density by 35 and 50%, respectively, at 4 wk after planting (WAP). Wild radish in conjunction with the full rate of atrazine plus S-metolachlor controlled Florida pusley, large crabgrass, and ivyleaf morningglory better than rye or no cover crop treated with a full herbicide rate in 2004 at Blackville. In 2005, at Blackville, weed control in sweet corn following wild radish cover crop plots alone was not different from that following rye. Wild radish or rye in conjunction with a half or full rate of atrazine and S-metolachlor controlled > 95% Florida pusley, wild radish, and large crabgrass in sweet corn at Tifton during both years. Ten glucosinolates, potential allelopathic compounds, were identified in wild radish, including glucoiberin, progoitrin, glucoraphanin, glucoraphenin, glucosinalbin, gluconapin, glucotropaeolin, glucoerucin, glucobrassicin, and gluconasturtin. Sweet corn yields at Blackville and Tifton following wild radish or rye cover crops were similar between the half and full rates of atrazine plus S-metolachlor. Sweet corn in wild radish or rye cover crop plots without herbicides produced less-marketable ears than herbicide-treated plots, indicating that a combination of cover crops and herbicides are required to optimize yields and to obtain desirable weed control. Nomenclature: Atrazine; S-metolachlor; Florida pusley, Richardia scabra L. RCHSC; ivyleaf morningglory, Ipomoea hederacea Jacq. IPOHE; large crabgrass, Digitaria sanguinalis (L.) Scop. DIGSA; spreading dayflower, Commelina diffusa Burm. f. COMDI; wild radish Raphanus raphanistrum L. RAPRA; rye, Secale cereale L. ‘Wrenz’; sweet corn, Zea mays L. ‘Silver Queen’, ‘Summer Sweet’, ‘Prime Plus’.