Efficacy and Tolerance to HPPD-Inhibiting Herbicides in Sweet Corn

• Published in: Weed technology 2008-10, Vol.22 (4), p.666-674
• Main Authors: Bollman, Joseph D, Boerboom, Chris M, Becker, Roger L, Fritz, Vince A
• Format: Article
• Language: English
• Subjects: Abutilon theophrasti; adverse effects; Ambrosia artemisiifolia; broadleaf weeds; Chenopodium album; Corn; cultivars; grass weeds; Growth retardation; Herbicide resistance; Herbicides; Hybridity; Hypochromic anemia; Injury; mesotrione; metolachlor; nontarget organisms; Petroleum; plant damage; postemergent weed control; Prairies; preemergent weed control; Rotating generators; sensitivity; Setaria faberi; sweetcorn; tembotrione; topramezone; Weed control; Weed Management-Other Crops/Areas; yield; Zea mays
• ISSN: 0890-037X; 1550-2740
• DOI: 10.1614/WT-08-036.1

The use of POST herbicides has been limited in sweet corn because of the narrow spectrum of weed control or potential crop injury. Field experiments were conducted to evaluate the 4-hydroxyphenyl pyruvate dioxygenase (HPPD)-inhibiting herbicides mesotrione, tembotrione, and topramezone applied POST in sweet corn at three locations. Efficacy of mesotrione, tembotrione, and topramezone applied alone or mixed with atrazine was compared to other labeled POST herbicides following PRE S-metolachlor. Giant foxtail control was greater with tembotrione or topramezone than mesotrione alone or mixed with atrazine. Common lambsquarters, velvetleaf, and common ragweed were controlled 98% or greater with the HPPD-inhibiting herbicides when mixed with atrazine. Tolerance of six sweet corn hybrids was determined in the field when treated with 1× and 2× rates of these herbicides mixed with atrazine. Tolerance of six sweet corn hybrids to these herbicides was determined in the greenhouse when treated with 0.5, 1, 2, 4, 8, and 16 times the labeled rate. Differential hybrid tolerance to each herbicide was observed in both the field and greenhouse evaluations. Tembotrione killed ‘Merit’ in both evaluations. Excluding Merit, hybrids generally had good tolerance to tembotrione and topramezone in the field, but had differential tolerance to mesotrione. With the exception of Merit, hybrids generally had greater tolerance to tembotrione than topramezone and less tolerance to mesotrione in the greenhouse. These HPPD-inhibiting herbicides provide POST weed control, but the potential for sweet corn injury varies among the herbicides and hybrids and warrants further characterization. Nomenclature: Atrazine; mesotrione; S-metolachlor; tembotrione; topramezone;common lambsquarters, Chenopodium album L. CHEAL; common ragweed, Ambrosia artemisiifolia L. AMBEL; giant foxtail, Setaria faberi Herrm. SETFA; velvetleaf, Abutilon theophrasti Medicus ABUTH; corn, Zea mays L