Response of multiple seeded cocklebur and other cocklebur types to herbicide treatment

• Published in: Pest management science Vol. 61; no. 7; pp. 643 - 648
• Main Authors: Abbas, Hamed K, Johnson, Bobbie J, Pantone, Dan J, Wax, Loyd M, Hine, Ron, Shier, W Thomas
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.07.2005; Wiley; Wiley Subscription Services, Inc
• Subjects: Alternaria - physiology; Alternaria helianthi; Arsenicals - pharmacology; Biological and medical sciences; biological control; chemical control; cocklebur biotype; common cocklebur; formulation; Fundamental and applied biological sciences. Psychology; Herbicides; Imidazoles - pharmacology; multiple seeded cocklebur; Nicotinic Acids - pharmacology; Parasitic plants. Weeds; Pest Control, Biological; Phytopathology. Animal pests. Plant and forest protection; Pyrimidines - pharmacology; Quinolines - pharmacology; Seeds; Species Specificity; Sulfonylurea Compounds - pharmacology; Weeds; Xanthium; Xanthium strumarium; United States; North America; America; Texas; Weed; common cocklebur; Treatment efficiency; Biological control; Pesticides; Alternaria helianthi; Compositae; cocklebur biotype; Microbial herbicide; Herbicide; Xanthium strumarium; multiple seeded cocklebur; Fungi; Dicotyledones; Angiospermae; Biotype; formulation; Spermatophyta; Fungi Imperfecti; Biopesticide; chemical control; Thallophyta; Chemical weed control
• ISSN: 1526-498X; 1526-4998
• DOI: 10.1002/ps.1033

Multiple seeded cocklebur has been found in the last decade in Texas, and described as a biotype of Xanthium strumarium L with up to 25 seeds per bur instead of the usual two. The multiple seeded bur typically produces up to nine seedlings, causing concern that it may be harder to control than normal seeded common cocklebur. The efficacies of a series of fungal and conventional commercial herbicides have been compared in the greenhouse on seedlings of multiple seeded cocklebur from Texas (MSC‐TX) and normal common cockleburs from Texas (NCC‐TX), Arkansas (NCC‐AR), Illinois (NCC‐ILL) and two from Mississippi (NCC‐MS#1, NCC‐MS#2). Three measures of herbicidal activity (reductions in plant height and dry weight, and mortality) were used. The fungal herbicide Alternaria helianthi (Hansf) Tubaki & Nishihara at 1 × 105 conidia ml−1 + 2 g liter−1 Silwet L‐77 with an 8‐h dew period was an effective herbicide with all biotypes, as were the commercial chemical herbicides chlorimuron (14.8 g ha−1), imazaquin (29.6 g ha−1), sodium hydrogen methylarsonate (MSMA; 279.1 g ha−1) and imazethapyr (39.5 g ha−1). The membrane‐disrupting organic arsenical MSMA was effective with all biotypes, whereas commercial chemical herbicides which act by inhibiting branched‐chain amino acid synthesis (chlorimuron, imazaquin and imazethapyr) were less effective against normal seeded common cocklebur biotypes with short stature. These studies showed that multiple seeded cocklebur was at least as susceptible to the biological agent A helianthi and to the conventional commercial herbicides studied as were normal seeded cockleburs, suggesting that existing methods should be adequate to control this novel biotype. Copyright © 2005 Society of Chemical Industry