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ARS Home » Southeast Area » Stoneville, Mississippi » Crop Production Systems Research » Research » Publications at this Location » Publication #210269
Title: Surfactants Enhance Primisulfuron Activity in Common Lambsquarters (Chenopodium album L.)

Author
item SANYAL, D - UNIV OF MASSACHUSETTS
item Reddy, Krishna
item BHOWMIK, P - UNIV OF MASSACHUSETTS

Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 8/1/2007
Publication Date: 10/2/2007
Citation: Sanyal, D., Reddy, K.N., Bhowmik, P.C. 2007. Surfactants Enhance Primisulfuron Activity in Common Lambsquarters (Chenopodium album L.). Proceedings of 21st Asian Pacific Weed Science Society (APWSS) Conference, pp. 432-436.

Interpretive Summary: Effectiveness of surfactant on herbicidal activity varies with herbicide type and weed species. Common lambsquarters (Chenopodium album L.) is one of the most widely distributed weed species in the world and is competitive with 40 crops. Scientists from Department of Plant and Soil Sciences, University of Massachusetts and Southern Weed Science Research Unit, Stoneville, MS have conducted studies to determine the effect of non-ionic (Induce®) and organosilicone (Silwet L-77®) surfactants on primisulfuron activity and droplet contact angle on common lambsquarters and to examine the pattern of primisulfuron droplet spread on leaf surface. Both surfactants significantly reduced contact angles of primisulfuron droplets on common lambsquarters leaf surfaces. Silwet L-77® reduced the contact angle and increased the droplet spread more than Induce®. Primisulfuron activity was significantly enhanced by both surfactants. The increased activity of primisulfuron by the surfactants was due to lower contact angle and greater spread of spray droplets on leaf surface of common lambsquarters.

Technical Abstract: Common lambsquarters (Chenopodium album L.) is one of the most widely distributed weed species in the world and is competitive with 40 crops. Greenhouse and laboratory studies were conducted to determine the effect of non-ionic (Induce®) and organosilicone (Silwet L-77®) surfactants on primisulfuron activity and droplet contact angle on common lambsquarters and to examine the pattern of primisulfuron droplet spread on leaf surface using scanning electron microscopy. The activity of primisulfuron at 0, 20, 40, 60 and 80 g ai ha-1 was assessed 3 weeks after treatment in terms of percent injury and fresh weight. The contact angles of both sides of the 1-'l droplets on the leaf surface were measured using a goniometer. Primisulfuron activity on common lambsquarters in terms of percent injury and fresh weight was significantly enhanced by surfactant type and primisulfuron rates. There was no difference between the two surfactants in enhancing primisulfuron activity at all rates of primisulfuron. Both surfactants significantly reduced contact angles of primisulfuron droplets on common lambsquarters leaf surfaces. Silwet L-77® when mixed with primisulfuron had lowest contact angle on the leaf surface due to very low surface tension of the solution. Scanning electron micrographs showed that with Silwet L-77® the droplet spread was more and it gradually blended with the leaf cuticular surface. The increased activity of primisulfuron with the surfactants was related to the lower contact angle and greater spread of spray droplets on leaf surface of common lambsquarters.