Efficacy of the herbicide GF-2581 (penoxsulam + florasulam) against broadleaf weeds in olives

Abstract

Effective weed control in perennial crops is a challenge due to the limited availability of registered herbicides and herbicide resistance. The objective of the study was to evaluate the efficacy of the herbicide GF-2581 (penoxsulam + florasulam) on broadleaf weeds in comparison with other commonly used herbicides. Field trials were conducted in olives, in Etoloakarnania (Agrinio region) for two years (2012 and 2013). Efficacy assessments were made at 30, 60, 90 and 120 days after treatment. The GF-2581 formulation provided excellent control of a broad spectrum of broadleaf weed species. The long-term control of Sonchus oleraceous, Conyza canadensis and Stellaria media, provided by GF-2581 during the growing season was significantly greater than that using flumioxazin. When combined with glyphosate or diquat, the level of control of these three weeds was improved. The GF-2581 agent applied pre-emergence followed 14 days later by application of glyphosate provided 100% control in 2012. Lower efficacy levels were observed in 2013 and may have been the result of higher rainfall when compared to 2012. GF-2581 is an effective herbicide product to control broadleaf weeds, as a part of integrated weed control management strategies in olives.