Translator Disclaimer
1 November 2018 Application Timing and Degradation Rate of Sulfosulfuron in Soil Co-Affect Control Efficacy of Egyptian Broomrape (Phelipanche aegyptiaca) in Tomato
Amit Paporisch, Yael Laor, Baruch Rubin, Guy Achdari, Hanan Eizenberg
Author Affiliations +
Abstract

Egyptian broomrape (Phelipanche aegyptiaca Pers.) is a root-parasitic weed that severely damages many crops worldwide, including tomato (Solanum lycopersicum L.). In Israel, the management protocol used for P. aegyptiaca in open-field tomato includes PPI sulfosulfuron at 37.5 g ai ha − 1 to the top 10-cm soil layer. The objective of this study was to investigate the co-effect of sulfosulfuron application timing and variable degradation rate in soil on the control efficacy of P. aegyptiaca in tomato. Degradation of sulfosulfuron (80 ng g − 1 soil) at a temperature of 15 C, measured in soil samples from three farms using liquid chromatography–tandem mass spectrometry, followed a first-order kinetics with variable degradation rate constant among sites (0.008 to 0.012 d− 1). Incubation at 25 C increased sulfosulfuron degradation rate constant by a factor of 2 to 2.7 in soils from the different sites, with a similar degradation rate order among soils. A higher degradation rate in the soil resulted in a shorter period of residual activity, measured using a sorghum [Sorghum bicolor (L.) Moench.] bioassay. Phelipanche aegyptiaca management in open-field tomatoes was investigated in five independent field experiments. Sulfosulfuron soil concentration throughout the growing season (following preplant incorporation of 37.5 g ha − 1) was calculated from laboratorymeasured degradation rates, which were corrected to represent the effect of recorded temperatures at each field. At the end of the tomato growing season, control efficacy of P. aegyptiaca varied among experiments (70.4% to 100%) and positively correlated with predicted sulfosulfuron concentration at the critical period for seedling control (R2=0.67). The current study confirms that sulfosulfuron is degraded in soil to nonphytotoxic metabolites and that rapid degradation rates would result in reduced injury to P. aegyptiaca seedling and, consequently, lower control efficacy.

© Weed Science Society of America, 2018.
Amit Paporisch, Yael Laor, Baruch Rubin, Guy Achdari, and Hanan Eizenberg "Application Timing and Degradation Rate of Sulfosulfuron in Soil Co-Affect Control Efficacy of Egyptian Broomrape (Phelipanche aegyptiaca) in Tomato," Weed Science 66(6), 780-788, (1 November 2018). https://doi.org/10.1017/wsc.2018.49
Received: 14 March 2018; Accepted: 28 June 2018; Published: 1 November 2018
JOURNAL ARTICLE
9 PAGES


Share
SHARE
KEYWORDS
Egyptian broomrape
Parasitic weeds
persistence
residual herbicides
sulfonylurea
RIGHTS & PERMISSIONS
Get copyright permission
Back to Top