Single and Multiple Resistance of Eleusine indica from Asahan Regency, Indonesia

Eleusine indica population at oil palm estate in the Asahan Regency has never been reported to being resistant to glyphosate and paraquat. This research was aimed to the resistance classification of E. indica population to glyphosate from one of oil palm estate in the Asahan Regency and to find out of glyphosate-resistant Eleusine (GRE) biotype has been also resistant to paraquat. This research was conducted on Weed Research Center Land, Faculty of Agriculture, Universitas Sumatera Utara, Medan from September 2017 until May 2018. Single resistance evaluation of E. indica population was performed using glyphosate at the dose 720 g a.i.ha-1. However the multiple resistance of GRE biotype was performed using paraquat at rates of 0, 50, 100, 200, and 400 g a.i.ha-1 and glyphosate at rates of 0, 720, 1440, 2880, and 5760 g a.i.ha-1. Susceptible-population (ESU-0) was taken at ball field of Politeknik Negeri Medan (Medan City) as a comparison. The data were analyzed by ANOVA and followed by Duncan test at level 5% using IBM SPSS Statistics software. The results showed that E. indica populations from one of oil palm estate in the Asahan Regency had survival of 81.48% (classified as glyphosate-resistant) and the dry weight of 24.35 g. Glyphosate at the dose 2880 g a.i.ha-1 and paraquat at the dose 200 g a.i.ha-1 were effectively (100%) controlled survival, tillers.pot-1, fresh weight.pot-1, dry weight.pot-1 and mortality of GRE biotype. The resistance index value of GRE biotype to glyphosate and paraquat of 4.91- and 1.26-fold, respectively compared to susceptible plants.