Glyphosate‐resistant Lolium multiflorum in Chilean orchards

• DOI: 10.1046/j.1365-3180.2003.00311.x
• Publication Date: 2003-03-12T23:52:35Z
• Authors: A Perez; M Kogan
• Keywords: Lolium multiflorum; Lolium rigidum; Orchard; Petri dish

Summary Lolium multiflorum (Italian ryegrass) seeds suspected of being resistant to glyphosate were collected from fruit orchards at two locations, San Bernardo (SB) and Olivar (OL), Chile, that had been treated an average three times per year with the isopropylamine salt during previous 8–10 years. Laboratory experiments conducted for each orchard population a susceptible population, commercial cultivar called Tama (TM), using Petri dishes containing filter paper saturated 5 mL solution (0–160 mg a.e. L −1 ). Pot dose–response also in greenhouse. The L. populations (0.00–4.32 kg ha dose needed reduce shoot length (Petri dish experiment) fresh weight (pot by 50% was determined population. Compared TM experiment found SB OL five‐ sixfold, respectively, more glyphosate, whereas pot two‐ fourfold, glyphosate. These results confirm new case resistance novel species, , correspond first reported South America.