| Field, greenhouse, and laboratory experiments were conducted in 2014 and 2015 to evaluate effects of glyphosate drift on 'Red Norland' potato (Solanum tuberosum L.) grown for commercial and seed industries. Glyphosate drift was simulated by applying sub-lethal doses during the growth stages of tuber initiation (TI), early tuber bulking (EB), and late tuber bulking (LB). Sub-lethal glyphosate doses applied to mother plants had the greatest effect on daughter tubers during TI, resulting in high tuber sets and increased unmarketable tubers. Glyphosate applied to mother plants resulted in residue in the daughter tubers. When these tubers were used as seed, glyphosate doses at EB and LB resulted in decreased progeny emergence and vigor. The presence of glyphosate residue in tubers used for seed was confirmed through an enzyme-linked immunosorbent assay. Precautions should be taken to avoid glyphosate contamination of 'Red Norland' mother plants to prevent unmarketable tubers and poor quality seed. |
