The effects of topical applications of glyphosate and aminotriazole on volunteer potatoes (Solanum tuberosum)

Abstract

Summary: Application of small amounts of glyphosate and aminotriazole to the top 2–3 leaves of potato stems killed those stems. Untreated stems attached to the same plant did not die, although they showed symptoms of herbicide damage. Glyphosate caused the death of the apices of the untreated stems, growth of axillary buds and sometimes aerial tuberization. Concentrations of glyphosate between 025 and 8% a.i. and of aminotriazole between 1 and 4% a.i. achieved equally good control of treated stems, although the higher concentrations worked more quickly and generally resulted in more symptoms on the untreated stems. The more stems that were treated on a particular plant, the greater the symptoms on the untreated ones. When all the stems were treated, no healthy tubers were produced; when only some were treated, both healthy and deformed tubers were found at harvest. The effects on the untreated stems are examined in relation to the translocation of glyphosate and the anatomy of the potato plant.