Studies on the Absorption, Residues and Metabolism of Cyromazine in Tomatoes

The residues and metabolism of radio‐labeled cyromazine (N‐cyclopropyl‐1,3,5‐triazine‐2,4,6‐triamine) formulated as a 750 g kg−1 WP (‘Trigard’ 75WP)™ was studied in greenhouse tomatoes. Residues of cyroma‐zine and its metabolites were remarkably persistent, with only a slight loss occurring within a 30‐day period. Findings with tomatoes were similar to those with glass plates when exposed to cyromazine. Little volatilization occurred from either tomato or glass surfaces kept under greenhouse conditions. The only metabolite identified was melamine on both glass plates and tomatoes. Two other metabolites were found but were not identified.