Pesticide residues in bee products collected from cherry trees protected during blooming period with contact and systemic fungicides

摘要

Fungicide (vinclozolin, iprodione and methyl thiophanate [thiophanate-methyl]) residues were determined in honey, pollen and bee bread from a plantation of cherry (Prunus cerasus) cv. English morello. The least contaminated were honey samples, whichcontained up to 0.1 mg kg-1 and pollen with up to 0.25 mg kg-1, and the most contaminated was bee bread with up to 23.6 mg kg-1 of the used fungicides. The results suggested that residues of vinclozolin and iprodione present in pollen grains are chemically modified (possibly conjugated) and thus undetected by the method used. During fermentation of bee bread the conjugates are hydrolysed and free pesticides released. Experiments showed that both vinclozolin and iprodione applied to old leaves were transported to young leaves and flowers. Thus, despite the contact mode of action declared by producers, they also show systemic properties. This assumption may be corroborated by the dynamics of pollen contamination (4-5 days of lag period between the spraytime and time of incidence of maximum contamination).