Herbicide Residue Determinations and Taint Tests on Fruit From Gooseberries Treated With Chlorthiamid and Dichlobenil

Abstract

Summary Fruit harvested from gooseberry plots treated with up to 33·6 kg/ha of chlorthiamid and dichlobenil (applied at two dates) was examined for the presence of residues of 2,6‐dichlorobenzonitrile together with the possible metabolites, 2,6‐dichlorobenzamide and 2,6‐dichlorobenzoic acid. In addition the canned fruit was examined for taint. Residues of 2,6‐dichlorobenzonitrile resulting from the application of both herbicides at all rates were below 0·05 ppm. Residues of 2,6‐dichlorobenzamide ranged from 0·13 to 0·45 ppm with the greatest residues occurring in fruit from plots treated with the highest amounts of chlorthiamid in March. Fruit from some of the March applications of both herbicides contained residues of up to 0·16 ppm 2,6‐dichlorobenzoic acid. No taints were found in the canned fruit.

Effect of Chlorthiamid on the Ascorbic Acid Content of Blackcurrants and Gooseberries

“…The ascorbic acid content of the blackcurrants agrees well with figures published by Brezina & Zuman (1958), but the level found in the gooseberries is considerably higher. These results, together with taint tests reported elsewhere (McKone, Hance & Burchill, 1971) indicate that chlorthiamid treatments on blackcurrants and gooseberries do not adversely affect, and indeed may enhance, the food quality of the fruit, if it is assumed that these crops are eaten primarily for their flavour and Vitamin C content.…”

Metabolism of the herbicide bromoxynil by Klebsiella pneumoniae subsp. ozaenae

“…Both microbial populations and tolerant plants can transform the cyano group of nitrilic herbicides. Soil perfusion studies have shown that the cyano group on both bromoxynil (7,19) and 2,6-dichlorobenzonitrile (15,17,23) can be hydrolyzed to the corresponding amide and carboxylic acid derivatives. Bromoxynil degradation by a Flexibacterium sp.…”

Utilização da análise por ativação neutrônica não destrutiva para determinação de alguns elementos em folhas de feijoeiros (>i<Phaseolus vulgaris>/i< L.) tratados com herbicidas

“…HAAG e BLANCO (1972) afirmaram que KURAMOTO et al (1968) observaram que o tratamento de plantas de café com diuron resulta va em um aumento no crescimento e teor de nutrientes em plantas, sendo que a utilizaç;o de níveis mais altos deste herbicida colabo rava para inibir o crescimento das plantas.O emprego de herbicidas. pode levar, também a um acúmulo de resíduos nas plantas� como constataramMcKONE et al (1971) ao verificar o acGmulo de �cido benz6ico e �etab61itos em frutas de groselha tratados com clortiamida e diclobenil.…”