chlorophyll-a and 1-naphthol

Carbaryl application to soil collected from a rice fallow field was relatively less toxic to viable estimates of cyanobacteria and microalgae under nonflooded conditions than under flooded conditions. Application of 1-naphthol, the hydrolysis product of carbaryl, to soil under both the regimes increased the population of both cyanobacteria and microalgae. Soil application of carbaryl and 1-naphthol in combination, up to 1.0 kg ha(-1), was nontoxic to the viable population. The toxicity exerted by carbaryl and 1-naphthol towards growth, measured in terms of chlorophyll a, and nitrogenase activity was more pronounced in Anabaena spp. than in Nostoc spp.

Topics: Anabaena; Carbaryl; Chlorophyll; Chlorophyll A; Culture Media; Cyanobacteria; Floods; Hydrolysis; Microalgae; Naphthols; Nitrogen Fixation; Nitrogenase; Nostoc; Soil Microbiology

The toxic effects of carbaryl and its hydrolysis product, 1-naphthol, singly and in combination, towards a filamentous diazotrophic cyanobacterium, Anabaena torulosa, were determined. The toxicity criteria employed, viz., packed cell volume, chlorophyll a, phycocyanin, carotenoids, heterocyst differentiation and nitrogen fixation, were greatly affected by the toxicants above 25 micrograms/ml concentrations. However, 1-naphthol was more toxic to the diazotroph than was carbaryl. The toxicity was more pronounced when carbaryl and 1-naphthol were in combinations even at lower concentrations.

Topics: Anabaena; Carbaryl; Carotenoids; Chlorophyll; Chlorophyll A; Culture Media; Hydrolysis; Naphthols; Nitrogen Fixation; Phycocyanin