Effects of amendments on the uptake and distribution of DDT in Cucurbita pepo ssp pepo plants

The effects of soil amendments on the phytoextraction of Sigma DDT (DDT + DDD + DDE) from soil ([Sigma DDT] similar to 1500 ng/g) by a pumpkin variety of Cucurbita pepo ssp pepo were tested and the patterns of Sigma DDT storage throughout the plant shoot were examined. The soil amendments did not increase the total amount of Sigma DDT extracted into plant shoots, but new information about Sigma DDT distribution in the plants was obtained. As observed previously, the Sigma DDT concentration in plant leaves (mean 290 ng/g) was significantly lower than in plant stems (mean 2600 ng/g). Further analysis revealed that Sigma DDT composition was consistent throughout the plant shoot and that Sigma DDT concentration in leaves and stems decreased exponentially as distance from the root increased, which was previously unknown. This new information about the patterns of Sigma DDT uptake and translocation within pumpkin plants highlights the need for appropriate plant sampling strategies in future POPs phytoextraction research. (C) 2009 Elsevier Ltd. All rights reserved.