The Response of Lemna minor to Mixtures of Pesticides That Are Commonly Used in Thailand

In the field, aquatic organisms are exposed to multiple contaminants rather than to single compounds. It is therefore important to understand the toxic interactions of co-occurring substances in the environment. The aim of the study was to assess the effects of individual herbicides (atrazine, 2,4-D, alachlor and paraquat) that are commonly used in Thailand and their mixtures on Lemna minor. Plants were exposed to individual and binary mixtures for 7 days and the effects on plant growth rate were assesed based on frond area measurements. Experimental observations of mixture toxicity were compared with predictions based on single herbicide exposure data using concentration addition and independent action models. The single compound studies showed that paraquat and alachlor were most toxic to L. minor, followed by atrazine and then 2,4-D. For the mixtures, atrazine with 2,4-D appeared to act antagonistically, whereas alachlor and paraquat showed synergism

"Wings of the Kite-Hawk" by Nicholas Rothwell. [review - radio script]

"Wings of the Kite-Hawk", subtitled "A Journey into the Heart of Australia", is journalist and novelist Nicolas Rothwell’s personal account of getting to know the interior of Australia: the tracks of the European explorers, the ancient sites and modern inhabitants, the landscapes; and the art, old and new, into which the landscape has been transformed by human hands. Rothwell’s interest is first aroused by the journals of the explorer Ludwig Leichhardt, and the book begins in Cape York, where he discovers traces of Leichhardt’s expedition. He is led from Leichhardt on to other inland explorers: Charles Sturt, Ted Strehlow and Ernest Giles. The book is loosely structured around his investigations of the trails of these men. But his interest is not in heroics or achievements. He sees them as writers and approaches them through their journals