Effects of pendimethalin at lower trophic levels--a review.
Pendimethalin's herbicidal action lies in its inhibition of the steps in plant cell division responsible for chromosome separation and cell wall formation. Terrestrial studies show that 10-20% of the herbicide evaporates during the first weeks after application. The remainder may dissipate biologically or chemically. Half-maximal dissipation time, or half-life (DT(50)) values vary from a few days to >200 days. Field and laboratory studies showed that reduced temperatures and drought prolong dissipation time to as long as 72-2094 days. In freshwater, pendimethalin concentrations reach 6 microg/L after runoff. In water the 10% lethal concentration (LC(10)) for Daphnia was 6 microg/L when exposed via suspended food. The LC(50) was 78 microg/L. An invertebrate field study showed that soil nematodes were reduced by 35-60% at pendimethalin application rates of 0.75 and 1.0 kg/ha, respectively. After application, soil microbiota is affected by pendimethalin for approximately 4 weeks. Plant-Rhizobium symbiosis is affected at application rates of 0.5-1.0 kg/ha.
Strandberg
Morten
M
Department of Terrestrial Ecology, National Environmental Research Institute, Vejlsøvej 25, DK-8600 Silkeborg, Denmark. mts@dmu.dk
Scott-Fordsmand
Janeck J
JJ
D000814:Aniline Compounds / Q000633:toxicity*; D000818:Animals; D003621:Daphnia; D004190:Disasters; D020387:Food Chain; D006207:Half-Life; D006540:Herbicides / Q000633:toxicity*; D007928:Lethal Dose 50; D009348:Nematoda; D018517:Plant Roots / Q000382:microbiology; D011157:Population Dynamics; D012231:Rhizobium / Q000502:physiology; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000633:toxicity*; D013696:Temperature
D000814:Aniline Compounds; D006540:Herbicides; D012989:Soil Pollutants; C030856:pendimethalin