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INTERACTION OF METHYL-TERT BUTYL ETHER AND WATER STRESS ON SEED GERMINATION AND SEEDLING GROWTH IN SOIL MICROCOSMS
Citation:
An, Y., D H. Kampbell*, AND W. G. Kirby. INTERACTION OF METHYL-TERT BUTYL ETHER AND WATER STRESS ON SEED GERMINATION AND SEEDLING GROWTH IN SOIL MICROCOSMS. Presented at the SETAC 23rd Annual Meeting, Salt Lake City, UT, November 16 - 20, 2002.
Impact/Purpose:
Our study was on the interactive influence of soil moisture stress and presence of MTBE on germination and seedling growth of wild oats(Avena sativa), sweet corn(Zea mays), wheat(Triticum aestivum), and lettuce(Lactuca sativa).
Description:
Methyl tert-butyl ether (MTBE) is a widespread contaminant in surface and ground water in the United States. Frequently irrigation is used to water fields to germinate planted seeds and sustain plant growth. A likely possibility exists that water used may have some MTBE. Our study was on the interactive influence of soil moisture stress and presence of MTBE on germination and seedling growth of wild oats(Avena sativa), sweet corn(Zea mays), wheat(Triticum aestivum), and lettuce(Lactuca sativa). Three different soil moisture contents(4, 8, 16%) and five different MTBE concentrations(75~1190 mg MTBE/kg soil as dry weight) were used. Toxic levels of MTBE with and without water stress were determined by measuring the median lethal concentration(LC50) and the median effective concentration(EC50). The LC50 and EC50 values in all test plkants decreased under water stress, indicating that seed germination and seedling growth were more reduced in all MTBE contaminated when there was water stress. An important result of the study was that the combined effect of MTBE and water stress on plants was similar to the effect of water stress only, while the plant response was similar when water was adequate and MTBE concentrations were higher.