|
(13-08) Assessment of quality criteria for the phytotoxicity of atmospheric ethylene under field conditions . Tonneijck, Alfred*,1, Van Dijk, Chris1, Grashoff, Kees1, Groenwold, Ko1, Schapendonk, Ad2, Dueck, Tom1, 1 Plant Research International, Wageningen, The Netherlands2 Plant Dynamics, Bennekom, The Netherlands ABSTRACT- Although ethylene is considered to be a minor air pollutant, its phytotoxic properties are relatively high. The current knowledge about effective levels of ethylene on plants is primarily based on continuous exposures under laboratorium conditions. There is however, increasing evidence that plants are less sensitive to discontinuous levels of ethylene under field conditions, such as those experienced in the vicinity of polyethylene manufacturing plants. This study has been undertaken to provide a better basis for permissible levels of ethylene, using the third level in a tiered approach, a semi-field experiment, to determine the phytoxicity of ethylene. Potato was chosen as model crop since it is relatively sensitive to ethylene and is an economically important crop. Research was begun by applying a crop growth simulation model followed by a field experiment. A potato crop was planted, placed under open-top chambers and exposed to realistic, discontinuous concentrations of ethylene, representative for those in the vicinity of emission sources. Plant performance during a complete growing season was examined with emphasis on tuber yield. The results are discussed in relation to air quality criteria on the basis of dose-response relationships and crop growth simulation modelling. Key words: Potato, crop growth simulation, plant performance, discontinuous exposure |
