A Simple Procedure to Overcome Polyethelene Glycol Toxicity on Whole Plants

Abstract

A procedure is described that can be used to minimize toxic effects of polyethylene glycol (PEG) to plants. The procedure is based on recycling nutrient solutions containing PEG-6000 through two plant cultures. Tomato plants grown in -0.3 megapascals PEG solutions used after two growth cycles exhibited minimal toxic effects. Long-term responses like dry matter production and chlorophyll content as well as short-term responses like CO(2) fixation rates and leaf conductance were severely inhibited by fresh PEG-6000 and only slightly reduced by recycled PEG-6000. Complete osmotic adjustment was obtained with tomatoes grown in recycled but not in fresh PEG solutions.