Regular measurements of pH and salts will signal the onset of soil conditions that could favor development of these toxicities and deficiencies. In the cool temperatures at the beginning of the bedding plant season, unvented space heaters frequently injure plants. Smokestacks that are not tall enough may also cause phytotoxic fumes to be pulled back into a greenhouse through the vents. Ethylene, a gas that can result from incomplete combustion of fossil fuels, is sometimes formed in greenhouses when burners have insufficient oxygen. Ethylene can cause various plant symptoms, including distortion of terminal growth, inhibition of the apical meristem, flower drop, and leaf chlorosis.
Tomatoes are particularly sensitive and have been used as indicator plants.
All material is protected by Section 107 of the 1976 copyright law. Copyright is held by Cornell University and the New York State IPM Program. If you intend to use this material, please acknowledge the author and the source of the information.