ABSTRACT
Ethylene, unlike other plant hormomes, is a gas at physiological temperatures and, as a consequence, has relatively unique requirements for agricultural use. Based on the site of origin of the ethylene molecule, ethylene-producing compounds can be separated into three general classes. A number of chemically diverse compounds are capable of inducing the formation of ethylene by plants. These may be grouped, however, into two general classes based on their mode of action. The use of ethylene-releasing compounds has become extremely important in the production phase of agriculture. Ethylene-releasing compounds are used to induce flowering or promote the formation of pistillate flowers in several species. Ethylene-releasing compounds have also been shown to have potential for increasing disease resistance, frost tolerance, and bud hardiness in selected species. The intrinsic chemical characteristics of each ethylene-releasing compound strongly influence its field response and, therefore, its subsequent utility in agriculture. Plants vary widely in their susceptibility and response to exogenous ethylene.
