ABSTRACT
I. INTRODUCTION Copper is one of seven micronutrient . elements identified as essential for proper development of higher forms of plant life (Chapter 10; Gupta, 1979). In relatively low concentrations, copper compounds are quite toxic to thallophyte organisms (i.e., fungi, bacteria, and algae). This property of toxicity has been utilized for over 100 years for control of fungal and bacterial diseases of plants (see Section II). In recent years there has been an increase in the use of these compounds for biocidal purposes. There are several reasons for this resurgence: (1) copper compounds are relatively safe; (2) development of resistance by pathogens has been minimal; organic fungicides show increased tolerance by pathogens after extended periods of use; (3) development of third world countries and the ever-increasing requirements for food; (4) increase in government regulations and restrictions or outright banning of alternative products due to their toxicological or environmental impact.
