ASHS 2024 Conference

Florida is perhaps the state in the U.S. most identified with citrus cultivation. The warm winters, abundant sunshine and significant rainfall are qualities which promote this industry, although other factors make producing these fruits on larger groves more arduous. These include limited nutrient concentrations, problematic drainage dynamics, and low organic matter and cation exchange capacity. Such issues combine to make citrus production in Florida highly dependent on external inputs of labor and material, both of which can be financially burdensome and demonstrate high volatility in price or availability from year to year. Cover crops have the potential to cost-effectively amend many soil issues in Florida citrus groves if they are established and maintained according to certain management practices. This principle was first presented at the Florida State Horticultural Society meeting in the late 1890s, and then clarified by Harold Hume in Citrus Fruits and their Culture in 1904. Later, the non-native legumes Crotolaria pallida and Crotolaria juncea were identified in multiple publications as soil-building cover crops which could be implemented into Floridian citrus production. Florida’s citrus production in the wake of World War II saw a decline in its incorporation of legume cover crops in favor of synthetic fertilizers. More modern research initiatives in Florida focused primarily on the mitigation of transmissible disease like Phytophthora root rot and citrus canker, a trend which has become more apparent following the discovery of citrus greening in 2005 and the stark decreases in yields this bacterial illness has been the primary cause of. In response, a number of Florida citrus growers have adopted cover crop mixes featuring legumes to supply disease-afflicted citrus roots with a sustainable and regular source of nitrogen. This presentation will review past literature and will also discuss current research on legume cover crops that have the potential to bolster citrus operations which is being conducted by individuals in the state of Florida.