Effect of Fungicide Applications on Populations of Phytophthora parasitica and on Feeder Root Densities and Fruit Yields of Citrus Trees

Fungicide treatments for control of feeder root rot of citrus caused by Phytophthora parasitica were made for 3 yr in four Florida orchards. Treatments consisted of foliar applications of fosetyl-Al at high (FOS-H) and low (FOS-L) frequency and soil applications of metalaxyl (MET). Propagule densities were positively correlated with feeder root densities in some orchards, especially in plots treated with fosetyl-Al (...)