Good control of P. cinnamomi was achieved with 2-yr-old ''Hass'' avocado nursery trees grafted on Duke 7 clonal rootstocks by using fosetyl-Al as a 3-l preplant application (500 .mu.g a.i.[active ingredient]/ml) 48 hr before planting and as a postplant soil treatment at either 70 or 35 g a.i./m2, 2 or 4 times/yr, respectively. Similar disease control was obtained using a mixture of metalaxyl and etridiazole (ethazol) in which the preplant dosages were 25 and 200 .mu.g a.i./ml and the postplant rates, applied twice per year, were 2 and 10 g a.i./m2 of metalaxyl and etridiazole, respectively. Twenty-year-old ''Fuerte'' avocados on Phytophthora-susceptible rootstocks severely infected with P. cinnamomi were pruned back to their scaffold limbs and treated with either metalaxyl or fosetyl-Al. Both fungicides restored fruit production within 2 yr. The most cost-effective treatment was a foliar spray (3 g a.i./l) of fosetyl-Al applied 3-5 times/yr.