Fungicidal control in pineapple and avocado of diseases caused by Phytophthora cinnamomi

Abstract

Root and heart rot diseases of pineapples and root rot of avocado caused by P. cinnamomi were controlled with fungicides. In pineapples, treatments were applied at planting and again after one and two months. Ridomil (0.8 kg a.i. ha-1) and Aliette (8 kg a.i. ha-1) controlled P. cinnamomi better than the standard Difolatan treatment (11 kg a.i. ha-1). In avocado nursery plants, Ridomil mixed with the soil before planting (1 g a.i. per 10 l soil) or drenched onto the soil surface around established plants (1 g a.i, per 10 1 container) controlled root rot for at least four months after treatment. Two applications of Ridomil, applied at a rate of 5 g a.i. m-2 as a soil drench beneath the canopy of 7 year old trees affected by root rot, controlled P. cinnamomi without affecting its biological antagonists and permitted trees to recover over a 12-month period.