PREBIOTIC, Bacillus subtilis AND POTASSIUM PHOSPHITE ON ANTHRACNOSIS SEVERITY AND POST HARVEST QUALITY IN ‘MÉNDEZ’ AVOCADO

Abstract

Several factors affect the quality and safety of avocado (Persea americana Mill.) fruit during the production process, such as the agronomic management and climate. The objective of this research was to evaluate how foliar treatments affected postharvest control of anthracnose (Colletotrichum spp.) in two ‘Méndez’ avocado growing areas, Ziracuaretiro (ZI) and Salvador Escalante (SE), Michoacán, Mexico. Foliar sprays were used in the following treatments: 1) conventional management (CM) based on the technician’s experience; 2) integrated management (IM) including Bacillus subtilis, a prebiotic (BioKakimu®), and potassium phosphite; and 3) absolute control without foliar sprays. The effects of the treatments were evaluated on fruit harvested at physiological maturity while taking into account the severity of post-harvest anthracnose and fruit quality up to consumption maturity. During the evaluation period, disease damage was less than 10 % of the fruit surface in all three treatments. However, IM treatment delayed maturation time by 12.4 days in ZI and 10.6 days in SE. Fruits of the IM treatment lost less weight in ZI (7.6 %) than in SE (8.48 %) at eating maturity. Fruit firmness in ZI was higher in the IM and control treatments, while there were no differences in SE. The fruits in ZI and SE showed a decreasing color index profile for the three treatments. It is concluded that the phytopathogenic fungus in ‘Méndez’ was not exposed to weather conditions favorable for its development for an extended period of time, given that the first anthracnose alerts were emitted when the fruits were harvested. The crop management method did not result in an increase in the nutrient concentration of the fruit mesocarp.