Tolerance of five mango cultivars to malformation disease in Mexico

Abstract

Mango malformation (Fusarium spp.) is one of most the severe diseases and is difficult to control in dry tropical areas worldwide. In Mexico, the disease reduces yields by up to 40–50%. In this study, the tolerance of two current mango cultivars (‘Ataulfo’ and ‘Haden’) and three recently introduced to Mexico (‘Rosigold’, ‘Mallika’ and ‘Nam Doc Mai’) to infection by Fusarium subglutinans (Fs) and F. mexicanum (Fm) was determined with a standardized inoculation procedure. The experiment was repeated and carried out in an experimental nursery located in Huamuxtitlan, Guerrero, Mexico, in 2015 and 2016. Each pathogenicity test was conducted on five healthy 6-month-old mango plants per cultivar by infiltration, singly and in combination, of Fs and Fm conidial suspension into the apical bud and the first three subapical (axillary) buds. The combination of Fusarium species induced higher severity (30.8%) than individual inoculation, independent of the cultivar. The incubation period before typical vegetative malformation symptoms was longer in ‘Ataulfo’ (267 d) than the rest of the cultivars (168–198 d). Comparatively, ‘Ataulfo’ also showed lower incidence (23.3%), disease severity index (3.6%), final severity (Yf = 0.6), infection rate (b−1 = 0.039) and area under the disease progress curve (AUDPC = 0.53). According to the severity scale used, ‘Ataulfo’ was tolerant, and ‘Nam Doc Mai’ and ‘Rosigold’ were susceptible, while ‘Mallika’ and ‘Haden’ were highly susceptible.