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diseases of impoRtant cRops in chiapas

and F. sp. MP I in Brazil. In Mexico, a fourth taxon that is closely related to F. sp. MP I may be
responsible for the disease (Rodriguez-Alvarado et al., 2006).

Long-distance spread of the disease relies on the movement of infected nursery stock.

Over shorter distances the mango bud mite, Eriophyes mangiferae, may vector the pathogen

and facilitate infection via its feeding activities on epidermal cells of floral and vegetative buds.

F. mangiferae has a highly localized distribution within malformed mango trees (Ploetz, 1994),

and infections may remain latent for extended periods before symptoms develop.

New plantings should be established with pathogen-free nursery stock. Scion material

should never be taken from an affected orchard, and affected plants that are observed in the

nursery should be removed and destroyed. Nurseries should also not be established in or-
chards, especially when they are affected by malformation. Once the disease is found in an

orchard, removing symptomatic tissues from trees is usually effective (Ploetz, 2001). Affected

terminals and the subtending three nodes are cut from trees, removed from the field and

burned for 2 or 3 consecutive years. Thereafter, the disease can be kept in check by removing

symptomatic tissues every other year.

Stem-end rot. Stem-end rot is a postharvest disease that increases in importance as or-

chards become older and when preharvest fungicide programs reduce the incidence and se-
verity of anthracnose (Ploetz et al., 1994; Ploetz, 2003). Losses can increase during prolonged

storage at low temperatures, or when fruit ripen at >28°C. Variable symptoms are caused by

different fungi at the stem end upon ripening. Diplodia theobromae, Fusicoccum aesculi and F.

mangferum cause diffuse, water-soaked symptoms that spread from the stem end and darken.

Necrosis is subcuticular and may affect the entire mesocarp within a week at 25°C. Phomopsis

mangiferae produces dark lesions at the stem end that penetrate the mesocarp, but do not

spread as quickly as those cause by the above fungi. These lesions may resemble stem-end

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