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diseases of impoRtant cRops in chiapas

mycelium within 4-5 da, which become darker as the spores mature. After ca. 3 mos, these
fruits dry and mummify on the trees and remain attached to the trunk, becoming the major

source of inoculum responsible for new waves of infection over a considerable period. Wind is

the main mode by which spores disperse, but human activities are also important; for example,

the long latent period on pods before visible symptoms develop allow an apparently healthy, sys-

tematically infected fruit to be transported and used as a source of planting material (Evans, 1981).

Mango (Mangifera indica)

Anthracnose. Anthracnose, caused most often by Colletotrichum gloeosporioides (teleomorph:

Glomerella cingulata), is the most important disease of mango in all but arid production areas

(Cook, 1975; Dodd et al., 1997; Ploetz and Prakash, 1997). It causes unsightly blemishes on fruit

and is a major pre- and postharvest problem, but can also damage foliage (Bose et al., 1973).

Small fruit can develop minute brown spots and abort if infected early in their development.

More commonly on immature fruit, the development of infections stops after an appressorium is

formed. Further development occurs after fruit mature and begin to ripen. Irregular, dark-brown
to black lesions develop that are somewhat depressed and can crack the fruit surface. Under hu-

mid conditions, large areas may be involved and orange to pinkish masses of conidia are formed

on the decaying surface. Lesions can form anywhere on fruit, but linear smears that radiate from

the stem end to the apex are common. Lesions on fruit are initially superficial, and penetrate

deeper than 5 mm into the mesocarp during the final stages of development.

New leaf flushes are the most significant sources of conidia; they are usually dispersed by

rainsplash, and infection requires free moisture (Jeffries et al., 1990). Although some mango
cultivars are moderately tolerant, none are sufficiently resistant to be produced without fungi-

cides in humid areas (Dodd et al., 1997). Fungicide application focuses on reducing damage to

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